Chemische Charakterisierung und Spurenanalytik
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Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (59)
- 1.1 Anorganische Spurenanalytik (25)
- 6 Materialchemie (20)
- 1.4 Prozessanalytik (18)
- 6.3 Strukturanalytik (12)
- 1.6 Anorganische Referenzmaterialien (9)
- 6.6 Physik und chemische Analytik der Polymere (7)
- 1.7 Organische Spuren- und Lebensmittelanalytik (6)
- 1.8 Umweltanalytik (6)
- 1.9 Chemische und optische Sensorik (6)
Eingeladener Vortrag
- nein (83)
The transition from X-ray film to digital detectors in radiography is accompanied by an increase of unsharpness due to the larger inherent digital detector unsharpness in comparison to film. The basic spatial resolution of digital detectors (see EN ISO 17636-2) is used today to describe this unsharpness. The geometrical unsharpness of the radiographic projection of object structures onto the detector plane is determined by the focal spot size of the X-ray tube and the magnification. The focal spot size is measured today (see ASTM E 1165) from pin hole camera exposures or edge unsharpness (see ASTM E 2903). The final image unsharpness is a result of a convolution of the geometrical and inherent detector unsharpness function, divided by the magnification factor of the object onto the detector plane. Different approximations of this convolution result in ASTM E 1000 and ISO 17636-2 in different optimum values for the magnification factor for a given focal spot size of a X—ray tube and the basic spatial resolution of the detector. The higher contrast sensitivity, an advantage of digital radiography, compared to film radiography is furthermore improved when using higher X-ray voltages as used with film and smaller focal spots of the X-ray tubes. This allows a higher distance between object and detector resulting in reduced object scatter in the image. The interactions between all these parameters will be discussed and simple rules for practitioners will be derived in this contribution.
What is the future of Analytical Sciences? The talk starts with a definition, comparing the current view with that from 1968. How do wie set trends? How do we get Analytics inside? Some examples of "Big Science" are given and discussed in relation to a definition of AS. How does AS face the current Grand Challenges?
As exaples for something significant, several exaples are presented, such as Climate Change of Hydrogen Storage. Another important trand are eScience and automation concepts for AS, which are highlighted.
But (Analytical) Science has to be politcal in our times to face Fake News and to breake barriers!
Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important1,2.
In this presentation, a two-dimensional separation approach based on AF4 and CE was showed and used to separate NPs with similar sizes but different coatings. Standard reference polystyrene NPs having comparable core sizes but different coatings were investigated. Different migration time and profiles were compared. Separation in either method resulted in non-baseline resolved or non-separated peaks. In contrast, two-dimensional coupling of AF4 and CE resulted in clearly separated regions in their 2 D plots in case of 20 and 50 nm particle mixtures, whereas the 100 nm NP mixture could not be separated. Various factors affecting the separation like hydrodynamic diameter or SDS concentration were discussed.
Future investigations will be focussed on inorganic NPs with differently charged coatings. There, AF4-CE coupling can be coupled with inductively coupled plasma mass spectrometry (ICP-MS) to enhance the sensitivity of this method.
Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important.
A common method for nanoparticle separation, which was introduced in 1976 by Giddings, represents asymmetrical field-flow fractionation (AF4). It is a flow based separation method, which can be theoretically used to separate particles range from 1 nm to 50 µm. However, when the particles are smaller than 10 nm, separation with AF4 will become difficult to perform. Because in this case strong separation force, which induces aggregation of particles, should be applied. This will decrease recoveries of analytes and limit its application in accurate quantitative analysis. Capillary electrophoresis (CE) is another well-developed separation technique, in which samples will be separated in relation to their electrophoretic mobility. In recent years, CE has been used to separate different kinds of nanoparticles like, gold colloids or CdSe Quantum dots. However, till now only separation of particles smaller than 50 nm was reported. Because large size distribution of bigger particles will result in strong peak broadening and long separation time.
A two-dimensional coupling of AF4 and CE might provide us a new separation method, which can extend the separation ranges of both methods and be a way to characterise particles with large size distributions.
Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important.
A common method for nanoparticle separation, which was introduced in 1976 by Giddings, represents asymmetrical field-flow fractionation (AF4). It is a flow based separation method, which can be theoretically used to separate particles range from 1 nm to 50 µm. However, when the particles are smaller than 10 nm, separation with AF4 will become difficult to perform. Because in this case strong separation force, which induces aggregation of particles, should be applied. This will decrease recoveries of analytes and limit its application in accurate quantitative analysis. Capillary electrophoresis (CE) is another well-developed separation technique, in which samples will be separated in relation to their electrophoretic mobility. In recent years, CE has been used to separate different kinds of nanoparticles like, gold colloids or CdSe Quantum dots. However, till now only separation of particles smaller than 50 nm was reported. Because large size distribution of bigger particles will result in strong peak broadening and long separation time.
A two-dimensional coupling of AF4 and CE might provide us a new separation method, which can extend the separation ranges of both methods and be a way to characterise particles with large size distributions.
The accumulation of plastics leaked into the environment achieve a high perception in the last years. It is uncontroversial that often an uncontrolled, high consumption of plastic products and a poor waste management resulted in plastic findings all over in the environment. However, less is known about the relevant pathways and fate of plastic in the environment. Especially plastic fragments smaller 5 mmm, so called microplastics, achieve a high attention, because their amount and risks arising from these fragments are still unknown. The basic mechanisms of plastic or more precise, of different polymer degradation processes are often not considered, resulting in unrealistic statements.
For generation of fundamental understanding of this problem we developed in the last years a fast thermoanalytical method for identification and mass quantification of microplastics in complex samples. The presentation will also give a short introduction about polymer degradation.
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.
This presentation gives a short overview of isotope ratio measurements being carried out in the past few years at BAM in different fields such as plant metabolism, food web structures and archaeology. The corresponding isotope reference materials which have been certified at BAM in parallel are presented as well. Additionally an outlook is being provided on future iRM projects.
Der Vortrag gibt eine Übersicht über aktuelle qNMR-Aktivitäten im Fachbereich 1.4. Dies umfasst beispielsweise die Online-Anwendung zur Prozessüberwachung, aber auch die Reinheitsuntersuchung von Reinstoffkomponenten für die Herstellung von Referenzgasgemischen. Zusätzlich wird ein Ausblick in die aktuelle Strategie hinsichtlich der Rückführung von qNMR-Ergebnissen mittels primärer Referenzmaterialien gegeben.
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 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.
The analysis of non-metals normally is carried out using elemental analysers which require reference material for calibration. In the lecture the CRM-program of BAM suitable for non-metal-analysis is presented. There are CRMs available with non-metal contents in the low ppm up to the high percent region.
Surface functionalization of nanomaterials is nowadays at the core of many applications of functional materials in the life and material sciences. Examples range from membranes and microarrays over bead-based assays, and next generation sequencing to nanometer-sized optical reporters, nanosensors, and magnetic and optical contrast agents. Typical function-nalization steps include silanization and grafting reactions with reactive monomers to introduce functional groups like amino or carboxylic acid groups or the attachment of ligands like polyethylene glycol (PEG) molecules and biomolecules. [1-3] This enables to tune e.g., dis-persibility, hydrophilicity and biocompatibility, minimize unspecific interactions, improve biofunctionalization efficiencies, and enhance blood circulation times and allows for the use of nanomaterials as reporters in assays or the design of targeted probes for bioimaging.
At the core of all functionalization strategies are reliable and validated methods for surface group and ligand quantification that can be preferably performed with routine laboratory instrumentation, require only small amounts of substances, and are suitable for many different types of nanomaterials. [3] There is meanwhile a considerable need to make these methods traceable. We present here versatile and simple concepts for the quantification of common functional groups, ligands, and biomolecules on different types of organic and inorganic nanomaterials, using conventional and newly developed cleavable and multimodal reporters, that can be detected with optical spectroscopy. [4-7] These reporters are chosen to enable method validation with the aid of method comparisons and mass balances. Also, strategies how to make these simple assays traceable to SI units using quantitative nuclear resonance spectroscopy (qNMR) and X-ray photoelectron spectroscopy (XPS) are derived.
Analytical Sciences has developed from Ostwald’s “unentbehrlichen Dienstmagd” to a chemical discipline at the core of many of today’s fundamental and applied scientific problems and innovations. An atomic or molecular understanding of basic processes in chemistry, soft matter physics, materials and life science is enabled only through new analytical methods and instrumentation. Similar observations can be found for pressing sociopolitical conflicts of the future: A rational discussion of global climate change or new energy sources is only possible with reliable analytical results. Progress in Analytical Sciences is only possible if the underlying interdisciplinary character is acknowledged and valued. The talk will illustrate the scope of modern Analytical Science through examples from process analysis relevant to modern process intensification and industry 4.0 to bioanalysis and the use of synchrotron radiation to elucidate fundamental reactions materials.
