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Bacterial adhesion on surfaces of medical, water and food applications may lead to infections, water or food spoilage and human illness. In comparison to traditional static and macro flow chamber assays for biofilm formation studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes, have better environment control and smaller sample requirements.
In this work, a novel microfluidic platform is developed to investigate biofilm adhesion under precisely controlled bacteria concentration, temperature, and flow conditions. This platform central unit is a single-inlet microfluidic flow cell with a 5 mm wide chamber designed and tested to achieve ultra-homogenous flow in the central area of chamber. Within this area, defined microstructures are integrated that will disturb the homogeneity of the flow, thus changing bacterial adhesion pattern.
Here we present the monitoring of bacterial biofilm formation in a microfluidic chip equipped with a microstructure known as micro-trap. This feature is based on a 3D bacteria trap designed by Di Giacomo et al. and successfully used to sequester motile bacteria.
At first, fluorescent particles similar in size to Escherichia coli (E. coli) are used to simulate bacteria flow inside the flow cell and at the micro-trap. The turbulences induced by the trap are analyzed by imaging and particle tracking velocimetry (PTV). Secondly, the model strain E. coli TG1, ideal and well described for biofilm studies, is used to analyze biofilm formation in the micro-trap. Therefore, a stable fluorescent strain E. coli TG1-MRE-Tn7-141 is constructed by using Tn7 transposon mutagenesis according to the method described by Schlechter et al. Sequestering of E. coli cells within the micro-trap was followed using epifluorescence microscopy.
The novel microfluidic platform shows great potential for assessment of bacterial adhesion under various flow regimes. The performance of structural feature with respect to the generation of turbulences that promote or reduce bacterial adhesion can be systematically examined.
The combination of flow analysis and fluorescent strain injection into the microfluidic chip shows that the micro-trap is useful for capturing bacteria at defined positions and to study how flow conditions, especially micro-turbulences, can affect biofilm formation. It represents a powerful and versatile tool for studying the relation between topography and bacteria adhesion.
Homochirality is an obvious feature of life on Earth. On the other hand, extraterrestrial samples contain largely racemic compounds. The same is true for any common organic synthesis. Therefore, it has been a perplexing puzzle for decades how these racemates could have formed enantiomerically enriched fractions as a basis for the origin of homochiral life forms. Numerous hypotheses have been put forward as to how preferentially homochiral molecules could have formed and accumulated on Earth. In this article, it is shown that homochirality of the abiotic organic pool at the time of formation of the first self-replicating molecules is not necessary and not even probable. It is proposed to abandon the notion of a molecular ensemble and to focus on the level of individual molecules. Although the formation of the first self-replicating, most likely homochiral molecule is a seemingly improbable event, on a closer look, it is almost inevitable that homochiral molecules have formed simply on a statistical basis. In this case, the non-selective leap to homochirality would be one of the first steps in chemical evolution directly out of a racemic “ocean”. Moreover, most studies focus on the chirality of the primordial monomers with respect to an asymmetric carbon atom. However, any polymer with a minimal size that allows folding to a secondary structure, would spontaneously lead to asymmetric higher structures (conformations). Most of the functions of these polymers would be influenced by this inherently asymmetric folding. To summarize, simple and universal mechanisms may have led to homochiral self-replicating systems in the context of chemical evolution. A homochiral monomer pool is deemed unnecessary and probably never existed on primordial Earth.
Fluorescent semiconductor nanocrystals, also known as quantum dots (QDs), enabled many advancements in biotechnology, photovoltaics, photocatalysis, quantum computing and display devices. The high versatility of this nanomaterial is based on their unique size-tunable photoluminescence properties, which can be adjusted from the visible to the near-infrared range. In contrast to other nanomaterials, QDs made the transition from a laboratory curiosity to the utilization in commercial products, like the QLED television screen or in smartphone displays. The best investigated QDs are composed of heavy metals like cadmium or lead, which is not the best choice in terms of toxicity and environmental pollution. A more promising material is Indium Phosphide (InP), which is also currently used by Samsung, Sony and co. in the QLED displays.
In this contribution, I would like to give you a sneak peek behind the curtains of nanomaterial synthesis and show how this material is produced, how to stabilize their structural properties, and assess their toxicity in environmentally relevant conditions. Furthermore, I would like to present a synthesis method to accomplish the last open challenge in display technology of a blue luminescent LED based on QDs by introducing a new element to the InP QDs.
Two nanosensors for simultaneous optical measurements of temperature (“T”), oxygen (“O”), and pH (“P”) have been designed. These “TOP” nanosensors are based on 100 nm-sized silica-coated polystyrene nanoparticles (PS-NPs) doped with the near infrared emissive oxygen- and temperature-sensitive chromium(III) complex ([Cr(ddpd)2][BPh4]3 CrBPh4)[1][2] and an inert reference fluorescence dye (Nile Red NR or 5,10,15,20tetrakis-(pentafluorophenyl) porphyrin TFPP) and are covalently labeled with the pHsensitive fluorophore fluorescein isothiocyanate (FITC). These emitters can be excited at the same wavelength and reveal distinguishable emission spectra suitable for ratiometric intensity-based and time-resolved studies in the visible and near infrared spectral region. The core-shell nanostructure of these sensors reveals high colloidal stability in various aqueous media. Studies in PBS buffer solutions and in a model body liquid demonstrate the applicability of the TOP nanosensors for optically detecting the three bioanalytically and biologically relevant analytes temperature, oxygen and pH simultaneously at the same position.
Two nanosensors for simultaneous optical measurements of temperature (“T”), oxygen (“O”), and pH (“P”) have been designed. These “TOP” nanosensors are based on 100 nm-sized silica-coated polystyrene nanoparticles (PS-NPs) doped with the near infrared emissive oxygen- and temperature-sensitive chromium(III) complex ([Cr(ddpd)2][BPh4]3 CrBPh4)[1][2] and an inert reference fluorescence dye (Nile Red NR or 5,10,15,20-tetrakis-(pentafluorophenyl) porphyrin TFPP) and are covalently labeled with the pH-sensitive fluorophore fluorescein isothiocyanate (FITC). These emitters can be excited at the same wavelength and reveal distinguishable emission spectra suitable for ratiometric intensity-based and time-resolved studies in the visible and near infrared spectral region. The core-shell nanostructure of these sensors reveals high colloidal stability in various aqueous media. Studies in PBS buffer solutions and in a model body liquid demonstrate the applicability of the TOP nanosensors for optically detecting the three bioanalytically and biologically relevant analytes temperature, oxygen and pH simultaneously at the same position.
Near-infrared (NIR) spectroscopy is a promising candidate for low-cost, nondestructive, and highthroughput mass quantification of microplastics in environmental samples. Widespread application of the technique is currently hampered mainly by the low sensitivity of NIR spectroscopy compared to thermoanalytical approaches commonly used for this type of analysis. This study shows how the application of NIR spectroscopy for mass quantification of microplastics can be extended to smaller analyte levels by combining it with a simple and rapid microplastic enrichment protocol. For this purpose, the widely used flotation of microplastics in a NaCl solution, accelerated by centrifugation, was chosen which allowed to remove up to 99 % of the matrix at recovery rates of 83–104 %. The spectroscopic measurements took place directly on the stainless-steel filters used to collect the extracted particles to reduce sample handling to a minimum. Partial least squares regression (PLSR) models were used to identify and quantify the extracted microplastics in the mass range of 1–10 mg.
The simple and fast extraction procedure was systematically optimized to meet the requirements for the quantification of microplastics from common PE-, PP-, and PS-based packaging materials with a particle size < 1 mm found in compost or soils with high natural organic matter content (> 10 % determined by loss on ignition). Microplastics could be detected in model samples at a mass fraction of 1 mg g-1. The detectable microplastic mass fraction is about an order of magnitude lower compared to previous studies using NIR spectroscopy without additional enrichment. To emphasize the cost-effectiveness of the method, it was implemented using some of the cheapest and most
compact NIR spectrometers available.
µ-FTIR spectroscopy is a widely used technique in microplastics research. It allows to simultaneously characterize the material of the small particles, fibers or fragments, and to specify their size distribution and shape. Modern detectors offer the possibility to perform two-dimensional imaging of the sample providing detailed information. However, datasets are often too large for manual evaluation calling for automated microplastic identification. Library search based on the comparison with known reference spectra has been proposed to solve this problem.
To supplement this ‘targeted analysis’, an exploratory approach was tested. Principal component analysis (PCA) was used to drastically reduce the size of the data set while maintaining the significant information. Groups of similar spectra in the prepared data set were identified with cluster analysis. Members of different clusters could be assigned to different polymer types whereas the variation observed within a cluster gives a hint on the chemical variability of microplastics of the same type. Spectra labeled according to the respective cluster can be used for supervised learning. The obtained classification was tested on an independent data set and results were compared to the spectral library search approach.
Working towards a comprehensive understanding of introduction pathways, number, and fate of micro¬plastics in the environment, suitable analytical methods are a precondition. Micro-spectroscopic methods are probably the most widely used techniques. Besides their ability to measure single spectra of a particle or fiber, most modern FTIR- and Raman microscopes are also capable of two-dimensional imaging. This is very appealing to microplastics research because it allows to simultaneously characterize the analytes chemically as well as their size (distribution) and shape.
Two-dimensional imaging on extensive sample areas with FTIR-micros¬copes is facilitated by focal plane array (FPA) detectors resulting in large data sets comprised of up to several million spectra. With numbers too large for manual inspection of each individual spectrum, automated data evaluation is inevitable. Identifying different polymers based on the comparison with known reference spectra (library search) has proven to be a suitable approach. For that purpose, FTIR-spectra of common plastics can be collected to create an individual reference library.
To Supplement this ‘targeted analysis’, looking for known substances via library search, an exploratory approach was tested. Principal component analysis (PCA) proved to be a helpful tool to drastically reduce the size of the data set while maintaining the significant information. Subsequently, cluster analysis was used to find groups of similar spectra. Spectra found in different clusters could be assigned to different polymer types. The variation observed within clusters gives a hint on chemical variability of microplastics of the same polymer found in the sample. Spectra labeled according to the respective cluster/polymer type were used to build a classification model which allowed to quickly predict the polymer type based on the FTIR spectrum. Classification was tested on a second, independent data set and results were compared to the spectral library search procedure.
Für die Erfassung der Verbreitung von Mikroplastik (MP) in der Umwelt ist die zeit- und kostenaufwendige Analysestrategie und der damit verbundene geringe Probendurchsatz eine limitierende Größe. Eine große Zahl verschiedener Studien dokumentriet das Auftreten von MP über den gesamten Globus. Meist sind die Studien aufgrund des großen analytischen Aufwands auf exemplarische, stichpunktartige Untersuchungen kleiner Umweltaliquoten und zahlenmäßig kleiner Probenumfänge begrenzt. Um die Verbreitung, die Eintragspfade und den Verbleib von MP in der Umwelt besser zu verstehen und effektive Vermeidungsstrategien abzuleiten, ist es jedoch notwendig, analytisch mehr Proben erfassen zu können.
Bildgebende mikro-spektroskopische Methoden wie das Raman- und FTIR-Imaging ermöglichen eine zeitaufwendige, umfassende Charakterisierung kleiner Umweltaliquoten. Neben der Partikelanzahl sind zusätzlich Informationen zu Partikelgröße, Größenverteilung und Oberflächenmorphologie zugänglich. Chemische und thermische Extraktionsverfahren sind bereits deutlich schneller und können diese Informationen durch eine Massenbilanz vervollständigen. Die analysierbare Probenmenge ist jedoch auf Milligramm Mengen beschränkt.
Wir schlagen daher vor, die Analyse von Proben auf MP durch ein vorangestelltes Screening mit der Nahinfrarot-Spektroskopie (NIRS) zur komplementieren. In diesem wird bereits eine erste Einschätzung über die Präsenz von MP in einer Probe gefällt und dadurch die wertvolle Messzeit anderer Methoden effizienter genutzt.
NIR zur Analyse von Polymeren wird seit langem eingesetzt, jedoch bisher lediglich im Rahmen einer Studie zur Mikroplastikuntersuchung mittels Hyperspektraler Bildgebung beschrieben. Der NIR Spektralbereich findet sich zwischen dem sichtbaren Licht und dem mittleren Infrarot (MIR). MIR Spektren sind durch klar definierte Banden charakterisiert, welche mehrheitlich von den Grundschwingungen der Moleküle stammen. Die höheren Energien im nahen Infrarot regen hingegen Kombinations- und Oberschwingungen der Streck und Biegeschwingungen an. Die resultierenden Absorptionsbanden sind oft breit und relativ unspezifisch. Erst mit Hilfe einer computergestützten Datenauswertung lassen sich aus diesen Spektren nützliche Informationen gewinnen. Dies erklärt die steigende Popularität der NIR-Spektroskopie in der jüngeren Vergangenheit mit einem Schwerpunkt als prozessanalytische Methode. NIR Spektrometer für das industrielle Prozessmonitoring zeichnen sich durch eine kompakte und robuste Konstruktionsweise aus. Die verfügbaren faseroptischen Reflexionssonden eignen sich gut um pulverförmige Proben zu untersuchen. Der räumlich erfassbare Messbereich kann durch die Sondengeometrie variiert werden. Sind die untersuchten Partikel im Verhältnis zur abgetasteten Fläche klein, wird als spektrale Information die Summe der Absorption aller Partikel im Sichtfeld erfasst. Die Methode ist deshalb nicht für Detailuntersuchungen von MP geeignet, erlaubt es jedoch innerhalb weniger Minuten eine Einschätzung über das Vorkommen von Mikroplastik in einer Probe zu treffen.
Exemplarisch wurden für diese Untersuchungen vier der am weitesten verbreiteten Kunststoffe Polyethylen (PE), Polyethylenterephthalat (PET), Polypropylen (PP) und Polystyrol (PS) gewählt. Aus den additivfreien Polymeren wurden nach einer Kryo-vermahlung und anschließender Siebung (< 125 µm) Modellproben generiert. Die Polymere wurden dafür zu einem Massenanteil von 1 % mit einem Standardboden (LUFA2.3, gesiebt < 125 µm) vermischt. Die Gesamtmenge von 1 g je Probe wurde in Aluminiumbehältern präpariert und 8 Messungen an unterschiedlichen, zufällig gewählten Positionen vorgenommen. Die erhaltenen Spektren wurden zur Kalibrierung chemometrischer Modelle genutzt.