An improved algorithm for calibration-free laser induced breakdown spectroscopy (CF LIBS) will be presented which includes several novel features in comparison with previously proposed similar algorithms. In particular, it allows using spectral lines with arbitrary optical thickness for the construction of Saha-Boltzmann plots, retrieves the absorption path length (plasma diameter) directly from a spectrum, replaces the Lorentzian line profile function by the Voigt function, and allows for self-absorption correction using pre-calculated and tabulated data rather than approximating functions. The tabulated data embody the solutions of the radiative transfer equation for numerous combinations of optical thicknesses and line widths. The algorithm is thoroughly verified using synthetic spectra.
Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic, metal-organic, and inorganic compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms often remain unclear. In the last years, we have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy. A further development is the in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time. [5] Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. Based on these data, metastable polymorphs of cocrystals and coordination polymorphs could be isolated and struc-turally characterized. A multi-step diffusion mechanism was identified for most systems. Crystalline phases were obtained intermediately, suggesting that the synthesis is following Ostwald’s rules of stages. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses.
Neurodegenerative diseases are one of the major problems for our ageing society. Alzheimer’s disease (AD) as the most common neurodegenerative disorder affects over 46.8 million people worldwide and the number will increase as the population ages. The diagnosis of AD is challenging and only half of the patients are identified yet and often only in late stages. One reason is that existing assays for identification and quantification of AD biomarkers lack accuracy and are poorly comparable.
This study is part of the EU project “ReMiND” aiming to develop accurate, reliable and traceable methods for the detection and quantification of known and suspected AD biomarkers. Our target is the tau protein, as brain load and distribution of tau is highly correlated with the clinical progression of AD. We intend to develop a measurement method for the accurate quantification of tau by means of inductively coupled plasma mass spectrometry (ICP-MS).
ICP-MS is a powerful method for the matrix independent quantitative analysis of target elements. Developed for the use in inorganic trace analysis, ICP-MS is nowadays emerging as a valuable tool for bioanalytical questions. Especially the use of ICP-MS for quantitative proteomics by measuring heteroatoms is highly promising, considering that established quantification methods like organic mass spectrometry depend on the existence of matched protein and peptide standards or labelling of the target protein. In this work, we applied isotope dilution analysis (IDA) using ICP-MS to quantify proteins of known stoichiometry via their sulphur content. Sulphur is present in two amino acids, cysteine and methionine, and hence is omnipresent in nearly all proteins. A NIST standard bovine serum albumin (BSA) was quantified using sulfur IDA to optimize sample preparation and method parameters. Our goal is to employ the developed method in a proof of concept study for the quantification of the AD biomarker tau extracted from brains of a mouse model for AD.
Gold ist eines der sieben schon im Altertum bekannten Metalle und wurde wg. seines Glanzes und seiner Seltenheit von alters her als Tauschmittel und zur Herstellung von Schmuck benutzt. Außerdem ist es einfach bearbeitbar und weitestgehend gegen chemische Einflüsse resistent. Die Untersuchungen von Gold mit synchrotronstrahlungsangeregter Röntgenfluoreszenzanalyse sind zerstörungsfrei und geben Auskunft über die in der untersuchten Probe vorhandenen chemischen Elemente. Bei den hier vorgestellten Untersuchungen an der BAMline stehen Fragestellungen wie Herkunft, Herstellungsverfahren und Zusammengehörigkeit von Goldfunden im Vordergrund. Die verschiedenen Fragestellungen werden an einer Reihe von Beispielen erläutert die vom Wikingerschatz aus Hiddensee über die Himmelsscheibe von Nebra bis hin zu Funden aus Ägypten langen. Zusätzlich werden die modernen Messmethoden vorgestellt, die am Synchrotron heutzutage zur Verfügung stehen.
Many current nanomaterials can serve as contrast agents in cellular or tissue imaging, drug delivery vehicles or therapeutics, whereas others can cause toxic effects. In order to evaluate nano-bio interactions, the number of nanoparticles (NPs) inside cells as well as their localisation within cellular substructures is of particular interest. The cellular uptake depends on the primary characteristics of the NPs (e.g. size, shape, surface coating) and on the cell type.
Laser ablation inductively coupled plasma mass spectrometry (LA‑ICP‑MS) is more and more used to study the NP pathway from uptake, via intracellular processing up to cell division. High-spatial resolution laser ablation at single cell level is achieved using novel low-dispersion LA chambers and by careful optimisation of laser energy, ablation frequency and scan speed at small laser spot sizes down to 1 µm. Different examples from BAM, Division 1.1 and cooperation partners using LA-ICP-MS to localize and quantify metal-containing nanoparticles are shown. The results demonstrate the potential of LA-ICP-MS providing insight into NP uptake, intracellular distribution and cell-to-cell variation.
qNMR provides the most universally applicable form of direct concentration or purity determination without need for reference materials of impurities or the calculation of response factors but only exhibiting suitable NMR properties. The workshop presents basic terms of statistics and uncertainty analysis, which are the basis for qNMR spectroscopy and data analysis such as, e.g., standard deviations, linear regression, significance tests, etc. and gives typical examples of applications in qNMR spectroscopy.
The Color X-ray Camera CXC or SLcam® is an energy-resolving X-ray camera capable of energy- and space-resolved measurements. It consists of a high-speed CCD detector coupled to a polycapil-lary optic that conducts the X-ray photons from the probe to distinct pixels onto the detector. The camera is capable of fast acquisition of spatially and energy resolved fluorescence images. A dedicated software enables the acquisition and the online processing of the spectral data for all 69696 pixels, leading to a real-time visualization of the elements distribution in a sample. It was developed in a joint project with BAM, IFG Berlin and PN Sensors. In this contribution we will mainly discuss the use of the CXC at our beamline, the BAMline at BESSY II and imaging applications of the CXC from different areas, like biology and archaeometry. Additionally new developments for the use of the detector without optics, like wavelength dispersive detection or 1shot-XANES, will be presented.
X-ray absorption fine structure spectroscopy (XAFS) is a frequently employed technique in order to investigate structural composition and change of chemical compounds such as catalytic species. These structural properties are essential (i) to understand underlying reaction mechanism and (ii) to further improve the design of efficient catalysts.
This investigation is based on a newly developed XAFS setup comprising both time- and lateral-resolved XAFS information simultaneously in a single-shot (S2XAFS). The primary broadband beam is generated by a filter/X-ray-mirror combination (bandpass). The transmitted beam through the sample is diffracted by a convexly bent Si (111) crystal, producing a divergent beam. This, in turn, is collected by an area sensitive detector with a theta to 2 theta geometry. This facile, stable and scanningless setup was tested at the BAMline @ BESSY-II (Berlin, Germany).
This contribution focuses on further experimental optimizations allowing the characterization of supported vanadium oxide (VOx) based catalysts at the lower hard X-ray regime (5 to 6 keV). First S2XAFS measurements of these catalysts are presented herein. Supported VOx catalysts show promising results in the oxidation of methane to formaldehyde.
S2XAFS allows determining the structural composition of the metal (i.e. vanadium) based on a fast and smart setup. It is therefore an ideal tool to identify crucial roles of chemical compounds in catalytic reactions.
XAFS@BAMline
(2018)
X-ray Absorption fine structure spectroscopy (XAFS) is a frequently employed technique in order to investigate structural composition and Change of chemical compounds such as catalytic species or corrosion processes. These structural properties are essential (i) to understand underlying reaction mechanism and (ii) to further improve the design of materials.
While XAFS measurements are usually performed with ionization Chambers or simple fluorescence detectors, we at BAMline specialize in measurements with innovative set-ups that meet Specialrequirements such as time resolution, (3D-) spatial Resolution or demanding sample environments.
This contribution presents various available XAFS configurations with their corresponding applications. In particular, these comprise single -shot XAFS for time- resolved measurements, grazing-exit XAFS with energy and a spatially resolved detector for the characterization of thin films and an in situ grazing incidence Setup for the characterization of corrosion layers.
Additionally,the possibility of analyzing Minute samples in total-reflection geometry is demonstrated.
To establish the SI traceability of the element content w(Hg) of a gravimetrically prepared 1 g/kg mercury solution, the latter was compared to a primary reference solution by means of high accuracy inductively coupled plasma optical emission spectrometry (ICP OES) measurements. For this purpose, the ICP OES bracketing method previously described [1] was improved to yield a relative expanded uncertainty of the mercury element content of Urel(w(Hg)) = 0.5 % (with k = 2) associated with the comparison of two monoelemental solutions. In case of mercury, such a small uncertainty was achieved for the first time. Before, in general, such small uncertainties were only reported applying isotope dilution methods performed with MC-ICP-MS. However, for mercury solutions at this concentration range, several dilution steps are necessary to prepare the samples for ID-MC-ICP-MS. The sum of the uncertainty contributions stemming from the dilution steps, as well as the intrinsic difficulties of measuring mercury at low concentrations, result in an overall uncertainty of the ICP-MS measurements, which is comparable to or even larger than those, achieved with the ICP OES method applied. We will present details of the sample preparation as well as of the dedicated ICP OES measurement approach, which were crucial to achieve such a small measurement uncertainty.
The newly developed method was successfully applied in the context of the development and production of elemental solution chemical reference standards (CRS), which are distributed by the EDQM. The CRS are intended to support measurements required by the European Pharmacopoeia, which has recently incorporated a new international guideline for the control of elemental impurities in medicinal products.
Analytical glow discharges with optical (GD-OES) and mass spectrometric (GD-MS) detection are able to obtain depth resolved information about the light elements hydrogen, carbon, nitrogen and oxygen in solid samples, where most of the other analytical techniques fail. However, the interpretation or even quantification of the measured signals is still very challenging. Problems arise due to physical effects (plasma processes such as the ‘Hydrogen effect’, the Doppler effect, self absorption or diffusion of hydrogen in the sample during sputtering) chemical effects(e.g. formation of compounds with argon or the matrix, poisoning of the sample or gettering) as well as instrumental difficulties (e.g. of the sensitivity, calibration and vacuum quality)..
The GD techniques are direct solid sampling methods and require reference materials for calibration. Unfortunately the list of available certified reference materials (CRM) suited for calibration of light elements in different matrix is relatively short Therefore, sintered materials doped with the analytes H2, O2 and N2 were produced at IFW Dresden and applied as calibration standards for hydrogen, oxygen and nitrogen. Due to the high analyte concentration added, it is very likely that the real concentration agree well with the added amount of light elements in the corresponding phases. The validation of the determination of the light element concentration in the sintered samples was possible in some cases only due to the lack of suitable techniques. This fact proves the need for the development of a reliable quantification of light elements by GDS.
A systematic dependence of the sputtering rate on the composition was found and can be explained by basic principles.
Using mixtures of TiH2 and ZrH2 with Cu the ratio of hydrogen and Cu lines has a good correlation with the corresponding concentration ratio. The hydrogen emission yield however decreases over 0.3 m% hydrogen and finally the hydrogen intensity may even decrease. This behaviour can be explained by a very similar quenching of the hydrogen and copper intensity caused by the hydrogen effect. First experiments with GD-MS show no saturation of the hydrogen ion current and thus confirm the quenching of the emission yield in GD-OES.
Sintered material for the oxygen calibration (Al2O3, CuO, Cu2O and MgO mixed with Cu, Al and Mg) confirmed the blue line shift effect at O I 130.22 nm, first time reported by Köster 2009 [1]. The effect is more pronounced at Mg than in Al and Cu, which due to line interference leads to a matrix dependent EY. This effect is negligible at O I 777.19 nm and the EY is matrix independent. Using GD-MS first promising results for the calibration of oxygen with these sintered samples could be obtained, when the sputtering rate was included in the evaluation.
More recently also sintered material for nitrogen calibration (AlN mixed with Al and Si3N4 mixed with Cu) was produced and points to a matrix independent emission yield of nitrogen
Reference materials are essential, when the accuracy and reliability of measurement results need to be guaranteed in order to generate confidence in the analysis.
These materials are frequently used for determining measurement uncertainty, for validation of methods, suitability testing and quality assurance. Especially direct solid sampling methods require reference materials for calibration.
They guarantee that measurement results can be compared to recognized reference values.
This presentation gives an overview about the use of GDMS in various certification procedures. Because it represents a fast, sensitive, multielement analyses technique without extensive sample preparation it plays a special role for the purity determination of high purity standards. Various calibration strategies and the preparation of traceable matrix matched calibration standards will be discussed.
For the certification of analyte content in matrix materials mainly techniques with solvent sample preparation are used. Here GD-MS is used to identify possible loss or contamination with analytes during the sample preparation step. Typically used acids to dissolve matrices lead to interferences in the ICP- mass spectrometric detection of various analytes and their quantification. Here GD-MS as direct method can also add an important contribution in the certification process.
Laser induced plasma (LIP) is a highly dynamic, short living event which presents significant difficulty for both diagnostics and modeling. The former requires precise spatially- and time-resolved measurements on a micron-nanosecond scale while the latter needs numerous descriptive parameters; many of them can only be obtained from experiment. Diagnostics and modeling should always complement each other for obtaining a truthful picture of LIP.
In this presentation, a newly developed collisional-dominated model will be presented. The model is based on the coupled Navier-Stokes, state, radiative transfer, material transport, and chemical equations. The model incorporates plasma chemistry through the equilibrium approach that relies on atomic and molecular partition functions. Several chemical systems are modeled including Si-C-Cl-N and B-H-Cl systems.
The model is used to study the equilibrium states of the systems as functions of the concentrations of plasma species and plasma temperature. The model also predicts the evolution of number densities of atomic and molecular species in the expanding plasma plume.
This course will provide an introduction to plasma diagnostic techniques. The major focus of the course will be on the discussions of the practical procedures as well as the underlying physical principles for the measurements of plasma fundamental characteristics (e.g., temperatures, thermodynamic properties, and electron number density). Particular emphasis will be placed on inductively coupled plasma–atomic emission spectrometry, but other analytical plasmas will also be used as examples when appropriate. Selected examples on how one can manipulate the operating conditions of the plasma source, based on the results of plasma diagnostic measurements, to improve its performance used for spectrochemical analysis will also be covered. Topics to be covered include thermal equilibrium, line profiles, temperatures, electron densities, excitation processes, microreactions, pump and probe diagnostics, tomography, temporal and spatial resolution. Basics of plasma computer modeling will be presented.
Generell ist es Ziel der Prozessführung, Reaktions- und Trennprozesse wirtschaftlich optimal zu betreiben. Hierzu werden in großen Anlagen modellbasiere Echtzeitoptimierungsverfahren (Real-time Optimization, RTO) eingesetzt. Die Qualität der Ergebnisse der Optimierung hängt dabei entscheidend von der Güte des verwendeten Modells ab. Die Entwicklung hochgenauer Modelle ist allerdings aufwändig, was für kleine Produktionsvolumina ein wesentliches Hindernis zur Nutzung solcher Methoden darstellt. Mit Hilfe der sogenannten Modifier-Adaptation ist eine iterative Betriebspunktoptimierung auch mit ungenauen Modellen möglich, wenn Messungen der für die Bewertung relevanten Größen (beispielsweise Produktkonzentrationen im Ausgangsstrom) verfügbar sein. Für eine Lithiierungsreaktion in einem bei INVITE kontinuierlich betriebenen Reaktor wurde im Rahmen des EU-Projekts CONSENS eine solche iterative Optimierung auf der Grundlage einer Messung der Zusammensetzung des Ausgangsstroms des Reaktors mit einem Online-NMR-Spektrometer realisiert. Das Spektrometer wurde an den Betrieb in einer explosionsgefährdeten Umgebung angepasst. Es konnte gezeigt werden, dass die Messdaten genau genug sind, um darauf eine Optimierung der Produktausbeute aufzubauen. Die iterative Optimierung führt den Prozess ausgehend vom mit dem Modell berechneten Betriebspunkt schrittweise zum wirtschaftlichen Optimum für die reale Anlage. Dabei reagiert die Optimierung auch auf unbekannte Abweichungen im Prozess (wie die Zusammensetzung des Feeds) und fährt iterativ den jeweils optimalen Betriebspunkt an.
Die Arbeiten wurden im Rahmen des EU-SPIRE-Projekts CONSENS, Förderkennzeichen 636942, durchgeführt.