In einem hierarchischen Ansatz wurde anhand der NIR-Spektren eine Klassifizierung vorgenommen:
1. Bestimmung ob eine Probe MP enthält (Ja/Nein).
2. Identifikation der Polymere in der Probe.
Eine aussagekräftige Klassifizierung beruht auf einer Vorbehandlung der Spektren. Hierdurch werden die Unterschiede zwischen den einzelnen Polymerbanden hervorgehoben. Die Eignung der so erstellten Modelle wurde anhand eines Referenzmaterials und am Beispiel von Realproben erfolgreich getestet. Dabei zeigte sich, dass nicht nur in den erstellten Polymer-Bodenmischungen, sondern auch in den Rückständen von fermentiertem Bioabfall und in Filterrückständen einer Waschmaschine, MP richtig erkannt wurde. Weiterhin zeigten Tests mit Mikroplastik-freien Bodenproben unterschiedlicher Herkunft, dass keine falsch-positive Resultate erzeugt wurden. Alle vier untersuchten Polymere, d.h. PE, PET, PS und PP mit einem Massenanteil von 1 % in einer Bodenmatrix werden auch bei einer gemischten Polymerzusammensetzung mit der NIR-Spektroskopie erkannt.
Der kombinierte Einsatz von NIRS und Chemometrie ermöglicht die Entscheidung über ein potenzielles Vorkommen sowie die Zuordnung des Materials der enthaltenen Polymerpartikel für eine Massefraktion ≥ 1 % in einer (trockenen) Probenmenge von 1 g innerhalb von 10–15 min. Der zeitaufwendige Schritt der Methode liegt hier in der Erstellung geeigneter chemometrischer Modelle sowie deren Validierung. Wesentliche Voraussetzung ist dabei, dass bei der Kalibrierung die Varianz der zu erwartenden Partikel und der Matrix realistisch abgebildet wird.
Herein, we present the development of a gas chromatographic method for Determination of warfarin, its TPs, and selected metabolites.
TPs were formed by applying UV-irradiation, ozonation, and an electrochemical cell coupled to mass spectrometry to mimic the oxidative phase I metabolism. The further aim is to use this method for detection and quantification under environmentally relevant conditions, as well as, toxicological assessment.
Herein, we present liquid and gas chromatographic methods coupled with
(high-resolution) mass spectrometry for the analysis of warfarin’s TPs.
Methodologies such as UV-irradiation, ozonation, and chlorination were
utilized to simulate primarily technical water treatment, as well as, abiotic transformation processes. Examination of resulting compounds by numerous analytical methods has provided first insights into a multitude of formed substances. Moreover, the oxidative phase I metabolism was mimicked by an electrochemical flow cell with the aim to synthesize and confirm major metabolic products via a nonbiologically mediated process. The further aim is the toxicological assessment of relevant TPs, as well as, the quantification of warfarin and its TPs under environmentally relevant conditions employing the introduced methodologies.
Herein, we present liquid and gas chromatographic methods coupled to (high-resolution) mass spectrometry for the analysis of warfarin’s transformation products.
Methodologies such as UV-irradiation, ozonation, and chlorination were utilised to simulate technical water treatment. Resulting compounds were elucidated and examined by numerous analytical methods. Moreover, the oxidative phase I metabolism was mimicked by an electrochemical flow cell to synthesise and confirm major metabolites. The further aim is the toxicological assessment of all substances formed, as well as, the quantification of warfarin and its TPs under environmentally relevant conditions employing the introduced methods.
Warfarin ist seit den 1950er Jahren einer der bekanntesten Gerinnungshemmer. Beim Menschen wird es bis heute zur Vorbeugung von Thrombose und der Behandlung von Vorhofflimmern und Arrhythmie eingesetzt. Doch schon einige Jahre vor der FDA Zulassung (U. S. Food and Drug Administration) als Medikament wurde es zur Bekämpfung von Nagetieren eingesetzt. Bis heute wurde es nur teilweise durch weitaus wirksamere antikoagulante Rodentizide (ARs) der zweiten Generation, sogenannte Superwarfarine, ersetzt.
In der Fachliteratur finden sich zahlreiche Beispiele für sekundäre und tertiäre Vergiftung mit ARs bei Wildtieren und anderen Nichtzieltieren. Bisher ist relativ wenig über die Bioakkumulation, Persistenz und Toxizität von ARs und deren Transformationsprodukten (TPs) in der terrestrischen und aquatischen Umwelt, sowie der Nahrungskette bekannt.
Um Einblicke in mögliche Transformations- und Abbauprozesse von Warfarin unter umweltrelevanten Bedingungen zu erhalten und um diese Einflüsse zu simulieren, wurde hierzu eine elektrochemische Reaktorzelle in Kopplung mit einem Massenspektrometer verwendet. So können mögliche Phase-I-Metabolite und sogenannte „oxidation products“ vorausgesagt werden. Hinsichtlich des Verhaltens während der Wasseraufbereitung in Kläranlagen wurden technisch relevante Prozesse wie Chlorung, UV-Bestrahlung und Ozonung in Modellen simuliert, um hier potenzielle Abbauwege und -prozesse aufzuklären. Gebildete Transformationsprodukte wurden daher mittels unterschiedlicher chromatografischer Verfahren getrennt und massenspektrometrisch identifiziert, charakterisiert und verglichen.
Warfarin ist seit den 1950er Jahren einer der bekanntesten Gerinnungshemmer. Beim Menschen wird es bis heute zur Vorbeugung von Thrombose und der Behandlung von Vorhofflimmern und Arrhythmie eingesetzt. Doch schon einige Jahre vor der FDA Zulassung (U. S. Food and Drug Administration) als Medikament wurde es zur Bekämpfung von Nagetieren eingesetzt. Bis heute wurde es nur teilweise durch weitaus wirksamere antikoagulante Rodentizide (ARs) der zweiten Generation, sogenannte Superwarfarine, ersetzt. In der Fachliteratur finden sich zahlreiche Beispiele für sekundäre und tertiäre Vergiftung mit ARs bei Wildtieren und anderen Nichtzieltieren. Bisher ist relativ wenig über die Bioakkumulation, Persistenz und Toxizität von ARs und deren Transformationsprodukten (TPs) in der terrestrischen und aquatischen Umwelt, sowie der Nahrungskette bekannt.
Um Einblicke in mögliche Transformations- und Abbauprozesse von Warfarin unter umweltrelevanten Bedingungen zu erhalten und um diese Einflüsse zu simulieren, wurde hierzu eine elektrochemische Reaktorzelle in Kopplung mit einem Massenspektrometer verwendet. So können mögliche Phase-I-Metabolite und sogenannte „oxidation products“ vorausgesagt werden. Hinsichtlich des Verhaltens während der Wasseraufbereitung in Kläranlagen wurden technisch relevante Prozesse wie Chlorung, UV-Bestrahlung und Ozonung in Modellen simuliert, um hier potenzielle Abbauwege und -prozesse aufzuklären. Gebildete Transformationsprodukte wurden daher mittels unterschiedlicher chromatografischer Verfahren getrennt und massenspektrometrisch identifiziert, charakterisiert und verglichen.
The introduction of fluorine in organic molecules leads to new chemical/physical properties. Especially in the field of pharmaceuticals, fluorinated organic molecules are becoming more and more popular and at present amount up to 25% of market share, with an upward trend. The main benefits of fluorinated pharmaceuticals are: (i) enhanced fat solubility; (ii) enhanced interaction of catalytic-center of enzymes with fluorine-drugs; (iii) a delayed metabolism within the human body. Highly fluorinated organic substances are also used in technical applications (e.g. coatings, fire-extinguishing agents).
Due to the broad variety of fluorinated substances and increasing production volumes numerous and up to date unknown fluorine-species are most likely to be present in the (aquatic) environment. Analytical methods to assess the degree of contamination of surface waters with organically bound fluorine are highly needed and up to now only combustion ion chromatography based method is available, which is relatively laborious.
Since a few years’ high resolution-continuum source-graphite furnace atomic absorption spectrometers (HR-CS-GFAAS) are commercially available from Analytik Jena. By means of this technique, the detection of high resolution molecular absorption spectra (MAS) is enabled. Thus, fluoride is detectable upon the addition of a modifier and the formation of a diatomic molecule (e.g. GaF). Just recently, we applied this technique for total fluorine (mainly dissolved fluoride) analysis in river water samples.
In the present work a HR-CS-GFMAS method for extractable organically bound fluorine (EOF) analysis in surface water samples was developed by us. The method is based on SPE extraction of organically bound fluorine even in the presence of high fluoride concentrations followed by HR-CS-GFMAS analysis upon elution. Due to high enrichment factors, LODs in the low ng/L range were achieved. We successfully applied our SPE HR-CS-GFMAS method to Rhine water samples and EOF in the range of about 50-300 ng/L was detectable.
The introduction of fluorine in organic molecules leads to new chemical/physical properties. Especially in the field of pharmaceuticals, fluorinated organic molecules are becoming more and more popular and at present amount up to 25% of market share, with an upward trend. The main benefits of fluorinated pharmaceuticals are: (i) enhanced fat solubility; (ii) enhanced interaction of catalytic-center of enzymes with fluorine-drugs; (iii) a delayed metabolism within the human body. Highly fluorinated organic substances are also used in technical applications (e.g. coatings, fire-extinguishing agents).
Due to the broad variety of fluorinated substances and increasing production volumes numerous and up to date unknown fluorine-species are most likely to be present in the (aquatic) environment. Analytical methods to assess the degree of contamination of surface waters with organically bound fluorine are highly needed and up to now only combustion ion chromatography based method is available, which is relatively laborious.
Since a few years’ high resolution-continuum source-graphite furnace atomic absorption spectrometers (HR-CS-GFAAS) are commercially available from Analytik Jena. By means of this technique, the detection of high resolution molecular absorption spectra (MAS) is enabled. Thus, fluoride is detectable upon the addition of a modifier and the formation of a diatomic molecule (e.g. GaF). Just recently, we applied this technique for total fluorine (mainly dissolved fluoride) analysis in river water samples.
In the present work a HR-CS-GFMAS method for extractable organically bound fluorine (EOF) analysis in surface water samples was developed by us. The method is based on SPE extraction of organically bound fluorine even in the presence of high fluoride concentrations followed by HR-CS-GFMAS analysis upon elution. Due to high enrichment factors, LODs in the low ng/L range were achieved. We successfully applied our SPE HR-CS-GFMAS method to Rhine water samples and EOF in the range of about 50-300 ng/L was detectable.
Introducing fluorine into organic molecules leads to new chemical/physical properties. Up to now, the OECD identified and categorized 4730 per- and polyfluoroalkyl substances-related CAS numbers. Especially in the field of technical applications (e.g. surface coatings, fire extinguishing foams) as well as pharmaceuticals, fluorinated substances gain in importance. Thus, an increasing release of fluorinated compounds into the environment is expected.
The high environmental persistence of perfluorinated compounds leads to the risk of bioaccumulation. Partially fluorinated substances (polyfluorinated compounds) undergo degradation; thus, further possible fluorine species occur, which may exhibit different toxic/chemical properties. However, current target methods (e.g., HPLC/MS-MS) are not applicable for a comprehensive screening as well as assessment of pollution.
Thus, the poster presents a new sum parameter method for quantitative determination of extractable organically bound fluorine (EOF) in surface water samples. The method is based on solid-phase extraction (SPE) for fluorinated compounds as well as quantitative separation of interfering inorganic fluoride in combination with high-resolution-continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) for quantitative analysis. By means of this technique, the detection of high resolution molecular absorption spectra (MAS) is enabled upon the addition of a modifier and the formation of a diatomic molecule (e.g. GaF)
After successful optimization of the SPE procedure (maximum concentration of extractable organic fluorine), enrichment factors of about 1000 were achieved, allowing for highly sensitive fluorine detection. Next to a species-unspecific response, limits of detection in the low nanogram per liter range were achieved and real surface water samples were analyzed. EOF values in the range of about 50-300 ng/L were detected.
The developed method allows for a fast and sensitive as well as selective screening of organically bound fluorine (EOF) in surface water samples, helping to elucidate pollution hotspots as well as discharge routes.
Elementanalytische Verfahren werden heute zu mehr eingesetzt als bloß zur Bestimmung von Metallgesamtgehalten in diversen Probenmatrizes. Sie stellen heute ein wichtiges Werkzeug zur Beantwortung lebenswissenschaftlicher Fragen aus Umwelt, Medizin und Biologie dar. In der vorliegenden Arbeit kommt die single-cell-ICP-Flugzeitmassenspektrometrie (single-cell-ICP-TOF-MS) zur Multielementanalytik in einzelnen Kieselalgen (Diatomeen) zum Einsatz und wird zukünftig ein wichtiges Werkzeug z.B. bei der Beantwortung
ökotoxikologischer Fragestellung sein.
Technology critical elements (TCE) are key materials for high-tech products such as smartphones, notebooks and monitors. Their demand is expected to increase exponentially as a result of the shift towards greener economy through the deployment of renewable energy and electro mobility solutions (European Green Deal). This and the lack of natural resources in the EU, puts the market under pressure and leads to increasing prices. The need to secure TCE supply has become even more pressing under the current health crisis and it is a major objective of the Covid-19 Recovery Plan aimed at reinforcing Europe’s resilience and autonomy. A sustainable solution for solving this problem is first through recycling and finally through a circular economy. However, the analysis of waste streams is a complicating factor and requires suitable analytical solutions first, which need to be traceable to the SI to allow for comparability of measurement results throughout the recycling process or the circular economy. The required reference materials certified for TCE in the corresponding waste or secondary raw materials and specific documentary standards for TCE to comply with ISO/IEC 17025 requirements, however, are lacking. Furthermore, wastes from the urban mine are extremely heterogeneous, which makes the estimation of their TCE content difficult. Currently there is a lack of knowledge at the European level about the TCE stocks and flows in the urban mine. Given the high volume of waste generated and received, fast reliable analytical methods as well as sampling and sample preparation strategies are needed to determine the economic value of the waste and of the final product and to develop recycling procedures. Within this project we focus on a set of TCEs(Co, Ga, Ge, In, Ta, Nd, Pr, Dy, Gd, La, Au, Pt, Pd, Rh), which have been selected from the list of critical elements for Europe established by the EU in 2017. The overall objective of the project is to provide reliable and SI traceable determination of TCE in urban waste material at µg/g levels in order to increase the efficiency and accuracy of TCE recycling. This will be realized by developing validated SI-traceable reference methods, developing traceable and validated reference materials for the TCEs, validating the use of the routine methods and reference materials for real world applications and facilitating the take up of the technology and measurement infrastructure developed in the project by the measurement supply chain, standards developing organisations and end users.