Produzieren Sie schon oder kalibrieren Sie noch? – Online-NMR-Spektrometer als Smarte Feldgeräte
(2018)
Der Übergang von der aktuellen Automatisierungslandschaft zur nächsten Generation von Automatisierungskonzepten für die Prozessindustrie hat bereits begonnen. Intelligente Funktionen der Sensoren vereinfachen ihre Anwendung und ermöglichen eine Plug-and-Play-Integration, auch wenn sie auf den ersten Blick komplexer erscheinen mögen. Dies ist die Basis für die Digitalisierung der Prozessindustrie und hilft uns, komplexere Prozesse schneller umzusetzen.
Der Vortrag fasst die derzeit diskutierten allgemeinen Anforderungen an „Smarte Feldgeräte“ zusammen und diskutiert dieses am Beispiel eines smarten Online-NMR-Sensors. NMR-Spektroskopie bietet sich durch den Vorteil der direkten Vergleichsmethode (ohne Kalibrierung) für die Prozess-Steuerung an und verringert somit die Rüstzeiten. Zudem basiert der Sensor auf physikalisch motivierten Modellen (Indirect Hard Modeling, IHM), die sich modular kombinieren lassen. Die Methoden wurden anhand eines vorgegebenen pharmazeutischen Reaktionsschrittes im Rahmen des „Horizon 2020“-Projekts CONSENS der Europäischen Union demonstriert und validiert.
Zuletzt werden Anforderungen an die Weiterentwicklung der Datenauswertemethoden diskutiert, um letztlich die semantische Information aus den Messdaten herauszulesen oder das in der Industrie 4.0 geforderte „durchgehende Engineering“ für die Automatisierungskomponenten zu ermöglichen.
Atherosklerotische Läsionen können durch Magnetresonanztomographie (MRT) unter Verwendung von sehr kleinen Eisenoxidnanopartikeln (VSOP) sichtbar gemacht werden. VSOP akkumulieren in atherosklerotischen Plaques und dienen somit als Atherosklerosesonde.
Das Ziel dieses Projektes war die Abbildung der Verteilung von Europium-dotierten VSOP (Eu-VSOP) durch Laserablation ICP-MS in histologischen Dünnschnitten der Aortenwurzelregion des ApoE-Knockout-Mausmodells, das reich an atherosklerotischen Plaques ist. Darüber hinaus wurde untersucht, ob die VSOP-Akkumulation in den Plaques mit anderen Biomarkern der Entzündung wie Makrophagen und verändertem Endothel korreliert. Somit wäre eine Beurteilung, ob es sich hierbei um instabile bzw. vulnerable Plaque-Regionen handelt möglich. Zu diesem Zweck wurden Antikörper mit verschiedenen Lanthaniden markiert und mit der Eu-VSOP-Verteilung unter Verwendung von LA-ICP-MS in einem Multiplex-Messmodus korreliert.
Eine mögliche Korrelation von reaktiven Stickstoffspezies (RNS) mit endogenem Eisen oder Eu-VSOP kann ebenfalls durch LA-ICP-MS nachgewiesen werden. Zu diesem Zweck wurden RNS-spezifische Antikörper auch mit Lanthaniden markiert.
Analysis of single cells via LA-ICP-MS is a technique with great potential, however manual targeting of single cells is laborious and therefore microarraying of cells looks promising. In this work, we investigate the potential of a commercial non-contact piezo dispenser arraying system (S3, Scienion AG, Berlin), equipped with a novel technology for single-cell isolation called CellenONE™ (Cellenion, Lyon). Usually if one aims to create a microarray of single cells via spotting a suitably diluted cell suspension, one will observe a Poisson-distributed cell number per spot. CellenONE™ overcomes this problem by controlling the number of cells optically in the piezo dispense capillary (PDC) via image recognition to obtain true single cell arrays. The figures of merit of the customized and optimized setup will be presented. In a proof of concept experiment we investigated the trace elemental fingerprint of THP-1 cells by LA-ICP-TOF-MS (Analyte G2, Teledyne Cetac; icpTOF, TOFWERK) and quantified two metal cell dyes, mDOTA-Ho (CheMatech, Dijon), and Ir-DNA intercalator (Fluidigm, San Francisco). For that, matrix matched calibration standards after Wang et al. were successfully prepared using the same arraying system. We believe that this novel approach opens new ways for automated quantitative single cell LA-ICP-MS.
In chemical elements with three or more stable isotopes, mass-dependent stable isotope fractionation yields correlated isotope ratios, m2/m1 and m3/m1. In three-isotope space, i.e. in a δ’m2/δ’m1 vs. δ’m3/δ’m1 plot, data align along a slope θ, the so called ‘triple isotope fractionation exponent’ that scales the two isotope ratios. Theoretical calculations predict small differences in θ for kinetic- and equilibrium isotope fractionation (Young et al. 2002) and thus the precise measurement of θ allows constraining the reaction mechanism. However, due to an apparent lack of precision of stable isotope analysis by MC-ICP-MS, θ is merely used as analytical quality control, i.e. for demonstration that samples and standards plot within their analytical precision in the range of theoretical θ-values originating in δ-zero.
We show how θ can be determined precisely enough by MC-ICP-MS to distinguish kinetic- and equilibrium isotope fractionation, even when isotopic differences between samples are low. For low magnitudes of isotope fractionation, we exploit new, isotopically fractionated isotope standard materials (Vogl et al. 2016). We determine quality norms regarding interferences and measurement conditions to warrant trueness and to maximize precision. We exemplary explore the measurement of the three-isotope composition of Mg stable isotopes, budget the uncertainty of θ-values, and report the first θ-values of carbonate-water pairs and bioapatite. Our measurement approach adds a new dimension to isotope data beyond the δ-scale that has a high potential to reveal different modes of (bio)mineral precipitation in the sedimentary and biological record and thus to contribute solving conundrums in the Earth and Life Sciences.
Mass spectrometric methods (MC-ICP-MS and TIMS) are without doubt the working horse of stable isotope analysis. However, drawbacks of these methods include the high costs for instruments and their operation, experienced operators and elaborate chromatographic sample preparation which are time consuming.
We propose a lower-cost and faster optical alternative for the analysis of isotope ratios of selected elements: high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Stable isotope amount compositions of boron (B) and magnesium (Mg) were determined based on the absorption spectra of in-situ generated mono-hydrides and halide (MH and MX) using graphite furnace HR-CS-MAS. The use of a modular simultaneous echelle spectrograph (MOSES) helps to find the maximal isotope shift in the diatomic molecular spectra produced in a graphite furnace by using isotopic spike solutions. Isotopes of boron (10B and 11B) were studied via their hydrides for the electronic transition X 1Σ+ → A 1Π. The spectrum of a given sample is a linear combination of the 10BH molecule and its isotopologue 11BH. Therefore, the isotopic composition of samples can be calculated by a partial least square regression (PLS). For this, a spectral library was built by using samples and spikes with known isotope composition. Boron isotope ratios measured by HR-CS-MAS are identical with those measured by mass spectrometric methods at the 0.15 ‰ level. Similar results were obtained for a multiple isotope system like Mg (24Mg, 25Mg, and 26Mg), where isotope shifts of their isotopologues can be resolved in the MgF molecule for the electronic transition X 2Σ → A 2 Πi. The extension of this methodology to other elements like Li, Ca, Cu, and Sr is discussed.
In der klinischen Diagnostik werden für zytometrische Messverfahren bereits eine Reihe von Reagenzien eingesetzt zur Markierung von Antikörper eingesetzt, um die Detektion von Biomarkern mittels Fluoreszenz- oder Flugzeitmassenspektrometrie zu ermöglichen.
Seit kurzem ist auch eine Imaging Mass Cytometry Kombination direkt erhältlich, wodurch der Nachweis von Biomarkern in Gewebeschnitten erreicht werden kann. Dazu wird eine Kopplung von Laser Ablation und induktiv gekoppeltem Plasma Massenspektrometrie eingesetzt, wobei ähnlich der Massenzytometrie, zuvor Antikörper mit Metallen markiert, und im Anschluss mit dem Gewebeschnitt inkubiert werden. Durch die hohe Ortsauflösung können die Biomarker lokalisiert, und zukünftig vielleicht auch quantifiziert werden.
Insbesondere Lanthanide eignen sich als Markierungsmetalle, da sie einen niedrigen Untergrund und chemisch ähnliches Verhalten zueinander aufweisen. Allein durch diese Elemente können bereits etwa 15 Parameter unterschieden werden, was durch isotopenreine Standards weiter gesteigert werden kann.
Vom Markierungsgrad abhängig werden unterschiedlich viele Metalle am Antikörper gebunden, und beeinflussen so die Sichtbarkeit im ICP-MS. Nanopartikel könnten daher eine deutliche Steigerung der Sensitivität bewirken. GdVO4 Nanokristalle scheinen bisher sehr vielversprechend und bieten neben multiparametrischen Anwendungen auch Multimodalität.
Die Synthese der Nanokristalle zeigte hohe Homogenität und Reproduzierbarkeit in Partikelgröße in der Zusammensetzung. Ein erstes Experiment mit einer Zellkultur konnte bereits die effiziente Markierung der Zellen unter Beweis stellen, wobei durch hohe Signalstärke auch subzelluläre Auflösung in der LA-ICP-MS erreicht werden konnte.
Small variations in the isotopic composition of some elements have been used as proof of provenance of mineral and biological samples, to describe geological processes, and to estimate a contamination source. Routinely, isotope compositions are measured by mass spectrometry; the working horse of the isotope analysis. However, mass spectrometric methods are expensive, time-consuming and they require a high qualified analyst.
Here, an alternative faster and low-cost optical method for isotope ratio determination is investigated: high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Stable isotope amount composition of X = Li, B, Mg, Ca and Sr have been determined by monitoring the absorption spectra of their in situ generated hydrides (XH) in graphite furnace HR-CS-MAS. For example, the system of two stable isotopes of boron (10B and 11B) was studied via its hydride for the electronic transition X1Σ+ → A1Π (Fig. 1a). The spectrum of a given sample is a linear combination of the 10BH molecule and its isotopologue 11BH. Therefore, isotopic composition of samples and reference materials are calculated by a partial least square regression (PLS). For this, a spectral library is built by using samples with known isotope composition. Results are metrologically compatible with those reported by mass spectrometric methods. [1] Similar results are obtained for n isotope systems like Mg (24Mg, 25Mg, and 26Mg), where isotope shift of their isotopologues can be resolved as shown in Fig.1 b. The extension of this methodology to other elements like Li, Ca and Sr is discussed [2].
References:
[1] C. Abad, S. Florek, H. Becker-Ross, M.-D. Huang, H.-J. Heinrich, S. Recknagel, J. Vogl, N. Jakubowski, U. Panne, Determination of boron isotope ratios by high-resolution continuum source molecular absorption spectrometry using graphite furnace vaporizers, Spectrochim. Acta, Part B, 136 (2017) 116-122.
[2] C. Abad et al., unpublished results, 2018.
Following fluorinated drugs by molecular absorption spectrometry – from cancer cells to body fluids
(2018)
Fluorine has been widely introduced into pharmaceutical drugs. Due to the high C-F bond strength, a single atom substitution with fluorine produces drastic desirable and tunable changes in the molecular properties. However, the clinical monitoring of these drugs is not straightforward.
Organofluorine compounds are elusive for a non-targeted analysis; a significant problem in fluorine determination is the lack of suitable detection techniques. Standard atomic absorption and emission spectrometers cannot access fluorine, because their resonance lines lie in the VUV spectral range below 100 nm. In the case of conventional inductively coupled argon plasmas (ICP), the plasma energy is too low to generate a significant population of excited fluorine atoms. Recently, our group introduces high-resolution continuum source absorption spectrometry (HR-CS MAS) as a new way for the indirect monitoring of fluorinated compounds. Main benefits of HR-CS-MAS includes low limits of detection, complete analyte recovery, simple to no sample preparation, and short time analysis.
Common approaches to improve the optical properties of semiconductor quantum dots and lanthanide doped nanophosphors present core/shell structures as radiationless deactivation at the particle surface is usually the main energy loss mechanism. This has led to increasingly sophisticated particle architectures using multishell systems with shells of different chemical composition and thickness and initiated an increasing number of quantitative spectroscopic studies focusing on the key performance parameter photoluminescence quantum yield to identify optimum particle structures. This is particularly challenging in the long wavelength region > 1000 nm and for nonlinear emitters like upconversion nanocrystals. Here, we present suitable absolute methods to quantify the photoluminescence of these different emitters in the vis/NIR/IR and as function of excitation power density and underline the impact of such measurements on a profound mechanistic understanding of the nonradiative deactivation pathways in semiconductor and upconversion nanocrystals of different size and particle architecture in different environments.
Molecularly Imprinted Polymers with Integrated Fluorescence as Versatile Biomimetic Sensing Matrices
(2018)
Molecularly imprinted polymers (MIPs) are an established, versatile and high-performance matrix for the selective separation or enrichment of (bio)chemical species, especially small molecules of biochemical or environmental relevance. MIPs are prepared through the polymerization of a mixture of functional monomers and cross-linkers in the presence of the template with subsequent extraction of the latter. Conceptionally, this process can be seen as mimicking in a strongly accelerated, though single-step manner a biological process such as antibody formation. Because the resulting MIPs contain cavities in their matrix that are complementary in size, shape and electronic/ electrostatic or hydrogen bonding demand to the imprinted target molecule or template, these polymers are frequently termed “artificial antibodies”. Compared to natural antibodies, they are chemically and physically much more robust. Regarding sensitivity and selectivity, however, there is still a gap to bridge before MIPs can fully compete with antibodies.
Another favorable aspect that distinguishes MIPs from antibodies is that they can be endowed with an explicit function, allowing the use of MIPs in applications that require more than only an efficient binder. For instance, if specifically designed and polymerizable fluorescent indicators are integrated as functional monomers into a MIP, direct fluorescence sensing can be accomplished. Because MIPs can be prepared in a variety of different formats, their combination with miniaturized or other specific analytical techniques or sensory devices is possible, especially when the transduction mode is light. This presentation will introduce basic design considerations, challenges, limitations and the potential that lies with such sensor materials with some recent examples of our group, targeting various organic oxoanions as analytes.
Contamination of natural bodies of water with oil and lubricants (or generally, hydrocarbon derivatives such as petrol, fuel and others) is a commonly found phenomenon around the world due to the extensive production, transfer and use of fossil fuels. The timely identification of these contaminants is of utmost importance, since they directly affect water quality and represent a risk for wildlife and human health even in trace amounts.
In this work, we develop a simple system for the on-field detection of total petroleum hydrocarbons (TPH) in water and soil, the "Spectrocube". The test is based on the measurement of the fluorescence signal emitted by the molecular rotor 4-DNS-OH dye. This dye is embedded in a hydrophobic polymeric matrix (PVDF), avoiding interactions of water with the dye and providing a robust support for use in test-strip fashion. The test-strip’s fluorescence intensity increases linearly at low concentrations of TPH, reaching a saturation value at higher concentrations.
For excitation and evaluation of the test-strip fluorescence, a simple miniature optical system was designed. The system works semi-quantitatively as solvent-free TPH detection kit, as well as quantitatively when using a simple cyclopentane extraction step. To simplify the fluorescence read-out, the device is coupled to a tablet computer via Bluetooth, running a self-programmed software ("app").
Nanoparticles (NPs) have found a wide range of applications in research and industry. Thereby the interaction of NPs with biological systems like cells has become a major field of interest, ranging from medical applications to nanotoxicology. Size, shape and surface modification of the nanomaterials determine the uptake rate and pathway into the cells, and therefore impact specific cell components and processes.
In recent years, elemental imaging of biological samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is gaining more and more importance. Improvements concerning both spatial resolution (down to 1 µm) and signal-to-background ratio due to low-dispersion LA chambers make LA-ICP-MS particularly interesting for single cell analysis.
Here LA-ICP-MS was applied for the imaging of individual cells to study the uptake and intracellular processing of metal-containing nanostructures. The cells were incubated with different NPs under varying experimental conditions and afterwards fixed with para-formaldehyde and dried for LA analysis. High-spatial resolution LA-ICP-MS was achieved by careful optimisation of the laser ablation parameters.
Our findings show, that LA-ICP-MS is applicable to localize NP aggregates within cellular compartments. The uptake efficiency depends strongly on the physicochemical properties of the nanostructures as well as on the incubation conditions like concentration and incubation time.
The results demonstrate the potential of LA-ICP-MS providing insight into nanoparticle-cell interaction dependent on experimental parameters.
Statistic process control as well as process capability demand for calibrated determination of layer thicknesses in various industries, e.g. automotive, aerospace, microelectronics manufacturing. Calibration requires well know and well characterized samples. A calibration laboratory accredited according to DIN EN ISO 17025 has the objective to distribute standards traceable to SI units to industrial laboratories for quality control of manufacturing of various products. Especially, the thickness determination of thin metallic coatings e.g. from galvanic processes or layer deposition using X-Ray Fluorescence can be significantly improved by customized calibration samples. This is essential as the measurement uncertainty directly correlates to the capability performing reliable control of processes with high yield. For calibration laboratories, the validation of results using round robins and the direct comparison to national metrology institutes is a prerequisite to demonstrate the competence to perform calibration services.