Technologie-kritische Elemente (TCE) sind unentbehrliche Materialien für High-Tech Produkte wie Smartphones, Notebooks und Monitors. Ihr Bedarf wird voraussichtlich aufgrund des gesellschaftlichen Wandels hin zu einer grünen Ökonomie exponentiell ansteigen. Dieser Wandel wird vor allem auch durch erneuerbare Energien und Elektromobilität geprägt (European Green Deal). Diese Entwicklung in Verbindung mit einer nahezu fehlenden TCE Produktion in Europa setzt den Markt unter Druck und führt zu steigenden Preisen. Die Sicherung des TCE Nachschubs wurde in der gegenwärtigen Gesundheitskrise noch dringender und wurde daher auch zu einem der Hauptthemen des COVID-19 Recovery Plan, der eine Stärkung der europäischen Resilienz und Autonomie zum Ziel hat. Ein nachhaltige Lösung ist das Recycling der Abfall- bzw. Wertstoffe und letztendlich eine Circular Economy. Allerdings ist die Analyse von Abfallströmen schwierig und erfordert geeignete analytische Lösungen, die SI-rückführbare und somit vergleichbare Messergebnisse im gesamten Recyclingprozess ermöglichen. Die dafür erforderlichen, für TCE zertifizierte, Referenzmaterialien und nötige standardisierte Verfahren fehlen bisher nahezu vollständig. In diesem Beitrag werden die analytischen Herausforderungen, wie z.B. die extreme Heterogenität der Materialien, Schwierigkeiten beim Probenaufschluss und das Fehlen von Referenzmaterialien diskutiert. Und es wird das EMPIR-Projekt MetroCycleEU vorgestellt, dessen Ziel es ist Referenz- und Routineverfahren für ausgewählte TCE (Co, Ga, Ge, In, Ta, Nd, Pr, Dy, Gd, La, Au, Pt, Pd, Rh) zu entwickeln und Referenzmaterialien für Platinen, LEDs und Li-Batterien bereitzustellen.
Technology critical elements (TCE) are key materials for high-tech products such as smartphones, notebooks and monitors. Their demand is expected to increase exponentially due to the shift towards greener economy through the deployment of renewable energy and electro mobility solutions (European Green Deal). This and the lack of TCE production within the EU, puts the market under pressure and leads to increasing prices. The need to secure TCE supply has become even more pressing under the current health crisis and it is a major objective of the Covid-19 Recovery Plan aimed at reinforcing Europe’s resilience and autonomy. A sustainable solution is effective recycling and finally a circular economy. However, the analysis of waste streams is difficult and requires suitable SI traceable analytical solutions to allow for comparability of measurement results throughout the recycling process. The required reference materials (RMs) certified for TCE in the corresponding waste or secondary raw materials and specific documentary standards for TCE to comply with ISO/IEC 17025 requirements, however, are lacking. Furthermore, waste from the so-called “urban mine” is extremely heterogeneous making the estimation of its TCE content difficult. Currently, there is a lack of knowledge at the European level about the TCE stocks and flows in the urban mine. Given the high volume of waste generated and received, fast reliable analytical methods as well as sampling and sample preparation strategies are needed to determine the economic value of the waste and of the final product and to develop and improve recycling procedures.
Within this project we focus on TCEs (Co, Ga, Ge, In, Ta, Nd, Pr, Dy, Gd, La, Au, Pt, Pd, Rh), which have been selected from the list of critical elements for Europe established by the EU in 2020. The overall objective of the project is to provide the reliable and SI traceable determination of TCE in urban waste material at µg/g levels to increase the efficiency and accuracy of TCE recycling. This will be realized by developing validated SI-traceable reference methods, developing traceable and validated RMs for the TCEs, validating the use of the routine methods and RMs for real world applications and facilitating the take up of the technology and measurement infrastructure developed in the project by the measurement supply chain, standards developing organizations and end users.
This presentation will give an overview of the consortium, the project structure and the planned research. First activities will be presented as well.
Per- and polyfluoroalkyl substances (PFAS) are chemicals which were developed to improve humanity’s quality of life. Due to their high chemical stability and resistance to degradation by heat or acids, PFAS were used in a variety of consumer products. The continuous use of PFAS in household products and the discharge of PFAS from industrial plants into the sewer system resulted in the contamination of effluents and sewage sludge from wastewater treatment plants (WWTPs) (Roesch et al. 2022). Since sewage sludge is often used as fertilizer, its application on agricultural soils has been observed as a significant entry path for PFAS into the environment, specifically in our food chain. In Germany the sewage sludge/biosolid application on agricultural land was banned with the amendment of the German Sewage Sludge Ordinance and by 2029 sewage sludge application will be totally prohibited. However, phosphorus (P) from sewage sludge should still be recycled in WWTPs of cities with a population larger than 50,000 residents. To produce high-quality P-fertilizers for a circular economy, PFAS and other pollutants (e.g. pesticides and pharmaceuticals) must be separated from sewage sludge. Due to the strong diversity of industrial PFAS usage it is not clear if a safe application of novel recycled P-fertilizers from WWTPs can be guaranteed. Therefore, we analyzed various sewage sludges and wastewater-based fertilizers. Sewage sludge (SL) samples from various WWTPs in Germany and Switzerland, six sewage sludge ashes (SSA) from Germany, six thermally treated SL and SSA samples with different additives (temperatures: 700-1050 °C), two pyrolyzed SL samples (temperature: 400 °C) and two struvite samples from Germany and Canada were analyzed. The goal was to quantify PFAS in sewage sludges and wastewater-based P-fertilizers with the sum parameter extractable organic fluorine (EOF) by combustion ion chromatography (CIC). The results were compared with data from classical LC-MS/MS target analysis as well as selected samples by HR-MS suspect screening. The EOF values of the SLs mainly range between 154 and 538 µg/kg except for one SL which showed an elevated EOF value of 7209 µg/kg due to high organofluorine contamination. For the SSA samples the EOF values were lower and values between LOQ (approx. 60 µg/kg) and 121 µg/kg could be detected. For the pyrolyzed SLs no EOF values above the LOQ were detected. Moreover, the two wastewater-based struvite fertilizers contain 96 and 112 µg/kg EOF, respectively. In contrast to the EOF values, the sum of PFAS target values were relatively low for all SLs. Additional applied PFAS HR-MS suspect screening aimed to tentatively identify PFAS that could contribute to the hitherto unknown part of the EOF value. The majority of the detected fluorinated compounds are legacy PFAS such as short- and long-chain perfluorocarboxylic acids (PFCA), perfluorosulfonic acids (PFSA), polyfluoroalkyl phosphate esters (PAPs) and perfluorophosphonic acids (PFPA). Moreover, fluorinated pesticides, pharmaceutical as well as aromatic compounds were also identified, which are all included in the EOF parameter. Our research revealed that the current PFAS limit of 100 µg/kg for the sum of PFOS + PFOA in the German Fertilizer Ordinance is no longer up to date. Since the number of known PFAS already exceeds 10,000, the ordinance limit should be updated accordingly. Recent regulations and restrictions on using long-chain PFAS (≥C8) have resulted in a significant shift in the industry towards (ultra-)short-chain alternatives, and other, partly unknown, emerging PFAS. Ultimately, also fluorinated pesticides and pharmaceuticals, which end up as ultrashort PFAS in the WWTPs, have to be considered as possible pollutants in fertilizers from wastewater, too.
Gegenstand dieser Arbeit ist die Untersuchung eines bestehenden pyrometallurgischen Prozesses zur Rückgewinnung von Tantal und Niob aus metallurgischen Reststoffen mit vorwiegend niedriger Wertstoffkonzentration.
Zur näheren Erforschung der im vorliegenden Stoffsystem ablaufenden Reduktionsprozesse wurden in einem Elektrolichtbogenofen Schmelzversuche im Pilotmaßstab durchgeführt. Als Reduktionsmittel diente Koks, welcher mithilfe einer Argon-gespülten Eisenlanze in die flüssige mineralische Schmelze eingebracht wurde. Während der Reduktionsbehandlung werden Refraktärmetalle wie Tantal und Niob in ihre Carbide überführt und anschließend in der erschmolzenen eisenbasierten Metallphase am Boden des Reaktors angereichert. Neben Tantal und Niob gelangt auch ein Teil des im Einsatzmaterial enthaltenen Titans als unerwünschtes Begleitelement in die Metallphase.
Sein Großteil verbleibt jedoch als Oxid in der Schlacke und wird dort hauptsächlich im Mineral Perowskit (CaTiO3) gebunden. Die erstarrten Schlackeproben wurden mit verschiedenen Methoden wie Röntgenfluoreszensanalyse, Röntgenbeugung und Rasterelektronenmikroskopie mit gekoppelter energiedispersiver Röntgenanalyse untersucht, um die Bildung tantalhaltiger Mineralphasen zu verschiedenen Stadien des Reduktionsprozesses zu verfolgen.
Die hier gewonnenen Erkenntnisse zeigen, dass weniger die durch das Einblasen von Koks verursachte Reduktionsreaktion, sondern das Absinken der tantalreichen Eisentröpfchen in der flüssigen mineralischen Schmelze, gefolgt von ihrer Anreicherung in die Metallphase, für die Kinetik ausschlaggebend ist.
Fused filament fabrication (FFF) on desktop 3D printers is a material extrusion-based technique often used by educational institutions, small enterprises and private households. Polymeric filaments are melted and extruded through a heated nozzle to form a 3D object in layers. The extrusion temperature is therefore a key parameter for a successful print job, but also one of the main driving factors for the emission of harmful air pollutants, namely ultrafine particles and volatile organic gases, which are formed by thermal stress on the polymeric feedstock. The awareness of potential health risks has increased the number of emission studies in the past years. However, the multiplicity of study designs makes an objective comparison of emission data challenging because printer hardware factors such as the actual extruder temperature (TE) and also feedstockspecific emissions are not considered. We assume that across the market of commercial low- and mid-price FFF printers substantial deviations between actual and set extruder temperatures exist, which have a strong effect on the emissions and hence may bias the findings of exposure studies. In our last publication, we presented a standardized feedstock-specific emission test method and showed that for each investigated feedstock an increase in actual extruder temperature was accompanied by an increase in particle emissions (Tang and Seeger, 2022). Therefore, any systematic discrepancy between set and actual extruder temperature matters. In this study, we used a thermocouple and an infrared camera to measure the actual extruder temperatures at different heights. We found significant under- and overestimation of the actual extruder temperatures by the respective set temperatures in three commercial printers. This caused a broad variation of the measured total numbers of emitted particles (TP), even when the same feedstock was operated. For the determination of TP, we followed the DE-UZ 219 test guideline. In a second round we repeated the tests with all printers adjusted to exactly the same extruder temperatures, i.e., to TE=230°C for ABS and TE=210°C for PLA. All measurements were conducted in a 1 m³ emission test chamber. Particle emissions in the size range between 4 nm and 20 μm were detected. Printing on three different printer models without temperature adjustment resulted for each of the investigated feedstocks in a variation in TP of around two orders of magnitude. After temperature adjustment, this was substantially reduced to approx. one order of magnitude and hence minimizes the bias of printer hardware on the emissions. Our findings suggest that adjustment of the extruder temperature should be mandatory in emission testing standards. It also poses a more accurate benchmark and provides more reliable emission data for evaluation of indoor air quality or for health risk assessments. In addition, a proper temperature setting is in the interest of the user. Some commercial FFF printers may have a higher actual extruder temperature than displayed and unintended overheating may not only impair the print quality but may cause unnecessarily increased exposure to particle emissions.
Estrogens are endocrine disrupting chemicals and of high concerns due to demonstrated harmful effects on the environment and low effect levels. For monitoring and risk assessment, several estrogens were included in the "watch list" of the EU Water Framework Directive which sets very low environmental quality standard (EQS) levels for Estrone (E1) and 17β-Estradiol (E2) of 0.4 ng L−1 and for 17α-Ethinylestradiol (EE2) of 0.035 ng L−1 requiring sensitive detection methods, as well as extensive sample preparation. A sensitive, derivatization-free, isotope dilution calibration HPLC-MS/MS method for a panel of 5 selected estrogens (including the 3 estrogens of the EU WFD watchlist), and a procedure for the reproducible preparation of a representative whole water matrix including mineral water, humic acids and solid particulate matter are presented. These are used in a diligent comparison of classical solid phase extraction (SPE) on hydrophilic-lipophilic balanced (HLB) phase to SPE on an estrogen-specific molecularly imprinted polymer phase (MISPE) for ultra-trace levels of the analytes (1–10 ng L−1). Additionally, a two-step procedure combining HLB SPE disks followed by MISPE is evaluated. The tow-step procedure provides superior enrichment, matrix removal and sample throughput while maintaining comparable recovery rates to simple cartridge SPE. Estimated method quantification limits (MQLs) range from 0.109–0.184 ng L−1 and thus meet EQS-levels for E1 and E2, but not EE2. The representative whole water matrix provides a reproducible comparison of sample preparation methods and lays the foundation for a certified reference material for estrogen analysis. The presented method will serve as the basis for an extended validation study to assess its use for estrogen monitoring in the environment.
EDC WFD project to deliver reliable measurements of estrogens for better monitoring surveys and risk assessments.