In this paper a strategy to obtain traceability and validation for thin alloy layers as well as first results are presented. The combined use of the accredited method for determination of mass per area from measurement of mass and area combined with standard free X-Ray Fluorescence as well as chemical analysis of dissolved samples with thin layers is deployed for material systems as NixZn1-x as well as NixP1-x. The obtained results are compared to reference free X-Ray Fluorescence at the BESSY II laboratories of Physikalisch-Technische Bundesanstalt. An excellent agreement of the obtained measured values as mass per unit area and alloy concentrations from the different applied methods within the measurement uncertainty was observed for NixP1-x showing the successful performed traceability of the calibration samples to SI units in combination with a validation of results by national metrology institutes and the round robin approach.
Die ehemals wegen komplexer Technik und vergleichsweise hohen Wartungskosten beim Anwender ungeliebte Prozessanalysentechnik (PAT) erfährt sich mittlerweile immer mehr als etablierender Bereich mit einem großen Zuwachs und Dynamik. Die Prozesskontrolle und -steuerung über physikalische Kenngrößen wie Druck und Temperatur lässt eine weitere Optimierung der Anlagen kaum mehr zu. Nur mittels stoffspezifischer Analysen lassen sich Rohstoffschwankungen, Ausbeuten und Energieeinsatz konsequent optimieren.
Der systematische Einsatz der Prozessanalysentechnik verändert Prozesse und Produktionsumgebungen und hat damit die Chance, Kernstück dezentral automatisierter Produktionseinheiten zu werden. Ein neuer Arbeitskreis der NAMUR AK 3.7 „Smarte Sensorik, Aktorik und Kommunikation“ wird diesem verstärkt Rechnung tragen. Es werden reale Anwendungsbeispiele aufgezeigt, die eine schnelle Amortisation von PAT im Prozess untermauern.
To keep up with emerging mycotoxins and their transformation products fast and reliable toxicity tests are needed. Toxicity testing of mycotoxins is carried out usually by performing in vitro assays or is evaluated by using laboratory animals like mice, rats or chicken in in vivo studies.
Settled between classical in vitro approaches and in vivo studies with higher animals are tests with the nematode Caenorhabditis elegans. Since Sydney Brenner described 1974 the cultivation and handling of C. elegans, this worm is widely used as model organism in developmental biology and neurology. Due to many benefits like easy and cheap cultivation, a completely sequenced genome and short generation time, it also plays an important role in toxicological research. Finally, the high number of conserved genes between human and C. elegans make the worm an ideal candidate for toxicological investigations.
In this study we used C. elegans to assess the toxic effects of the relevant food mycotoxin citrinin (CIT), the mycoestrogen zearalenone (ZEN) and the modified mycotoxin ZEN-14-sulfate (ZEN-14-S) on different lifetable parameters including reproduction, thermal and oxidative stress tolerance and lifespan. All tested mycotoxins significantly decreased the amount of offspring. In case of ZEN and CIT also significant negative effects on stress tolerance and lifespan were observed compared to the control group.
Moreover, metabolization of mycotoxins in the worms was investigated by using LC MS/MS. Extraction of the worms treated 5 days with mycotoxin-containing and UVC-killed bacteria showed metabolization of ZEN to α-ZEL and β-ZEL (ZEL = zearalenol, ratio about 3:2). ZEN 14-S was reduced to ZEL 14-S and CIT was metabolized to mono hydroxylated CIT.
An overview about different analytical approaches will be presented of how to detect metals in individual biological cells by use of ICP-MS. For this purpose, we are using different sample introduction systems for ICP-MS for detection, imaging and quantification of metals at cellular levels.
By use of laser ablation, we have studied the up-take by and distribution of nanoparticles in single cells. Recently we have developed staining techniques to measure protein and DNA content of cells and identifying the cell status by immunoassays using metal-tagging of antibodies. New research based on cell arrays will be shortly discussed.
Using pneumatic nebulization and microdroplet generation, we have also studied the up-take of nanoparticles and toxic metals as well as essential elements in single cells using different ICP-MS mass spectrometric concepts (sector field instrument, triple-quad instrument, time of flight (CyTOF) instrument).
The different ICP-MS based methods will be compared concerning their analytical figures of merit and their strengths and weaknesses will be evaluated.
We are using LA-ICP-MS to quantify metals in biological cells and thin cuts of tissues from varies organs. Different applications will be presented to demonstrate the state of the art of bioimaging to visualize the elemental distribution pattern in soft bio-materials (tissue, single cells) of metals, metal containing stains and metal-tagged antibodies. For this purpose, different strategies for metal tagging will be presented and will be compared in terms of analytical figures of merit. First applications for detection of biomarkers in animal and human tissue samples will be presented.
In a first example, we have applied LA-ICP-MS to visualize the local distribution of proteins, which are used as bio-markers for neurodegenerative diseases. For this purpose, brain tissues from mice experiments have been stained by metal-tagged antibodies. House-keeping proteins have been investigated as internal cellular standards. Additionally, ink-jet printing of metal doped inks onto the surface of tissue samples has been applied for drift corrections and quantification. Validation of our results are achieved in comparison to immune-histochemical staining and optical microscopy.
In a second example, we used specific metal-tagged antibodies for detection of biomarker specific for prostate cancer. For this purpose, micro tissue arrays are incubated with metal-tagged antibodies for bioimaging of samples from many patients using simultaneous detection of all relevant biomarkers and their tags.
For improvement of sensitivity in the next example application nanoparticle tagged antibodies for detection of metallothionines in eye lens tissue samples will be discussed.
Recently we have used our tagging and staining strategies to determine the cell cycle of single cells, which is of future interest for toxicological studies.
Finally, future trends in elemental microscopy and mass cytometry imaging will be discussed.
Die Spurenfeuchte ist eine wichtige Messgröße bei der Qualitätsbeurteilung von technischen und medizinischen Gasen und muss daher zuverlässig gemessen werden. Der Spurenbereich ist definiert durch einen Wasserdampf-Stoffmengenanteil kleiner als 2600 µmol/mol bzw. einer Frostpunkttemperatur kleiner -10 °C. Eine geeignete Methode für die kontinuierliche Spurenfeuchtemessung stellt das Elektrolyseverfahren bzw. coulometrische Messprinzip dar. Bei diesem Prinzip strömt ein feuchtes Gas über eine hygroskopische Phosphorpentoxid-Schicht, welche kontinuierlich Wasserdampf absorbiert. Durch das Anlegen einer Zersetzungsspannung wird das absorbierte Wasser elektrolysiert und der resultierende Elektrolysestrom korreliert zum Feuchtegehalt im Gas. Neben dem Einfluss von unterschiedlichen Gasen auf das Messverfahren, wurde der Einfluss der Druckfeuchte im Druckbereich von 2 bis 15 bar untersucht. Des Weiteren wurde eine neuartige Sensorbeschichtung basierend auf einer ionischen Flüssigkeit getestet und es wurde ein Prototyp für die abgestufte Bestimmung der Wasseraktivität und der Materialfeuchte aufgebaut.
The interaction of nanoparticles (NPs) with cells has become a major field of interest, ranging from medical applications to nanotoxicology. Size, shape and surface modification of the NPs determine the uptake rate and pathway into the cells, and therefore impact specific cell components and processes.
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is an established quantitative multi-elemental analysis and mapping technique. In recent years, it was shown that LA-ICP-MS can provide quantitative as well as distribution information of NPs in cell samples.
Here LA-ICP-MS was applied for the imaging of individual cells to study the uptake and intracellular processing of metal-containing nanostructures. Additionally, the local distribution of naturally occurring elements in cells like P was measured to indicate cell morphology. The cells were incubated with different types of NPs under varying experimental conditions. For LA analysis, the cells were fixed and dried.
Our findings show, that LA-ICP-MS is suitable for the localisation of nanoparticle aggregates within cellular compartments. The studied NPs accumulate in the perinuclear region in the course of intracellular processing, but do not enter the cell nucleus. The uptake efficiency depends strongly on the physicochemical properties of the nanostructures as well as on the incubation conditions like concentration and incubation time.
The results demonstrate the potential of LA-ICP-MS providing insight into NP uptake, intracellular distribution and cell-to-cell variation dependent on experimental parameters.