Collaboration between National Metrology Institutes and advanced research institutes from 6 European countries A Balance of expertise: development and certification of RM, proficiency tests / interlaboratory comparison design, method development and validation, standardisation A 3 years project: September 2019- August 2022
Strong engagement with stakeholders (Advisory Group)
Metrology for Monitoring of Endocrine Disrupting Chemicals Under the EU Water Framework Directive
(2021)
Monitoring programs should generate high-quality data on the concentrations of substances and other pollutants in the aquatic environment to enable reliable risk assessment. Furthermore, the need for comparability over space and time is critical for analysis of trends and evaluation of restoration of natural environment. Additionally, research work and exercises at the European level have highlighted that reliable measurements of estrogenic substances especially three estrogens of the first watch list (17-beta-estradiol (17βE2), 17-alpha-ethinylestradiol (EE2), and estrone (E1))at the PNEC level are still challenging to achieve.With respects to their physicochemical properties, the 3 substances have the potential to disseminate within aquatic environments, to enter the food chain and to bioaccumulate, Chemical monitoring relies on a succession of actions: sampling, storage and preservation of representative samples; pre-treatment of a sample portion for quantification, calibration, final determination, calculation of results, uncertainty estimation and final expression of results. Throughout this chain of operations, the guarantee of the stability of the analyte is a key issue that has to be addressed to correctly qualify and discuss monitoring data.
The project EDC-WFD aims to develop traceable analytical methods for determining endocrine disrupting compounds and their effects, with a specific focus on three estrogens of the first watch. Environmental quality standards (EQS) for these compounds are at the ultra-trace level (EQS EE2 = 35 pg/L, EQS E2 = 400 pg/L, EQS E1 = 3600 pg/L) and pose a significant challenge to analytical methods. Estrogens 17-alpha-estradiol (17αE2) and estriol (E3) will be included to demonstrate the reliability of the developed methods and to support the requirements of Directive 2013/39/EC, Directive 2009/90/EC and Commission Implementation Decision (EU) 2018/840, hence improving the comparability and compatibility of measurement results within Europe. The project will also evaluate the interaction and partitioning of the 5 estrogenic compounds between water samples and suspended particulate matter (SPM) and the capability of developed methods to address the different fractions of matrix (whole water and dissolved concentrations of estrogens).
This contribution will present the objectives and methods applied within the EDC-WFD project that could support a better comprehension of the biogeochemical cycle of selected estrogenic substances in aquatic system
Funding: This project (18NMR01) has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme
Monitoring programs should generate high-quality data on the concentrations of substances and other pollutants in the aquatic environment to enable reliable risk assessment. Furthermore, the need for comparability over space and time is critical for analysis of trends and evaluation of restoration of natural environment. Additionally, research work and exercises at the European level have highlighted that reliable measurements of estrogenic substances at the PNEC level are still challenging to achieve.
The project EDC-WFD Metrology for monitoring endocrine disrupting compounds under the EU Water Framework Directive aims to develop traceable analytical methods for determining endocrine disrupting compounds and their effects, with a specific focus on three estrogens of the first watch list (17-beta-estradiol (17βE2), 17-alpha-ethinylestradiol (EE2), and estrone (E1)). Estrogens 17-alpha-estradiol (17αE2) and estriol (E3) will be included to demonstrate the reliability of the developed methods and to support the requirements of Directive 2013/39/EC, Directive 2009/90/EC and Commission Implementation Decision (EU) 2018/840, hence improving the comparability and compatibility of measurement results within Europe. During the EDC-WFD project four selected effect-based methods (EBM) will be deeply investigated in order to improve their rationale use and their support in water quality assessment. In particular, the EBM sensitivity, specificity and accuracy on reference materials with single or mixture solutions of the five substances at a concentration of EQS values will be explored.
This project (18NMR01) has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme.
Polycyclic aromatic hydrocarbons (PAH) can contaminate plastic and rubber parts of consumer products including toys. PAH are present as impurities in some of the raw materials used for production of such articles, particularly in extender oils and in carbon black. Because PAH have negative effects on health (e.g. carcinogenic), standard methods have been developed in several countries to control PAH in consumer/toy products, mainly based on gas-chromatography mass-spectrometry (GC-MS).
To protect consumers from hazards of PAH, national regulations and maximum levels are already in force, for example in Germany. Recently, maximum levels for 8 PAH compounds (benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[e]pyrene, benzo[a]pyrene and dibenz[a,h]anthracene) have been established by EC-regulation 1272/2013. This resulted in an urgent need for certified reference materials (CRM) to meet the requirements of the EC-regulation (1 mg/kg for each PAH compound in consumer products and 0.5 mg/kg in toys, respectively).
In 2016 BAM started a project to certify the PAH mass fractions in a toy CRM to fill the current gap of available reference materials. Several different toys from retailers were screened to obtain a real-life material representing PAH mass fractions in the range of the EC-maximum level. The finally selected material (rubber balls for children) was prepared and characterized with respect to homogeneity and stability of 18 PAH. The extension to other health-relevant PAH compounds, e.g. indeno[1,2,3-cd]pyrene and benzo[ghi]perylene, will increase the applicability of the CRM for costumers, e.g. from industry, conformity assessment bodies and private testing laboratories.
The poster will present the current status of the ongoing CRM project including preparation of the candidate material and results from homogeneity and stability studies. In addition, first results of a joint German-Chinese interlaboratory comparison study will be shown.
Per- and polyfluoroalkyl substances (PFAS) have received global public attention because of their wide distribution in aquatic environments and potential adverse effects to humans and wildlife. Due to the lack of analytical standards and the enormous numbers of these compounds, current target-based methods (e.g., LC-MS/MS) are not suitable for the analysis of new/unknown PFAS and transformation products. Therefore, PFAS sum parameter analysis is becoming increasingly important. For PFAS determination of surface waters, solid phase extraction (SPE) is commonly implemented for clean-up and pre-concentration of samples.
Thus, within this work, single-layer SPE methods (based on Strata™-X, Strata™-X-AW, Strata™-NH2 and Oasis-HLB) were investigated for maximum PFAS coverage utilizing extractable organically bound fluorine (EOF) analysis. Thereby, the optimization procedure relied on the analysis of 3 surface water samples in Berlin, Germany, which were affected by the effluent discharge of wastewater treatment plants. To analyse the SPE elution profiles for EOF and inorganic fluorine, high resolution-continuum source-graphite furnace molecular absorption spectroscopy (HR-CS-GFMAS) and ion chromatography (IC) were used, respectively.
Highest EOF concentrations were achieved by using Strata-X/Strata-XAW as SPE sorbents and methanol as eluent. Furthermore, combinations of the most promising SPE sorbents were selected (X/XAW, XAW/X, HLB/X and WAX/GCB) to extract a wider range of PFASs. By comparing multi-layer SPE methods, lower EOF concentrations were obtained for all investigated combination phases compared to the analysed single phases. For the commercially available combination phase Strata-PFAS (WAX/GCB) for all three river water samples, lower EOF concentrations (1.5 times lower) were determined compared to Strata-X.
The results have shown that single-layer SPE systems are currently superior compared to combination phases for PFAS sum parameter analysis. The multi-layer SPE methods need further optimization regarding appropriate sorbent combinations, loading volumes and elution conditions. The developed single-layer SPE methods can help to elucidate pollutions hotspots and discharge routes.
Portable, antikörperbasierte Analysenverfahren für die Schadstofferfassung im Wasserkreislauf
(2021)
Die Wasseranalytik wird bestimmt von zwei Hauptbedarfen, einerseits der Erfassung der Gewässergüte und Grundwassergüte als Basis für die Bereitstellung einwandfreien Trinkwassers und zum anderen des Monitorings der Wasserqualität in den Prozessen der Wasseraufbereitung und der Abwasserreinigung. Für beide Anwendungsbereiche ist eine laborbasierte Analytik eher hinderlich, werden die Analysenergebnisse doch eigentlich vor Ort benötigt, um etwa Beprobungskampagnen rasch anpassen zu können. Des Weiteren werden die Daten auch schnell benötigt, um zeitnah in die technischen Prozesse einzugreifen. Organische Kontaminanten werden meist über chromatographische Verfahren, häufig gekoppelt mit einer massenspektrometrischen Detektion, in instrumentellen Labormethoden erfasst, und die hochauflösende Massenspektrometrie und die Non-target-Analytik haben viel zum Wissen über das Vorkommen, insbesondere von sogenannten „Emerging Contaminants“, beigetragen, sowie zum Verständnis der beteiligten Eintragspfade und Abbauwege. Moderne, portable Analysenmethoden und insbesondere Sensoren werden zukünftig aber ihren Platz in der Schadstofferfassung im Wasserkreislauf einnehmen. Dies gilt insbesondere für antikörperbasierte Analysenverfahren, da erst diese oft die nötige Selektivität und Sensitivität in die Detektionsmethoden einbringen.
Portable, antikörperbasierte Analysenverfahren für die Schadstofferfassung im Wasserkreislauf
(2021)
Die Wasseranalytik wird bestimmt von zwei Hauptbedarfen, einerseits der Erfassung der Gewässergüte und Grundwassergüte als Basis für die Bereitstellung einwandfrei-en Trinkwassers und zum anderen des Monitorings der Wasserqualität in den Prozes-sen der Wasseraufbereitung und der Abwasserreinigung. Für beide Anwendungsbe-reiche ist eine laborbasierte Analytik eher hinderlich, werden die Analysenergebnisse doch eigentlich vor Ort benötigt, um etwa Beprobungskampagnen rasch anpassen zu können. Desweiteren werden die Daten auch schnell benötigt, um zeitnah in die technischen Prozesse einzugreifen. Organische Kontaminanten werden meist über chromatographische Verfahren, häufig gekoppelt mit einer massenspektrometrischen Detektion, in instrumentelle Labormethoden erfasst und die hochauflösende Massen-spektrometrie und die Non-target-Analytik haben viel zum Wissen über das Vorkom-men, insbesondere von sog. „emerging contaminants“, beigetragen, sowie zum Ver-ständnis der beteiligten Eintragspfade und Abbauwege. Moderne, portable Analy-senmethoden und insbesondere Sensoren werden zukünftig aber ihren Platz in der Schadstofferfassung im Wasserkreislauf einnehmen. Dies gilt insbesondere für anti-körperbasierte Analysenverfahren, da erst diese oft die nötige Selektivität und Sensitivität in die Detektionsmethoden einbringen.
A vast number of emerging pollutants has been detected in the environment over the last decades. Analytical methods suitable for trace analysis are needed that are desirably also fast, inexpensive and, if possible, robust and portable. Immunoanalytical, i.e. antibody-based, methods which are available in a broad range of formats, can be profitably used here to analyse for the distribution and the trends of concentration levels of contaminants in the environment. Some of these formats are single-analyte but high-throughput methods. In order to use them wisely, indicator substances, sometimes called anthropogenic markers, should be selected and used in screening approaches. Other methods are suitable to be performed on portable instrumentation in the field (on-site) or in facilities such as wastewater treatment plants for on-line monitoring. Furthermore, there are array technologies that allow for parallel (multiplex) analysis of several analytes of interest.
The microtiter-plate based ELISA (Enzyme-linked Immunosorbent Assay) is the method of choice for the analysis of a large number of samples [1]. ELISAs are available to monitor for anthropogenic markers such as the antiepileptic carbamazepine, the analgesic diclofenac, the antihistaminic cetirizine, the steroid hormone estrone, the antimicrobial sulfamethoxazole, the stimulants caffeine and cocaine, the priority pollutant bisphenol A, and the bile acid isolithocholic acid. For on-site screening and monitoring, simpler formats, like mix-and-read assays, e.g. the Fluorescence Polarization Immunoassay (FPIA) [2] or Lateral-flow Immunoassays (LFIA) [3] are more suitable tools, the latter based on dipsticks or cassettes, that is why they are also called pregnancy test-like assays. The suitability of multi-analyte formats such as immunomicroarrays depends on the choice of a signal-producing system that provides small uncertainties and good reproducibility of the measurements. Bead-based (“suspension”) arrays read out in flow cytometers are a powerful platform for multiplex assays [4]. Electrochemical formats run on portable devices provide additional advantages as no light source is required. They are most promising for stand-alone analysers and biosensors
A vast number of emerging pollutants is being detected in the environment. Another lingering problem are health-threatening contaminants, such as mycotoxins, that deteriorate food and feed.
Analytical methods, suitable for trace analysis, are needed that are desirably also fast, inexpensive and, if possible, robust, and portable. Immunoanalytical, i.e., anti-body-based technologies, which are available in a broad range of formats, can be profitably used here to analyze for the distribution and the concentration trends of contaminants.
Some of these formats are single-analyte but high-throughput methods. To use them wisely, indicator substances or sum parameters must be established to be used in screening approaches. Other methods are suitable to be performed on portable in-strumentation in the field (on-site), more precisely at the point-of-need. Furthermore, there are array technologies that allow for parallel analysis of several analytes of interest (multiplexing). The talk reports on methods and data for compounds con-sidered as anthropogenic contamination markers (the antiepileptic carbamazepine, the analgesic diclofenac, the anti-histaminic cetirizine, the steroid hormone estrone, the antimicrobial amoxicillin, the stimulants caffeine and cocaine, the endocrine disruptor bisphenol A, and a bile acid). Some work on mycotoxins (ochratoxin A and ergot alkaloids) is also presented. It is demonstrated that antibody-based technolo-gies have a huge potential to gain analytical insights at the point-of-need.
Antibody-based analytical techniques have gained increasing importance in environmental analysis. Rapid assays, portable devices and formats that require a limited number of steps have a high potential for on-site analysis in outdoor environments or in environmentally relevant facilities such as wastewater treatment plants. Many of these methods have become more sensitive and more versatile due to new, advanced materials, such as novel particles, specifically prepared surfaces, new labels, specifically coated electrodes etc. The talk shows some of our works in this context.
A vast number of emerging pollutants is being detected in the environment. Another lingering problem are health-threatening contaminants, such as mycotoxins, that deteriorate food and feed.
Analytical methods, suitable for trace analysis, are needed that are desirably also fast, inexpensive and, if possible, robust, and portable. Immunoanalytical, i.e., antibody-based methods, which are available in a broad range of formats, can be profitably used here to analyze for the distribution and the concen-tration trends of contaminants.
Some of these formats are single-analyte but high-throughput methods. To use them wisely, indicator substances or sum parameters are being established and used in screening approaches. Other methods are suitable to be performed on portable instrumentation in the field (on-site), more precisely at the point-of-need. Furthermore, there are array technologies that allow for parallel analysis of several analytes of interest (multiplexing).
The talk reports on methods and data for compounds considered as anthropogenic contamination markers (the antiepileptic carbamazepine, the analgesic diclofenac, the anti-histaminic cetirizine, the steroid hormone estrone, the antimicrobial amoxicillin, the stimulants caffeine and cocaine, the endo-crine disruptor bisphenol A, and a bile acid). Some work on mycotoxins (ochratoxin A and ergot alka-loids) is also presented. It is demonstrated that antibody-based approaches have a huge potential to gain analytical insights at the point-of-need.
A vast number of emerging pollutants is being detected in the environment. Another lingering problem are health-threatening contaminants, such as mycotoxins, that deteriorate food and feed, and the pathogens themselves. Analytical methods, suitable for trace analysis, are needed that are desirably also fast, inexpensive and, if possible, robust and portable. It is set out, how immunoana-lytical, i.e., antibody-based methods, which are elaborated in a broad range of formats, can be profitably used to gain insights on the distribution and concentration trends of the target analytes at the point-of-need.
Immunoanalytical Techniques, i.e., antibody-based analytical methods, have been used for decades in clinical diagnostics. What makes them attractive for other fields of application is their short time-to-result and high sensitivity. Microplate-based assays such as ELISA have been adopted early in environmental and food analysis. Yet, to make immunoassays even faster, more sensitive, robust, and, most desirable, portable, advanced materials, sometimes developed for other purposes, can be profitably used to achieve these goals. Materials can be novel labels, e.g., chemical or particle labels, such as fluorophores or nanoparticles. Carrier particles, such as magnetic or polymer beads, make it possible to adopt the assays to meso- or microfluidic set-ups and encoding them opens the path to multiplex analysis. Specialty electrodes can enable for higher sensitivity in electrochemical detection. All this broadens the scope of application and lowers effort and cost for analysis at the point-of-need.
In urban waters, a multitude of organic micropollutants, often termed emerging pollutants, has been found over the last decades. Analytical methods suitable for trace analysis are needed that are desirably also fast, inexpensive and, if possible, robust and portable. Immunoanalytical, i.e., antibody-based, methods which are available in a broad range of formats, can be profitably used here to screen for the distribution and to monitor the trends of concentration levels of contaminants of emerging concern in the environment. Some of these formats are single-analyte but high-throughput methods. To use them wisely, indicator substances, sometimes called anthropogenic markers, should be selected and used in screening approaches, i.e., as indicators for contamination and the pre-selection of samples at which to have a closer look by multiplex methods like LC-MS/MS. Other methods are suitable to be performed on portable instrumentation in the field (on-site) or in facilities such as wastewater treatment plants for on-line monitoring of the treatment and elimination process. Furthermore, array technologies have been established that allow for parallel (multiplex) analysis of several analytes of interest.
The microtiter-plate based ELISA (Enzyme-linked Immunosorbent Assay) is the method of choice for the analysis of a large number of samples [1]. ELISAs are available to monitor for anthropogenic markers such as the antiepileptic carbamazepine, the analgesic diclofenac, the antihistaminic cetirizine, the steroid hormone estrone, the antimicrobial sulfamethoxazole, psychoactive caffeine and cocaine, the priority pollutant bisphenol A, and the bile acid isolithocholic acid. For on-site screening and monitoring, simpler formats, like mix-and-read assays, e.g., the Fluorescence Polarization Immunoassay (FPIA) [2] or Lateral-flow Immunoassays (LFIA) [3] are more suitable tools, the latter based on dipsticks or little cassettes, with which users have become very familiar during the COVID-19 pandemic via rapid antigen tests. The suitability of multi-analyte formats such as immunomicroarrays depends on the choice of a signal-producing system that provides small uncertainties and good reproducibility of the measurements. Bead-based (“suspension”) arrays, read out in flow cytometers, are a powerful platform for multiplex assays [4]. Electrochemical formats, run on portable devices, provide additional advantages as no light source is required. They are most promising for stand-alone analysers and biosensors [5].
The speed, low cost and on-site capabilities of these methods allow to gather a lot more data on anthropogenic compounds which enables to quantify inputs, differences in degradation power of elimination processes, dilution phenomena and a more precise image of individual water cycles which is demonstrated by several examples.
Analytical methods based on the selectivity of antibodies, often called immunoassays, are a back-bone of clinical laboratory diagnostics. To bring them to the field, i.e., to make immunoanalytical methods portable, hopefully even faster, more sensitive, and robust, advanced materials are re-quired. Materials can be novel labels, e.g., chemical or particle labels, such as fluorophores or na-noparticles. Carrier particles, such as magnetic or polymer beads, make it possible to adopt the as-says to meso- or microfluidic set-ups and encoding them opens the path to multiplex analysis. Spe-cialty electrodes can enable for higher sensitivity in electrochemical detection. Without research into better materials, efforts to bring analysis to the point-of-need will not bear fruit.
Vortrag zum Kick-off des Projektes.
Ziel des Projektes ist es, die Eignung der Bestimmung eines oder mehrerer der genannten anthropogenen Marker im Abwasser zur Volumenkorrektur („Kalibration“) im SARS-CoV-2-Monitoring von Abwässern auf der Basis eines von der BAM zu erhebenden Messdatensatzes zu evaluieren.
ESI-CorA ist ein nationales Verbundprojekt mit dem Ziel des Nachweises von SARS-CoV-2 im Abwasser.
Das UBA hat als Teilprojekt das Projekt MARKERIA (VH1802) an die BAM vergeben.
Ziel des Projektes ist es, die Eignung der Bestimmung eines oder mehrerer der genannten anthropogenen Marker im Abwasser zur Volumenkorrektur („Kalibration“) im SARS-CoV-2-Monitoring von Abwässern auf der Basis eines von der BAM zu erhebenden Messdatensatzes zu evaluieren.
1. Projektreffen mit dem Umweltbundesamt für das Projekt MARKERIA (VH1802).
Ziel des Projektes ist es, die Eignung der Bestimmung eines oder mehrerer der genannten anthropogenen Marker im Abwasser zur Volumenkorrektur („Kalibration“) im SARS-CoV-2-Monitoring von Abwässern auf der Basis eines von der BAM zu erhebenden Messdatensatzes zu evaluieren.
2. Projekttreffen mit dem Umweltbundesamt zum Projekt MARKERIA (VH1802).
Ziel des Projektes ist es, die Eignung der Bestimmung eines oder mehrerer der genannten anthropogenen Marker im Abwasser zur Volumenkorrektur („Kalibration“) im SARS-CoV-2-Monitoring von Abwässern auf der Basis eines von der BAM zu erhebenden Messdatensatzes zu evaluieren.
The talk introduces the technique of LC-ELISA: fractionating pre-concentrated water samples, analyzing them for containing compounds that bind to hapten-selective antibodies followed by high-Resolution mass spectrometry non-target analysis of "positive" fractions for Transformation products of emerging organic contaminants.
A vast number of emerging pollutants has been detected in the environment over the last decades. Analytical methods suitable for trace analysis are needed that are desirably also fast, inexpensive and, if possible, robust and portable. Immunoanalytical methods which are available in a broad range of formats, can be profitably used here to analyze for the distribution and the trends of concentration levels of contaminants in the environment. Some of these formats are single-analyte but high-throughput methods. In order to use them wisely, indicator substances, sometimes called anthropogenic markers, should be selected and used in screening approaches. Other methods are suitable to be performed on portable instrumentation in the field (on-site) or in facilities such as wastewater treatment plants for on-line monitoring. Furthermore, there are the socalled array technologies that allow for parallel analysis of several analytes of interest (multiplexing). The microtiter-plate based ELISA (Enzyme-linked Immunosorbent Assay) is the method of choice for the analysis of a large number of samples [1]. ELISA screening data for anthropogenic markers such as the antiepileptic carbamazepine, the analgesic diclofenac, the anti-histaminic cetirizine, the steroid hormone estrone, the antimicrobial sulfamethoxazole, the stimulants caffeine and cocaine, the priority pollutant bisphenol A, and the bile acid isolithocholic acid [2] are presented. For on-site screening and monitoring, simpler formats, like mix-and-read assays, e.g. the Fluorescence Polarization Immunoassay (FPIA) or Lateral-flow Immunoassays (LFIA) are more suitable tools. Electrochemical formats run on portable devices provide additional advantages as no light source is required. Some examples are presented and discussed. The suitability of multi-analyte formats such as immunomicroarrays depends on the choice of a signal-producing system that provides small uncertainties and good reproducibility of the measurements. Biochip (“flat”) arrays read out on slide scanners and bead-based (“suspension”) arrays read out in flow cytometers are two options and show their distinct pros and cons. Altogether these approaches show the great potential immunoanalytical methods provide for the screening for environmental contaminants in the aquatic environment.
Der Vortrag beschreibt den Stand der Arbeiten an der BAM, Fachbereich Umweltanalytik zur Entwicklung von Sensoren für die Wasseranalytik. Er stellt die bisherigen Arbeiten da, die ausgehend von ELISAs, zunehmend portable Plattformen wie FPIA und LFIA umfassen. Beas-based Formate werden von mikrotiterplatten-basierten Techniken auf mikrofluidische Lab-on-Chip-Systeme übertragen, die bei geeigneter Miniaturisierung und Automatisierung als Sensorsysteme angesehen werden können. Der Vortrag endet mit einem Blick auf ein laufendes Monitoring-Projekt von anthropogenen Markern in Abwasser und charakterisiert die Treiber, die die Entwicklung von Sensoren für die Wasseranalytik in den letzten Jahren vorantreiben.
Im Vorhaben „MARKERIA - Bestimmung von anthropogenen Markerkonzentrationen für die SARS-CoV-2 Quantifizierung mittels eines Hochdurchsatzverfahrens (ELISA)“ geht es um die Bestimmung von Carbamazepin, Diclofenac, Koffein und einer endogenen Gallensäure als potentielle Marker für die Kalibrierung der SARS-CoV-2 Quantifizierung im Abwasser. Der Vortrag wurde gehalten im Rahmen der 22. Sitzung des Begleitkreises des übergeordneten Projektes ESI-CorA. Er gab den Projektstand wieder, den die BAM bis dahin erzielt hatte. Die Marker waren in sämtlichen untersuchten Abwasser-Zulaufproben enthalten und zeigten spezifische Trends. Weitere Korrelationen müsse die weitergehende Datenauswertung ergeben.A
Diclofenac (DCF) is a widely used drug against fever, inflammation, pain, and rheumatic diseases. An average of 70 % of the ingested diclofenac is excreted in the urine. Thus, 63 tons per year are introduced into the water cycle in Germany. Due to insufficient removal of diclofenac in wastewater treatment plants, residues of diclofenac can be found in surface water and sometimes in drinking water. In order to establish an immunoassay, an anti-DCF antibody was required. Some antibody developments have been reported, based on an immunogen resulting from direct coupling of diclofenac to proteins via the carboxylic function. Finally, we used a monoclonal antibody, clone F01G21.
Organotin compounds (OTCs) have been widely used in anti-fouling paints, pesticide formulations, and as stabilizers in polyvinyl chloride over the past century. In marine ecosystems, OTCs can cause severe damage to biodiversity, leading up to the extinction of vulnerable species. Due to the extensive use of tributyltin (TBT) as a biocide on ship hulls, it has been considered one of the most hazardous substances intentionally introduced into the aquatic environment. This resulted in a global ban on TBT-containing products in the 2000s. However, recent studies indicate the emerging presence of organotin pollutants.
OTCs are known to persist and accumulate in marine sediments, posing a long-term threat to the environment. These harmful substances can be set free and dispersed even after several decades. Therefore, analyzing sediment probes is imperative for a thorough monitoring of pollution. However, species-specific analysis of OTCs at required concentration levels in complex environmental matrices remains challenging. Chromatographic systems are commonly used for their analysis, but the required sample preparation is time-consuming and prone to contamination and analyte loss. The coupling of electrothermal vaporization and inductively coupled plasma-mass spectrometry (ETV/ICP-MS) demonstrates high potential as a rapid, convenient, and chemical-saving scanning tool for environmental samples.
This method enables the direct on-line fractionation of organic compounds from an inorganic fraction and provides element-specific detection at ultra-trace levels without complex sample preparation. Since OTCs are generally more toxic than ionic or elemental tin, analyzing them as a sum parameter is advantageous. Additionally, the determination of both organic and inorganic tin, rather than just organic tin, reveals valuable information about the fate of OTCs. The main challenge in obtaining accurate quantitative data using direct solid sampling techniques like as ETV/ICP-MS is applying a suitable calibration strategy. Our isotope dilution approach overcomes matrix effects in ETV/ICP-MS analysis and is compatible with commercial systems.
Neuartige Materialien, die bekannte (Werk-)Stoffe mit neuen Funktionalitäten ausstatten, spielen eine zunehmend wichtige Rolle im Bereich der Materialforschung und -prüfung. Das Spektrum neuartiger Materialien reicht von der gezielten Oberflächenfunktionalisierung und -strukturierung makroskopischer Materialien, dünnen Beschichtungen bis hin zu mikro- und nanoskaligen Kompositmaterialien und funktionalen Materialien an der Schnittstelle zur Biologie, Biotechnologie, nachhaltige Energiespeicherung und Sensorik. Dabei bieten neuartige Materialien die Chance, Werkstoffe und Produkte mit erweiterter oder verbesserter Funktionalität zu erhalten und Sicherheit bereits im Designprozess zu berücksichtigen. Durch dieses breite Anwendungsspektrum und die Herausforderungen, die solche Materialien für die Sicherheit in Chemie und Technik mit sich bringen, sind diese in allen Themenfeldern der BAM repräsentiert (Material, Analytical Sciences, Energie, Infrastruktur und Umwelt).