The departure from the current automation landscape to next generation automation concepts for the process industry has already begun. Smart functions of sensors simplify their use and enable plug-and-play integration, even though they may appear to be more complex at first sight. Monitoring specific information (i.e., “chemical” such as physico-chemical properties, chemical reactions, etc.) is the key to “chemical” process control. Here we introduce our smart online NMR sensor module provided in an explosion proof housing as example.
Due to NMR spectroscopy as an “absolute analytical comparison method”, independent of the matrix, it runs with extremely short set-up times in combination with “modular” spectral models. Such models can simply be built upon pure component NMR spectra within a few hours (i.e., assignment of the NMR signals to the components) instead of tedious calibrations runs. We present a range of approaches for the automated spectra analysis moving from statistical approach, (i.e., Partial Least Squares Regression) to physically motivated spectral models (i.e., Indirect Hard Modelling and Quantum Mechanical calculations).
Based on concentration measurements of reagents and products by the NMR analyzer a continuous production and direct loop process control were successfully realized for several validation runs in a modular industrial pilot plant and compared to conventional analytical methods (HPLC, near infrared spectroscopy). The NMR analyser was developed for an intensified industrial process funded by the EU’s Horizon 2020 research and innovation programme (“Integrated CONtrol and SENsing”, www.consens-spire.eu).
Due to NMR spectroscopy as an “absolute analytical comparison method”, independent of the matrix, it runs with extremely short set-up times in combination with “modular” spectral models. Such models can simply be built upon pure component NMR spectra within a few hours (i.e., assignment of the NMR signals to the components) instead of tedious calibrations runs. We present a range of approaches for the automated spectra analysis moving from statistical approach, (i.e., Partial Least Squares Regression) to physically motivated spectral models (i.e., Indirect Hard Modelling and Quantum Mechanical calculations). The departure from the current automation landscape to next generation automation concepts for the process industry has already begun. Smart functions of sensors simplify their use and enable plug-and-play integration, even though they may appear to be more complex at first sight. Monitoring specific information (i.e., “chemical” such as physico-chemical properties, chemical reactions, etc.) is the key to “chemical” process control. Here we introduce our smart online NMR sensor module provided in an explosion proof housing as example.Based on concentration measurements of reagents and products by the NMR analyzer a continuous production and direct loop process control were successfully realized for several validation runs in a modular industrial pilot plant and compared to conventional analytical methods (HPLC, near infrared spectroscopy). The NMR analyser was developed for an intensified industrial process funded by the EU’s Horizon 2020 research and innovation programme.
The departure from the current automation landscape to next generation automation concepts for the process industry has already begun. Smart functions of sensors simplify their use and enable plug-and-play integration, even though they may appear to be more complex at first sight. Monitoring specific information (i.e., “chemical” such as physico-chemical properties, chemical reactions, etc.) is the key to “chemical” process control. Here we introduce our smart online NMR sensor module provided in an explosion proof housing as example.
Due to NMR spectroscopy as an “absolute analytical comparison method”, independent of the matrix, it runs with extremely short set-up times in combination with “modular” spectral models. Such models can simply be built upon pure component NMR spectra within a few hours (i.e., assignment of the NMR signals to the components) instead of tedious calibrations runs. We present a range of approaches for the automated spectra analysis moving from statistical approach, (i.e., Partial Least Squares Regression) to physically motivated spectral models (i.e., Indirect Hard Modelling and Quantum Mechanical calculations).
Based on concentration measurements of reagents and products by the NMR analyzer a continuous production and direct loop process control were successfully realized for several validation runs in a modular industrial pilot plant and compared to conventional analytical methods (HPLC, near infrared spectroscopy). The NMR analyser was developed for an intensified industrial process funded by the EU’s Horizon 2020 research and innovation programme (“Integrated CONtrol and SENsing”, www.consens-spire.eu).
The departure from the current automation landscape to next generation automation concepts for the process industry has already begun. Smart functions of sensors simplify their use and enable plug-and-play integration, even though they may appear to be more complex at first sight. Monitoring specific information (i.e., “chemical” such as physico-chemical properties, chemical reactions, etc.) is the key to “chemical” process control.
The talk introduces a smart online NMR sensor module provided in an explosion proof housing as example. This sensor was developed for an intensified industrial process (pharmaceutical lithiation reaction step) funded by the EU’s Horizon 2020 research and innovation programme (www.consens-spire.eu). Due to NMR spectroscopy as an “absolute analytical comparison method”, independent of the matrix, it runs with extremely short set-up times in combination with “modular” spectral models. Such models can simply be built upon pure component NMR spectra within a few hours (i.e., assignment of the NMR signals to the components) instead of tedious calibrations runs.
Industry 4.0, IIoT, or Lab 4.0 will enable us to handle more complex processes in shorter time. Intensified production concepts require for adaptive analytical instruments and control technology to realize short set-up times, modular control strategies. They are based on a digitized Laboratory 4.0.
Ultrasound echo is a widely used NDT technique for determining the internal geometry of structures. Reverse-time migration (RTM) has been recently introduced to NDT applications, as an imaging method for ultrasound data, to overcome some of the limitations (e.g. imaging steeply dipping reflector) experienced by the Synthetic Aperture Focusing Technique (SAFT), the most commonly used imaging algorithm for these measurements.
The standard implementation of RTM also experiences some drawbacks caused by its imaging condition, which is based on the zero-lag of the cross-correlation between source and receiver wavefields and generates high-amplitude low-frequency artifacts. Three alternative imaging conditions, developed for seismic data applications, were tested for their ability to provide better images than the standard cross-correlation: illumination compensation, deconvolution and wavefield decomposition. A polyamide specimen was chosen for the simulation of a synthetic experiment and for real data acquisition. The migrations of both synthetic and real data were performed with the software Madagascar. The illumination imaging condition was able to reduce the low-frequency noise and had a good performance in terms of computing time. The deconvolution improved the resolution in the synthetic tests, but did not showed such benefit for the real experiments. Finally, as for the wavefield decomposition, although it presented some advantages in terms of attenuating the low-frequency noise and some unwanted reflections, it was not able to image the internal structure of the polyamide as well as the cross-correlation did. Suggestions on how to improve the cost-effectiveness of the implementation of the deconvolution and wavefield decomposition were presented, as well as possible investigations that could be carried out in the future, in order to obtain better results with those two imaging conditions.
An overview about different analytical approaches will be presented of how to detect metals in individual biological cells by use of ICP-MS. For this purpose, we are using different sample introduction systems for ICP-MS for detection, imaging and quantification of metals at cellular levels.
By use of laser ablation, we have studied the up-take by and distribution of nanoparticles in single cells. Recently we have developed staining techniques to measure protein and DNA content of cells and identifying the cell status by immunoassays using metal-tagging of antibodies. New research based on cell arrays will be shortly discussed.
Using pneumatic nebulization and microdroplet generation, we have also studied the up-take of nanoparticles and toxic metals as well as essential elements in single cells using different ICP-MS mass spectrometric concepts (sector field instrument, triple-quad instrument, time of flight (CyTOF) instrument).
The different ICP-MS based methods will be compared concerning their analytical figures of merit and their strengths and weaknesses will be evaluated.
An overview about different analytical approaches will be presented of how to detect metals in individual biological cells by use of ICP-MS. For this purpose, we are using different sample introduction systems for ICP-MS for detection, imaging and quantification of metals at cellular levels.
By use of laser ablation, we have studied the up-take by and distribution of nanoparticles in single cells. Recently we have developed staining techniques to measure protein and DNA content of cells and identifying the cell status by immunoassays using metal-tagging of antibodies. New research based on cell arrays will be shortly discussed.
Using pneumatic nebulization and microdroplet generation, we have also studied the up-take of nanoparticles and toxic metals as well as essential elements in single cells using different ICP-MS mass spectrometric concepts (sector field instrument, triple-quad instrument, time of flight (CyTOF) instrument).
The different ICP-MS based methods will be compared concerning their analytical figures of merit and their strengths and weaknesses will be evaluated.
Der Vortrag stellt einige aktuelle Herausforderungen für die Prozessanalytik und mögliche Antworten vor.
Gepulste Raman-Spektrometer akkumulieren das Raman-Signal mit Hilfe schneller optischer Schalter im Picosekunden-Bereich, bevor langlebigere Fluoreszenzanregung entsteht. Damit lassen sich stark fluoreszierende Materialien untersuchen, die bislang nicht zugänglich sind. Eine weitere interessante Entwicklung ist etwa die Shifted excitation Raman difference spectroscopy (SERDS) die besonders für biologische Anwendungen interessant ist.