Die Aufgaben der BAM erstrecken sich dabei von der Herstellung von Referenzmaterialien für Industrie, Forschung und Regulation, über die Erstellung von standardisierten Referenzverfahren für nachhaltige Messungen im Umwelt- und Lebenswissenschaftsbereich bis hin zur Bereitstellung von belastbaren und zitierbaren Referenzdaten. Durch die genaue Charakterisierung neuartiger Materialien können potentiell problematische Substanzen identifiziert und deren Risiken besser abgeschätzt werden. In diesem Beitrag werden einige aktuelle Beispiele aus diesen Bereichen vorgestellt.
In particular, the rapid development of lateral flow assays as indispensable tools for everyone to contain the SARS-CoV-2 pandemic has fuelled the global demand for analytical tests that can be used outside dedicated laboratories. In addition to their use in medical diagnostics, rapid tests and assays have become increasingly important in various fields such as food safety, security, forensics, and environmental management. The advantage is obvious: taking the assay directly to the sample minimizes the time between suspicion and decision-making, allowing faster action. Especially today, when mobile communication devices with powerful computing capabilities and built-in cameras are ubiquitous, more people than ever before around the world have the basic skills to operate a powerful detector at their fingertips. This sets the stage for a much wider use of analytical measurements in terms of prognosis and prevention, enabling professional laypersons in particular.
However, current strip-based systems are primarily focused on single parameter analysis, whether it is SARS-CoV-2 biomarkers, blood glucose levels, or lead concentrations in water samples. Industrial applications of such methods also often still rely on single-parameter assays, requiring multiple runs even for a limited number of key parameters. Overcoming these limitations depends on developing low-number multiplexing strategies that ensure robustness, reliability, speed, ease of use, and sensitivity.
This lecture will give an overview of several generic approaches developed in recent years to address these challenges. It will highlight how the synergy of supramolecular (bio)chemistry, luminescence detection, hybrid (nano)materials and device miniaturization can result in powerful (bio)analytical assays that can be used at a point-of-need.1-5 Selected examples will introduce key aspects of such systems that include tailored signaling mechanisms and recognition elements, materials functionalization and device integration, including hybrid nanomaterials, gated indicator release systems, strip modification, and smartphone-based analysis.
•Overview of expertise of division Biophotonics
•Functional molecular and nanoscale luminescent reporters, probes, and
sensors including design principles available from division Biophotonics
•Examples for pH and O2 responsive molecular probes and particle sensors
•Surface group quantification Analytical methods and cleavable probes
•Concepts & standards for the validation and traceability of optical measurements
Photoluminescence applications in the life and material sciences require bright molecular and nanocrystalline emitters, stimuli-responsive optical probes, signal enhancement, multiplexing, and barcoding strategies and traceable methods to quantify the signal-relevant optical properties of luminescent materials at the ensemble and single molecule/particle level. In this context, current research at Division Biophotonics of BAM is presented ranging from dye and nanocrystal photophysics, absolute measurements of photoluminescence quantum yields in the UV/vis/NIR/SWIR, lifetime multiplexing, and the development of different types of fluorescence standards for validating optical-spectroscopic measurements.
Aiming at the development of a non-destructive optical measurement methods for the characterization of nano-sized airborne particulate pollutants we performed fluorescence spectroscopic investigations of their relevant emission properties. Here, we present first results from studies of soot particles from synthetic aerosols deposited on PTFE membranes.
The rational synthesis and use of nanomaterials require the characterization of many different properties, ranging from particle size and size distribution over surface chemistry to more applicationrelevant features like optical, electrochemical, and magnetic properties. In the following, several methods for the characterization of functional groups on nanomaterials, like polymer and silica nanoparticles, semiconductor quantum dots, and lanthanide-based upconversion nanocrystals are presented. Additionally, procedures for the measurement of the key spectroscopic performance parameters of nanomaterials with linear and nonlinear photoluminescence, such as the photoluminescence quantum yield, are presented for the UV/vis/NIR/SWIR.
The comparison of different emitter classes and the rational design of the next generation of molecular and nanoscale reporters require accurate and quantitative photo-luminescence measurements. This is of special importance for all photoluminescence applications in the life and material sciences and nanobiophotonics. In the following, procedures for the determination of the spectroscopic key parameter photoluminescence quantum yield, i.e., the number of emitted per absorbed photons, in the UV/vis/NIR/SWIR are presented including pitfalls and achievable uncertainties and material-specific effects related to certain emitter classes are addressed.
Luminescent nanocrystals like core/shell semiconductor quantum dots and lanthanide doped nanophosphors as well as gold nanoclusters with emission in the visible (vis) and particularly in the near infrared (NIR) and short wavelength infrared (SWIR) region have been increasingly used as reporters in the life sciences and for bioimaging studies in the last years. This has led to sophisticated core-shell particle architectures of different chemical composition utilizing semiconductor quantum dots and lanthanide-based nanocrystals and initiated the design of gold nanoclusters with different ligands. In addition, this led to an increasing number of quantitative spectroscopic studies focusing on the key performance parameter photoluminescence quantum yield to identify optimum particle structures. In the following, an overview of different classes of nanocrystalline emitters and their photophysics is provided and examples for the absolute characterization of the photoluminescence properties of these different vis/NIR/SWIR emitters are shown including excitation power density-dependent studies on the ensemble and single particle level. Also, the impact of such measurements on a profound mechanistic understanding of the underlying nonradiative deactivation pathways is highlighted as required for reporter design.
Mycotoxins are toxic secondary metabolites produced by filamentous fungi. The contamination of mycotoxins in food and feed products has been recognized to be an important safety issue for human and animal health. In the context of food safety, medical herbs nowadays are also considered as potential source of mycotoxins. Considering that mycotoxins are generally stable compounds and could not be destroyed completely during food-processing operations, prevention of contamination is identified as main issue.
Currently, biochemical, and immunochemical methods based on the use of antibodies as a specific recognition bioreagents are increasingly found to be applied in screening. Along with good common enzyme linked immunosorbent assay (ELISA), more and more widely used method is fluorescence polarization immunoassay (FPIA). These methods help to monitor of many toxic substances in large number of samples and carried out quickly, easily, cheaply, and give good results in quantifying the one or more substances. That is why the use of immunochemical methods of analysis, such as ELISA and FPIA, is the most promising for solving this problem.
Thus, the aim of our work is to optimize the determination of mycotoxins by ELISA and FPIA in medical herbs. We selected antibodies and a tracer for the FPIA, then we constructed obtained a calibration curve and determined the sensitivity of this method for the samples in aqueous media. Then, the optimal sample preparation was elaborated: for spiked nuts samples were selected and prepared and a calibration curve was obtained with respect to the matrix effect. After that, the analysis of spiked nuts samples was performed by ELISA and FPIA and the sensitivity of both methods was compared.
Background. Aflatoxin B1 (AFB1) is a toxic low-molecular-weight secondary fungal metabolite produced mainly by Aspergillus flavus and Aspergillus parasiticus not only at pre-harvest time but also at post-harvest stages including storage. AFB1 was classified as a Group I carcinogen by the World Health Organization for Research on Cancer in 1993. AFB1 is able to naturally contaminate medicinal plants and therefore causing serious health issues for humans consuming the related medicine. This study aimed to develop an efficient fluorescence polarization immunoassay (FPIA) and for the first time a rapid (5-10 min), low-cost, and simple membrane-based flow-through immunoassay (MBA) for determination of AFB1 in medical herbs based on a monoclonal antibody.
Methods. Two different techniques for AFB1detection in medical herbs (Herba Orígani vulgáris, Folia Urticae, Fructus Rubi idaei) were developed and compared, namely an easy-to-use semi-quantitative flow-through membrane-based enzyme immunoassay (MBA), and a homogeneous method which needs no separation or washing steps (assay time 10 min), a quantitative fluorescence polarization immunoassay (FPIA).
Results. A cut-off level of the developed MBA can vary wide from 0.8 ppb to 1 ppb. The FPIA method showed a linear working range of 8.6 ppb to 64 ppb, IC50 of FPIA is 24 ppb. The results were in good correlation with the ELISA results (IC50 = 0.1 ppb). LC–MS/MS was used to confirm the results, too.
Conclusion. MBA can be used for a quick on-site AFB1 detection in medical herbs (Herba Orígani vulgáris (Oríganum vulgáre), Folia Urticae (Urtíca dióica), Fructus Rubi idaei (Rúbus idáeus)), the developed test does not require special equipment and is not time-consuming (5-10min), includes several simple steps and can be performed directly on-site. The major advantages of the developed FPIA are its simplicity and suitability for a rapid screening of a large number of samples.
Bisphenol A (BPA) is a chemical that has been used in the production of plastics for more than 40 years. BPA released from bottles made of polycarbonates has been identified as a potential endocrine disrupting substance. Comprehensive research has been undertaken to test and verify its effect on animals and human beings.
Many methods have been proposed for the determination of BPA, in particular, gas and liquid chromatography. The main disadvantages of such approaches are the high cost of the equipment, the significant duration of an analysis, and difficulties in screening a large number of samples. Lateral Flow ImmunoAssay (LFIA) attributes are high throughput, high specificity and sensitivity, as well as low cost and simplicity.
An LFIA test strip was developed. This LFIA is based on anti-BPA antibodies (from mouse) conjugated with gold nanoparticles as the marker by passive absorption and covalent coupling, deposited in an elaborate pad. To form control and test zones, anti-mouse antibody and a BVA-BSA conjugate were spotted on the nitrocellulose membrane, respectively.
Negative samples are revealed by red lines both in the test and control zones, respectively, whereas positive samples produce a single red line only in the control zone. The measurement range is 0.05 – 23 μg/L, visually detected by the naked eye within 5 minutes. In addition, the intensities at the test line can be read by dedicated lateral flow readers (opTrilyzer® and Cube by opTricon, Berlin) for a more precise and documented determination.
An immunochromatographic assay for the determination of bisphenol a releases from plastic materials
(2018)
Background. The worldwide increase in the use of bisphenol A (BPA), a monomer commonly used to manufacture polycarbonate plastic products and the epoxy resins that line metal cans, has resulted in an increased human exposure because both products come in contact with food and beverages. Since BPA is an endocrine disruptor excessive exposure could affect human reproductive function. In response, various countries have adopted a range of measures, from voluntary reductions to outright bans of BPA in some products, mostly in baby bottles and containers for canned foods. Nonetheless, consumers would certainly appreciate a quick test for their own assessment of contaminations by bisphenol A.
Methods. An immunochromatographic test strip was developed. This lateral-flow immunoassay (LFIA) is based on anti-BPA antibodies (from mouse) conjugated with gold nanoparticles as the marker, deposited in an elaborate pad. To form control and test zones, anti-mouse antibody and a BPA-BSA conjugate were spotted on the nitrocellulose membrane, respectively.
Results. Negative samples are revealed by red lines both in the test and control zones, respectively, whereas positive samples produce a single red line only in the control zone. The limit of detection (LOD) was found to be 0.05 µg/l, visually detected by the naked eye within 5 minutes. In addition, the intensities at the test line can be read by dedicated lateral flow readers (opTrilyzer® and Cube by opTricon, Berlin) for a more precise and documented determination.
Conclusion. Pregnancy-test like strips in combination with hand-held readers provide a simple and versatile tool to determine the presence of bisphenol A quantitatively, making it a very attractive analytical approach especially for on-site applications at critical points, such as environmental analysis, consumer protection, and materials testing.
Bisphenol A (BPA), a monomer commonly used to manufacture polycarbonate plastic products and the epoxy resins that line metal cans, has resulted in an increased human exposure because both products come in contact with food and beverages. Since BPA is an endocrine disruptor excessive exposure could affect human reproductive function. In response, various countries have adopted a range of measures, from voluntary reductions to outright bans of BPA in some products, mostly in baby bottles and containers for canned foods. Pregnancy-test like strips in combination with hand-held readers provide a simple and versatile tool to determine the presence of bisphenol A quantitatively, making it a very attractive analytical approach especially for on-site applications at critical points, such as environmental analysis, consumer protection, and materials testing.
Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umwelt-beständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden.
Monitoring programs should generate high-quality data on the concentrations of substances and other pollutants in the aquatic environment to enable reliable risk assessment. Furthermore, the need for comparability over space and time is critical for analysis of trends and evaluation of restoration of natural environment. Additionally, research work and exercises at the European level have highlighted that reliable measurements of estrogenic substances at the PNEC level are still challenging to achieve.
The project EDC-WFD Metrology for monitoring endocrine disrupting compounds under the EU Water Framework Directive aims to develop traceable analytical methods for determining endocrine disrupting compounds and their effects, with a specific focus on three estrogens of the first watch list (17-beta-estradiol (17βE2), 17-alpha-ethinylestradiol (EE2), and estrone (E1)). Estrogens 17-alpha-estradiol (17E2) and estriol (E3) will be included to demonstrate the reliability of the developed methods and to support the requirements of Directive 2013/39/EC, Directive 2009/90/EC and Commission Implementation Decision (EU) 2018/840, hence improving the comparability and compatibility of measurement results within Europe. During the EDC-WFD project four selected effect-based methods (EBM) will be deeply investigated in order to improve their rationale use and their support in water quality assessment. In particular, the EBM sensitivity, specificity and accuracy on reference materials with single or mixture solutions of the five substances at a concentration of EQS values will be explored.
This contribution will present the objectives and methods applied within the EDC-WFD project.
Natural and synthetic estrogens are key endocrine-disrupting chemicals. Despite occurring at ultra-trace levels (below ng L-1), it is believed that they are contributing to an increase in feminized fish and other endocrine disruptive effects, and hence, their inclusion in the Watch list was not unexpected. One of the main sources ofestrogens to surface waters is wastewater effluent. Once in surface waters, they can partition into different compartments, i.e., water and suspended particulate matter. For this reason, there is an urgent need for a methodology to monitor estrogen levels below the environmental quality standards (EQS) set by the Water Framework Directive requirements.
In this study, a precise and accurate gas chromatography-mass spectrometry method (GC-MS/MS) for the analysis of estrone (E1), 17β-estradiol (17β-E2), 17α-estradiol (17α- E2), 17-alpha-ethinylestradiol (EE2), and estriol (E3) in whole water samples with ng L-1 limit of quantification (LOQ) was developed and validated in accordance with CEN/TS 16800:2020 guidelines.
Warfarin als ein Vertreter der NSO-Hetereozyklen, ist seit den 1950er Jahren einer der bekanntesten Gerinnungshemmer. Beim Menschen wird es bis heute zur Vorbeugung von Thrombose und der Behandlung von Vorhofflimmern und Arrhythmie eingesetzt. Doch schon einige Jahre vor der FDA Zulassung als Medikament wurde es zur Bekämpfung von Nagetieren eingesetzt. Bis heute wurde es nur teilweise durch weitaus wirksamere antikoagulante Rodentizide (ARs) der zweiten Generation, sogenannte Superwarfarine, ersetzt. In der Fachliteratur finden sich zahlreiche Beispiele für sekundäre und tertiäre Vergiftung mit ARs bei Wildtieren und anderen Nichtzieltieren. Bisher ist relativ wenig über die Bioakkumulation, Persistenz und Toxizität von ARs und deren Transformationsprodukten (TPs) in der terrestrischen und aquatischen Umwelt, sowie der Nahrungskette bekannt.
Um Einblicke in mögliche Transformations- und Abbauprozesse von Warfarin zu erhalten und um Umwelteinflüsse zu simulieren, wurde es in einer elektrochemischen Reaktorzelle oxidativ umgesetzt und mittels Massenspektrometrie analysiert. Hinsichtlich der Wasseraufbereitung in Kläranlagen wurden technisch relevante Simulationsverfahren wie Chlorung, UV-Bestrahlung und Ozonung angewendet um potentielle Eliminierungswege aufzuklären. Gebildete Transformationsprodukte wurden daher mittels unterschiedlicher chromatografischer Verfahren getrennt, massenspektrometrisch analysiert und verglichen.
Warfarin, also known as Coumadin is one of the most popular anticoagulant drugs used as a therapeutic in humans to prevent thrombosis, atrial fibrosis, and fibrillation since the 1950s. Because of its ability to hinder blood from clotting by blocking vitamin K-depending carboxylation of blood clotting precursors, it is also used as a rodenticide worldwide. Until today it has been partially substituted by far more potent anticoagulant rodenticides (ARs), so-called superwarfarins. There are numerous references confirming secondary and tertiary poisoning in non-target-animals and wildlife like mammals, birds, and fish associated with ARs. Up to now relatively little is known about persistence and toxicity of transformation products of those AR in the environment and food chain. Herein, warfarin was chosen as a model compound to determine andelucidate TPs which are generated technically and under environment-like conditions. Such as the simulation of the oxidative phase I metabolism by implementing electrochemical flow cells coupled to mass spectrometry (MS). Obtained results are being compared to TPs generated by UVB-irradiation and ozonation.
Analysis and separation of degradation products and TPs were achieved by a variety of gas- and liquid chromatographic techniques coupled to (high resolution) MS.
Monitoring programs should generate high-quality data on the concentrations of substances and other pollutants in the aquatic environment to enable reliable risk assessment. Furthermore, the need for comparability over space and time is critical for analysis of trends and evaluation of restoration of natural environment. Additionally, research work and exercises at the European level have highlighted that reliable measurements of estrogenic substances at the PNEC level are still challenging to achieve. The project EDC-WFD “Metrology for monitoring endocrine disrupting compounds under the EU Water Framework Directive” aims to develop traceable analytical methods for determining endocrine disrupting compounds and their effects, with a specific focus on three estrogens of the first watch list (17-beta-estradiol (17βE2), 17-alpha-ethinylestradiol (EE2), and estrone (E1)). Estrogens 17-alpha-estradiol (17aE2) and estriol (E3) will be included to demonstrate the reliability of the developed methods - Mass Spectrometry based method and effect-based methods (EBM) - and to support the requirements of Directive 2013/39/EC, Directive 2009/90/EC and Commission Implementation Decision (EU) 2018/840, hence improving the comparability and compatibility of measurement results within Europe. During the EDC-WFD project four EBM will be deeply investigated in order to improve their rationale use and their support in water quality assessment.
For years there have been more and more reports on the presence of drugs in the aquatic environment. Due to the demographic change, the consumption of pharmaceuticals has risen sharply. After taking the drugs, they are partly metabolized in the human body. However, the metabolism is not complete so that both the metabolites and non-metabolized amounts of the parent compounds are excreted. These compounds reach the waste water and afterwards the sewage treatment plants. In sewage treatment plants transformation products can be formed by the oxidative conditions during wastewater treatment processes. The transformation products may have a higher toxicity than the actual environmental pollutants and are often only partly removed during the waste water treatment. Since a lot of these compounds are still unknown, the transformation products are not detected by target analysis used in sewage treatment plants and are often released undetected in the aquatic ecosystems. The released substances may be subject to additional transformation processes in the environment. Pharmaceuticals produced in high amounts can be already detected in the μg/L range in water bodies worldwide.
Metformin and its major transformation product guanylurea are one of the main representatives. Metformin is the drug of choice for treating type 2 diabetes. The drug therapy for diabetes mellitus has increased significantly in recent years. In the year 2015 1500 tons of metformin were prescribed in Germany (for statutory insured persons). Metformin is not metabolized in the human body and is excreted unchanged therefore concentrations between 57 μg/L and 129 μg/L are found in German waste water treatment plants influents.
In this work the transformation of the antidiabetic drug metformin is investigated. The degradation of metformin is initialize by commercial water treatment techniques like UV-radiation or noncommercial techniques like heterogenous photocatalysis based on titanium dioxide. The degradation of metformin and resulting transformation products are analyzed by LC-MS/MS and LC-HRMS.
Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umweltbeständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz, die jeweils mit polybromierten Flammschutzmitteln (PBFSM) versehen sind. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Auch soll mit Hilfe der RFA und der LA-ICP-MS die Abreicherung der PBFSM in den Modellmaterialien beschrieben werden. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden.
Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umweltbeständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz, die jeweils mit polybromierten Flammschutzmitteln (PBFSM) versehen sind. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Auch soll mit Hilfe der RFA und der LA-ICP-MS die Abreicherung der PBFSM in den Modellmaterialien beschrieben werden. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden.
Zu den letzten beiden Jahrestagungen der GUS wurden Verfahren und Methoden vorgestellt, die es gestatten, den Transfer von Schadstoffen aus Materialien und Produkten in die Umwelt unter umweltrelevanten Bedingungen beschreiben zu können. Dabei lag der Fokus auf den Materialien und der eingesetzten Umweltsimulationen. In einem sich anschließenden Schritt soll nun das Verhalten der freigesetzten organischen Schadstoffe unter den Bedingungen von realen und simulierten Umwelteinflüssen charakterisiert und beschrieben werden. Hier werden im Detail drei potentielle Schadstoffe betrachtet, die Inhaltsstoffe bzw. Additive in den jeweils eingesetzten Materialien sind. Im Falle von Polypropylen (PP) und Polystyrol (PS) handelt es sich um polybromierte Flammschutzmittel BDE 209 (Decabrom-diphenylether, als Einzelsubstanz) und HBCD (Hexabromcyclododecan, als technische Formulierung). Für das eingesetzte Polycarbonat ist BPA (Bisphenol A) als Schadstoff zu definieren, welcher unter umweltrelevanten Bedingungen freigesetzt wird. Im Rahmen der durchzuführenden Arbeiten sollen die aufgeführten prioritären Schadstoffe hinsichtlich möglicher Transformationsprozesse in Umwelt und Klärwerk charakterisiert werden. Die unter den Bedingungen der Ozonung, Chlorierung und UV-Bestrahlung erhaltenen Transformationsprodukte (TPs) sollen im Sinne einer Non-Target-Analytik identifiziert und eindeutig charakterisiert werden. Die Ergebnisse sollen mittels vorhandener Analysenverfahren, wie GC-EI-MS, HPLC-ESI-IT-MSn bzw. LC-MS/MS erzeugt bzw. abgesichert werden. Anhand der in der Struktur eindeutig zu beschreibenden Transformationsprodukte und der Charakterisierung von potentiellen Intermediaten sollen belastbare Reaktionswege und –mechanismen abgeleitet werden.
Environmental sustainability and –stability of Materials concerning the Migration of pollutants
(2018)
MaUS is an acronym for ”Material und Umweltsimulationen“. Plastics are in the focus of environmental politics due to their long-term behaviour and therefore to their persistence. Not only that they appear as visible contaminants in the sea and on the beach, but their unknown behaviour concerning their additives as well as the related transformation products are anxious. Therefore, we wish to establish a certified reference method to provide a method for testing plastics.
Aim of this project is the development of fast motion standard reference methods for testing plastics regarding to their environmental compatibility. To establish these testing methods, we use polystyrene (PS) and polypropylene (PP) with environmental relevant brominated flame retardants, known for their persistent bioaccumulative and toxic (PBT) properties. In case of PS the material contains 1 wt% of 1,2,5,6,9,10-hexabromocyclododecan (HBCD) and in case of PP 0.1 wt% bromodiphenylether (BDE-209), which is known as a substance of very high concern (SVHC). Furthermore, we use polycarbonate (PC), which is still used as material in baby flasks and releases Bisphenol A (BPA), an estrogenic active substance.
As an additional material PTFE is used for its importance as a source for two ubiquitous environmental substances (PFOS and PFOA), whose toxicological effects are still incompletely known.
The focus in this current work is set on the transfer of potential pollutants out of applied materials mentioned above into environmental compartments like water or soil. Here an accelerated aging concept should be developed to shortened time consuming natural processes. For these resulting simulations we use a programmable weathering chamber with dry and wet periods and with high and low temperatures. These programmes run for several weeks and according to a defined sampling schedule we take water samples, run a clean-up procedure by SPE (Molecular imprinted polymers (MiPs) resp. polymer-based cartridges (Waters Oasis HLB)) and analyse them by HPLC-UV resp. LC-MS/MS. Of most interest in case of flame retardants are photocatalytic transformation products. Therefore, we conduct a non-target-screening resp. a suspected target-screening by LC-MS/MS and HRMS.
Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umwelt-beständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe (polybromierte Flammschutzmittel) in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden.
In addition to previously reported results on the accelerated weathering of polystyrene samples (PS) containing 1 wt.% hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene samples (PP) containing 0.1 wt.% BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006. For the determination of BDE-209 in the collected raining water the samples were prepared in accordance to a validated protocol. Before the analyses each sample was spiked with isotopically labeled BDE-209. Subsequently the samples were extracted with isooctane. The obtained extracts were concentrated, and the resulting solutions were analyzed by GC/MS. Additionally, the total bromine content was monitored for the weathered and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence analysis (XRF) as a non-destructive and rapid method. In general, the resulting data from the accelerated weathering will be compared to those from the natural weathering experiments. Here, the surfaces of the test pieces were analyzed by LA-ICP-MS and XRF as well. Moreover, soil bed tests were conducted in a well characterized model soil. This soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining basin inside of an air-conditioned cellar. In this manner, TOC, water capacity and humidity are recorded parameters. To induce a leaching process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. A defined humidity is a fundamental parameter for a biological activity in the soil. The test polymers were placed up to the half in the soil. Microbial activity of the soil is monitored by a reference polymer (polyurethane) and should induce the release of HBCD and BDE-209 out of the test materials. These released analytes will be captured by passive samplers (silicone tubes) placed in a distinct distance to the polymer samples in the soil. The soil bed experiments are complementary to the weathering experiments due to the biological activity in the soil.
Gegenstand des Projekts ist die Prüfung der Umweltbeständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polycarbonat, Polytetrafluorethylen, Polystyrol und Polypropylen zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden, die es gestatten, Schnellprüfverfahren zu etablieren, die die Simulation der realen Beanspruchungen im Zeitraffermodell anwendbar machen. Somit sollen standardisierbare Schnellbeanspruchungs-verfahren erarbeitet werden, die als Prüfeinrichtungen etabliert werden und von externen Auftraggebern zur Prüfung der Umweltbeständigkeit und -verträglichkeit von neuen Materialien genutzt werden können. Die Umweltwirkungen (chemisch-physikalisch und mikrobiologisch) sollen so definiert eingesetzt werden, dass eine reproduzierbare Prüfung möglich wird. Aus diesen Verfahren und Methoden sollen Normen abgeleitet werden, die eine standardisierte Materialprüfung ermöglichen.
Environmental sustainability and –stability of materials concerning the migration of pollutants
(2019)
In addition to previously reported results on the accelerated weathering of polystyrene samples (PS) containing 1 wt. % hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene samples (PP) containing 0.1 wt. % BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006. For the determination of BDE-209 in the collected raining water the samples were prepared in accordance to a validated protocol. Before the analyses each sample was spiked with isotopically labeled BDE-209. Subsequently the samples were extracted with isooctane. The obtained extracts were concentrated, and the resulting solutions were analyzed by GC/MS. Additionally, the total bromine content was monitored for the weathered and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence analysis (XRF) as a non-destructive and rapid method. In general, the resulting data from the accelerated weathering will be compared to those from the natural weathering experiments. Here, the surfaces of the test pieces were analyzed by LA-ICP-MS and XRF as well. Moreover, soil bed tests were conducted in a well characterized model soil. This soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining basin inside of an air-conditioned cellar. In this manner, TOC, water capacity and humidity are recorded parameters. To induce a leaching process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. A defined humidity is a fundamental parameter for a biological activity in the soil. The test polymers were placed up to the half in the soil. Microbial activity of the soil is monitored by a reference polymer (polyurethane) and should induce the release of HBCD and BDE-209 out of the test materials. These released analytes will be captured by passive samplers (silicone tubes) placed in a distinct distance to the polymer samples in the soil. The soil bed experiments are complementary to the weathering experiments due to the biological activity in the soil.
In addition to previously reported results on the simulated aging of polystyrene samples (PS) containing 1 wt. % hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene (PP)-samples containing 0.1 wt. % BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006.For the determination of BDE-209 in the collected rain water samples derived from the used climate chamber, the samples were prepared in accordance with a validated protocol. Before the analyses, each sample was spiked with 2 µL of isotopically labeled BDE-209 (13C10-BDE-209) to serve as internal standard (ISTD) in the performed stable isotope dilution analysis. Subsequently the samples were extracted with isooctane, the obtained aliquots of the extracts were concentrated to 200 µL and 2 µL of the resulting solution were injected to the GC/MS for quantification.
Additionally, the total bromine contents are monitored for the aged and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as well as X-ray fluorescence analysis (XRF) as non-destructive and rapid method. Furthermore, results from surface analysis using environmental scanning electron microscopy (ESEM) for morphological characterization of the aged and untreated samples were presented and discussed. In general, the resulting data from the accelerated aging will be compared to those from the natural weathering experiments (“atmospheric exposure”, in soil).
The atmospheric exposure was performed by placing the samples on a weathering rack, which is aligned in SW direction (in a 45° angle to the horizon). The weathering data were regularly recorded by Deutscher Wetterdienst at this site. The surfaces of the test specimens (aged and stored references) were analyzed by ESEM as well as by LA-ICP-MS and by XRF. The surface of PS and PP specimens aged outdoors present the aging under real conditions and allow the comparison to the accelerated aged specimens by means of the weathering chamber. This way, we explore the efficiency of the accelerated aging procedure, which provides the advantage of well-defined and reproducible conditions compared to natural weathering, as a tool for testing different plastic materials.
Additionally “in soil” experiments were conducted in-door in a well characterized testing soil. The soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining concrete basin inside of an air-conditioned room. In this manner, TOC, water capacity and humidity are recorded parameters. To assure a washing out process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. The water content is additionally monitored by weight of the basin, capturing water from raining periods. The correct humidity is a fundamental parameter for biological activity. Samples of PS resp. PP were of dimension 10x1cm and 5 specimens were placed up to the half in the soil per basin. Microbial activity of the soil, monitored by the reference polyurethane, sets HBCD resp. BDE-209 of the samples free and will be leached from the samples by raining water. Thereafter these will be captured by passive samplers placed in a distinct distance to the samples in the soil. The “in soil” experiments are complementary to the weathering experiments due to the biological activity in the soil. These experiments simulate the fate of the brominated flame retardants in the biosphere.
In addition to previously reported results on the accelerated weathering of polystyrene samples (PS) containing 1 wt.% hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene samples (PP) containing 0.1 wt.% BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006. For the determination of BDE-209 in the collected raining water the samples were prepared in accordance to a validated protocol. Before the analyses each sample was spiked with isotopically labeled BDE-209. Subsequently the samples were extracted with isooctane. The obtained extracts were concentrated, and the resulting solutions were analyzed by GC/MS. Additionally, the total bromine content was monitored for the weathered and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence analysis (XRF) as a non-destructive and rapid method. In general, the resulting data from the accelerated weathering will be compared to those from the natural weathering experiments. Here, the surfaces of the test pieces were analyzed by LA-ICP-MS and XRF as well. Moreover, soil bed tests were conducted in a well characterized model soil. This soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining basin inside of an air-conditioned cellar. In this manner, TOC, water capacity and humidity are recorded parameters. To induce a leaching process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. A defined humidity is a fundamental parameter for a biological activity in the soil. The test polymers were placed up to the half in the soil. Microbial activity of the soil is monitored by a reference polymer (polyurethane) and should induce the release of HBCD and BDE-209 out of the test materials. These released analytes will be captured by passive samplers (silicone tubes) placed in a distinct distance to the polymer samples in the soil. The soil bed experiments are complementary to the weathering experiments due to the biological activity in the soil.
A process spectroscopic approach for the monitoring of microplastics in environmental samples
(2018)
The potential of Raman and NIR process-spectroscopic as a rapid approach for the estimation of microplastics (MP) in soil matrix were tested. For this purpose, artificial MP/soil mixture samples consisting of standard soils or sand with defined ratios of MP (0,5 – 10 mass% polymer) from polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET) were prepared. MP particles with diameters < 2 mm and < 125 µm were obtained from industrial polymer pellets after cryo-milling. Spectra of these mixtures were collected by (i) a process FT-NIR spectrometer equipped with a reflection probe, (ii) by a cw-process Raman spectrometer and (iii) by a time-gated Raman spectrometer using fiber-optic probes. The evaluation of process-spectra was performed by chemometric methods. Whereas MP could be detected by Raman spectroscopy in coastal sand at 0.5 mass%, in standard soil detection of MP was limited to 10 – 5 mass% with the large fraction, but samples containing particles of the 125µm mass-fraction yielded no positive result at all. One reason for the lacking sensitivity could be fluorescence by soil organic matter and thus, in a next test time-gated Raman spectroscopy was applied. However, although being indeed more sensitive to the small particles this method failed at MP < 5 mass% indicating that fluorescence was not the major problem. Finally, FT-NIR was tested. Depending on the polymer, MP contents of 0,5 or 1 mass%, respectively, could be detected in standard soils and polymers identified. Furthermore, this approach could be used for the investigation of mixtures of up to four polymers and in real-world samples from bio-waste fermenter residues.
The interaction of microcroplastics (MP) with dissolved organic matter, especially humic substances, is of great importance in understanding the behavior of microplastics in aquatic ecosystems. Surface modification by humic substances plays an essential role in transport and interaction of MP with abiotic and biotic components. Previous studies on the interaction between MP and humic substances were largely based on a model compound, humic acid (Sigma-Aldrich). In our work, we therefore investigated the interaction of natural organic matter (NOM) sampled from a German surface water with low-density polyethylene particles (LDPE). Highpressure size exclusion chromatography (HPSEC) and UV/vis absorption and fluorescence spectroscopy were used to characterize the incubation solutions after modifications due to the presence of LDPE, and Raman spectroscopy was used to characterize the incubated microplastics. While the studies of the solutions generally showed only very small effects, Raman spectroscopic studies allowed clear evidence of the binding of humic fractions to MP. The comparison of the incubation of NOM and a lignite fulvic acid which also was tested further showed that specific signatures of the humic substances used could be detected by Raman spectroscopy. This provides an elegant opportunity to conduct broader studies on this issue in the future.
In Deutschland werden jährlich rund 20 Millionen Tonnen künstliche Mineralwolle für die Dämmung von Dächern und Fassaden sowie für Brandschutzprodukte verwendet. Um künstliche Mineralwolle aus Rückbaumaßnahmen in den Produktionsprozess zurückführen zu können, ist eine Trennung in Glas- und Steinwolle erforderlich, um eine Vermischung der beiden Produkte, die unterschiedliche Schmelztemperaturen aufweisen, zu vermeiden. Anstatt die Mineralwolle in spezielle Labors zu schicken, was zeitaufwendig und teuer ist, wurde das Potenzial eines tragbaren Nahinfrarot-Spektrometers (NIR) für den Einsatz vor Ort getestet. 140 verschiedene Mineralwolleproben wurden untersucht, um eine NIR-basierte Methode für die Vor-Ort-Unterscheidung zwischen Glas- und Steinwolle zu etablieren. Die Validierung der Methode mit Testproben und die Anwendung auf Materialien, die aus BigBags für Deponien entnommen wurden, haben gezeigt, dass die Methode präzise und robust ist. Als Referenzmethode wurde die Röntgenfluoreszenzspektroskopie (RFA) mit einer Kalibrierung auf der Grundlage der VDI 3492 verwendet.
Bei der vom Bundesministerium für Bildung und Forschung (BMBF) geförderten Förderinitiative „BonaRes“ steht die nachhaltige Nutzung der knappen Ressource Boden im Fokus. Das durch BonaRes geförderte Verbundprojekt „Intelligence for Soil“ (I4S) hat sich die Entwicklung eines integrierten Systems zur ortsspezifischen Steuerung der Bodenfruchtbarkeit zur Aufgabe gemacht, welches Empfehlungen zur Anpassung der Düngung und anderer Maßnahmen gibt, um die Bodenfunktionen zu verbessern und Umweltbelastungen zu vermindern. Das System soll aus drei Hauptkomponenten bestehen:
- Mobile Sensorplattform zur hochauflösenden Kartierung der Bodeneigenschaften (BonaRes Mapper). Die Sensorplattform enthält Bodensensoren zur komplexen Erfassung bewirtschaftungsrelevanter Bodeneigenschaften in situ.
- Dynamische Bodenmodelle (Nährstoff-, Wasser-, C-Haushalt) zur Verarbeitung der Sensordaten und Erzeugung entscheidungsrelevanter Informationen,
- Entscheidungsunterstützungssystem (EUS), welches in die Bodenmodelle agronomische und sozioökonomische Randbedingungen integriert, Düngungsempfehlungen ausspricht und Bodenfunktionen bewertet. Der Output des EUS sind insbesondere Düngungskarten für die ortsspezifische Düngung im Rahmen von Precision Agriculture.
Der Erhalt und die Verbesserung der Fruchtbarkeit von Böden durch landwirtschaftliche Bewirtschaftungsmaßnahmen erfordert sorgfältig geplante Entscheidungen, die auf einer detaillierten Erfassung der Bodeneigenschaften und einem vertieften Verständnis der Bodenprozesse beruhen. Durch konventionelle, flächeneinheitliche Bewirtschaftungen (z.B. Düngung) können zum einen Ertragsverluste durch zu geringe Bewirtschaftungsintensität auf dem einen Teil der Fläche verursacht werden, während andere Teile des Feldes zu hohe Dosen erhalten und es dadurch zu Umweltbelastungen oder zu Verschwendung von Ressourcen kommt. Trotz der Verfügbarkeit von Technologien für ortsspezifische Düngung ist die Akzeptanz ortsspezifischer Bewirtschaftung (Precision Agriculture) in der Praxis noch gering. Ein wesentlicher Grund dafür ist das Fehlen von kostengünstigen Methoden zur Erfassung der bewirtschaftungsrelevanten Bodenmerkmale. Für die elementanalytische Untersuchung von Böden vor-Ort ist eine zuverlässige Analytik und Prozessüberwachung wie z.B. durch RFA oder LIBS erforderlich.
Around 2.5 million tons of municipal sewage sludge (dry matter) are produced in Ger-many every year. The disposal or recycling of this mass often confronts plant operators with considerable problems. In addition to organic substances, sewage sludges also contain important inorganic nutrients that can be recycled. Due to the finite nature of phosphorus as a resource and in favor of natural material cycles, it makes sense to utilize the phosphorus bound in sewage sludge. Therefore, Phosphorus recycling from sewage sludge will be obligatory in Germany from 2029. However, the pollutants pre-sent in sewage sludge, such as heavy metals and organic trace pollutants, are prob-lematic. In many cases, the sewage sludge is incinerated, removing organic compo-nents, and leaving a mineral residue. Various processes exist for the reprocessing of sewage sludge ashes. Reliable analytics and process monitoring are required for all of them.
In this context, the first and most important task of BAM regarding new materials or processes is safety in technology and chemistry through validated and correct analyt-ics. Since there are no reference materials for sewage sludge ashes so far, it is not possible to make any statements about the extent to which the measured values of the comparative measuring methods are correct at all. Therefore, suitable, and representa-tive reference materials are indispensable for the validation of the measurement results and the quality assurance during the entire recycling process. Great care is required to select and prepare these reference materials. The reference materials must corre-spond in matrix to the samples that are to be investigated in the industrial process. An iron-rich and an aluminum-rich sewage sludge ash from mono-incineration plants were selected for this purpose. 10 kg of each sewage sludge ash were homogenized, char-acterized, and prepared. The main, minor and trace element compositions of the sew-age sludge ashes are determined by different measuring methods. The candidate ref-erence materials will be available as BAM-U200 und BAM-U201.
Deciphering microbiological influenced corrosion processes on steel with single cell-ICP-ToF-MS
(2022)
Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. The information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research.
Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. The information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research.
Deciphering microbiological influenced corrosion processes on steel with single cell-ICP-ToF-MS
(2022)
Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. The information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research.
References.
Problem: Lack of knowledge about TCE stocks and flows in urban mines. TCE analysis is hindered by extreme heterogeneity of the waste and a lack of suitable CRMs. Analytical procedures providing SI traceable results are not available.
Solution: To enable comparability of analytical results and thus finally allow the improved recycling procedures, sampling strategies, analytical procedures, enabling SI traceable values and CRMs for TCE to be developed.
Antifoulingmittel im Wasser
(2019)
Materials are key for our modern communities. In particular metals play important roles in all areas of our daily life - from building materials to high tech products.
Due to the increasing consumption of metals and corresponding waste production, an elevated release into the environment takes place. Furthermore, metals in direct contact with the environment undergo corrosion leading to a release into the (aquatic) environment. Thus, lifespan of products/buildings are substantially reduced – hence unnecessary economic costs arise. Thus, research in this regard is needed within the force field of metal/material - environment.
Evaluating the environmental impact of materials as well as developing “safe” materials, new analytical methods are highly needed. One promising powerful tool is single cell-ICP-ToF-MS for multi-elemental analysis on a single cell/organism level.
Within this presentation the concept, strength as well as challenge of single cell-ICP-MS are briefly introduced. Two application examples are presented: (i) assessing the environmental impact of metals and (ii) the impact of the environment on metal-based materials and the derivation of potential environmental-friendly material protection strategies. These applications highlight the strength of new analytical approaches to explore the durability and safety of newly developed materials. Thus, analytical chemistry is one corner stone to transformation of modern society into circular economy (CEco).
(i) Diatoms are located at the bottom of the food chain. Thus, toxicological relevant metals taken up by diatoms possibly accumulate within the food web causing harmful effects. Diatoms are common test system in ecotoxicology. To investigate potential metal uptake and effects, we developed an on-line single cell-ICP-ToF-MS approach for multi-elemental diatom analysis. Our approach is a new potential tool in ecotoxicological testing for metal-based materials.
(ii) Next to classical corrosion processes, microorganisms are responsible for so called microbially influenced corrosion (MIC). MIC is a highly unpredictable process relying on interaction pathways between cells and the metal surface. Sheding light on MIC processes and derivate potential protection strategies, we applied single cell-ICP-ToF-MS for MIC research on a single bacteria/archaea level. It turned out that microorganism are taking up particular metals from alloys - thus, single bacteria-ICP-ToF-MS will enable development of corrosion protection strategies.