Flexible, modulare Produktionsanlagen stellen einen vielversprechenden Ansatz für die kontinuierliche Produktion von Fein- und Spezialchemikalien dar. In einem EU-Projekt wurde die Feldintegration eines Online-NMR-Sensormoduls als smartes Modul für die Prozesskontrolle vorangebracht. Dieses Modul basiert auf einem kommerziell erhältlichen Niederfeld-NMR-Spektrometer, welche zurzeit für die Anwendung im Laborbereich erhältlich ist. Für die Feldintegration wurde ein ATEX-zertifiziertes, explosionsgeschütztes Gehäuse entwickelt sowie Automationsschemen für den unbeaufsichtigten Betrieb und für die kalibrierfreie spektrale Datenauswertung erstellt.
Eine sehr gut anwendbare analytische Messtechnik zur Kontrolle der elementaren Zusammensetzung von verschiedensten Materialien ist die laserinduzierte Plasmaspektroskopie (LIPS, engl. LIBS - Laser-induced Breakdown Spectroscopy). Bei der LIBS wird ein kurz gepulster Laser auf eine Probe fokussiert, um ein Leuchtplasma zu erzeugen. Das dabei erzeugte Atomemissionsspektrum ermöglicht eine qualitative und quantitative Analyse der Zusammensetzung der Probe bezüglich praktisch aller Elemente des Periodensystems. In einem aktuellen Projekt wird diese Methode neben anderen zur Online-Analyse von Ackerböden für die ortsspezifischer Bewirtschaftung (Precision Agriculture) weiterentwickelt und bewertet.
In der Berliner Sammlung "Manuscripta Americana" befinden sich Fragmente von Bilderhandschriften, die Alexander von Humboldt 1804 in Mexiko erwarb und der Königlichen Bibliothek schenkte. Die in der frühen Kolonialzeit hergestellten verschiedenartigen Codices waren damals schon nicht mehr an den Orten ihrer ursprünglichen Verwendung. Entsprechend ihres Seltenheitswertes gelangten einzelne Schriftstücke seit der Conquista in die Bestände bedeutender Persönlichkeiten. Hierzu fertigte man auch Abschriften oder Kopien an, oder zerstückelte sogar einzelne Blätter, so dass die Darstellungen auf den abgetrennten Fragmenten oft nur zum Teil abgebildet vorliegen.
Um herauszufinden, ob einige Schriftstücke der "Humboldt Codices" in Bezug zu einander stehen, werden die Dokumente, ihre Symbole und Schriftzeichen und das zur Herstellung verwendete Material miteinander verglichen.
Mit den für die Analyse von Manuskripten bewährten Untersuchungsmethoden werden Papier und Farbmittel identifiziert. Hierzu zählen Raman-, FTIR-, Röntgenfluoreszenz- und VIS- Spektroskopie. Charakteristisch für die Herstellung von schriftlichen Dokumenten in der Kolonialzeit von Amerika ist die Verwendung von indigenem Material wie Papier aus Baumrinde und Pflanzenfarben zusammen mit den aus Europa bekannten Materialien. Geklärt wird, inwieweit neben den bekanntesten Farbstoffen wie Cochenille, Mayablau oder Mischungen mit Tonmineralen auch mineralische Pigmente zum Einsatz kamen.
Vorgestellt werden die auf Tafel 36 in den "Vues des Cordillères et Monuments des Peuples Indigènes de l`Amerique, Voyage de Humboldt et Bonpland" abgebildeten Fragmente. Die hier von Humboldt vorgenommene Zusammenstellung wird mit der Farbpalette der in Berlin archivierten originalen Schriftstücke verglichen. Die Interpretation der Ergebnisse gibt einen Hinweis auf die Zuordnung oder auch Zusammengehörigkeit dieser einzigartigen Dokumente amerikanischer Geschichte. Hierbei wird die Frage aufgeworfen, inwiefern davon auszugehen ist, dass diese mit weiteren Fragmenten in Verbindung gebracht werden können, was für die Beleuchtung der kulturhistorischen Zusammenhänge von großer Bedeutung ist.
The common characterization and identification of pollen is a time-consuming task that mainly relies on microscopic determination of the genus-specific pollen morphology. A variety of spectroscopic and spectrometric approaches have been proposed to develop a fast and reliable pollen identification using specific molecular information. Amongst them, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) shows a high potential for the successful investigation of such complex biological samples. Based on optimized MALDI sample preparation using conductive carbon tape, the application of multivariate statistics (e.g. principal components analysis, PCA) yields an enormous improvement concerning taxonomic classification of pollen species compared to common microscopic techniques.
Since multivariate evaluation of the recorded mass spectra is of vital importance for classification, it’s helpful to implement the applied sequence of standard Matlab functions into a graphical user interface (GUI). In this presentation, a stand-alone application (GUI) is shown, which provides multiple functions to perform fast multivariate analysis on multiple datasets. The use of a GUI enables a first overview on the measured dataset, conducts spectral pretreatment and can give classification information based on HCA and PCA evaluation. Moreover, it can be used to improve fast spectral classification and supports the development of a simple routine method to identify pollen based on mass spectrometry.
Analyse des Tausalzeintrages in Fahrbahndeckenbetone im Kontext der Alkali-Kieselsäure-Reaktion
(2018)
In den letzten Jahren sind im deutschen Bundesautobahnnetz (BAB-Netz) vermehrt AKR-Schäden an Betonfahrbahndecken aufgetreten, die zum Teil zu einer Halbierung ihrer geplanten Nutzungsdauer von 30 Jahren führte. Ursächlich hierfür ist die Verwendung alkaliempfindlicher Gesteinskörnung, die bei gleichzeitiger Anwesenheit von Wasser infolge der Exposition der Fahrbahndecke und dem alkalischen Milieu durch den Einsatz alkalireicher Portlandzemente bei der Betonherstellung zu einer Alkali-Kieselsäure-Reaktion (AKR) führt. Zusätzlich wird der AKR-Schädigungsprozess in Betonfahrbahndecken durch den externen Tausalzeintrag (primär NaCl) im Winter begünstigt. Vor diesem Hintergrund kommt der Ermittlung des Tausalzeintrags in den Fahrbahndeckenbeton eine große Bedeutung zu. Die Analyse des Tausalzeintrags erfolgte bisher ausschließlich nasschemisch an gemahlenen Bohrkernsegmenten. Nachteilig ist hierbei die fehlende differenzierte Betrachtung des Natriumgehaltes im Zementstein und in der Gesteinskörnung. Der alternative Einsatz von LIBS (Laser-induced breakdown spectroscopy) eröffnet in diesem Kontext neue Möglichkeiten. So wird in diesem Beitrag an Hand von Bohrkernen aus einem AKR-geschädigten BAB-Abschnitt exemplarisch die Vorgehensweise bei der LIBS-Analyse zur Ermittlung der Na- und interagierenden Cl-Verteilung an vertikalen Schnittflächen des Bohrkerns aufgezeigt. Da der Tausalzeintrag primär über den Zementstein erfolgt, wurde der verfälschende Na-Grundgehalt der Gesteinskörnung mittels Zementsteinkriteriums (Nutzung unterschiedlichen Ca-Gehalts in Zementstein und Gesteinskörnung) eliminiert. Vergleichend durchgeführte Cl-Mappings mit Mikroröntgenfluoreszenzanalyse (MRFA) belegen die Güte der durchgeführten LIBS-Messungen.
Aber auch bei der Verifizierung der Übertragbarkeit der Ergebnisse der zum Ausschluss reaktiver Gesteinskörnung bei Neubau und Erneuerung im BAB-Netz eingesetzten Performanceprüfungen mit externem Alkalieintrag auf Praxisverhältnisse hat sich das LIBSVerfahren bewährt. So wurde festgestellt, dass die mit NaCl-Lösung beaufschlagten Laborprüfkörper aus einem repräsentativen Fahrbahndeckenbeton bei der Klimawechsellagerung (KWL) über ihre gesamte Höhe von 10 cm einen Eintrag von Na und Cl erfahren. Weiterhin konnte im Gegensatz zu bisherigen Annahmen erstmals mit LIBS und Nasschemie gezeigt werden, dass die Frost-Tauwechsel-Phase bei der KWL zu keinem erhöhten Tausalzeintrag führt.
In chemical elements with three or more stable isotopes, mass-dependent stable isotope fractionation is expressed by co-varying isotope ratios. In the three-isotope space ((δ’m2/δ’m1)/(( δ’m3/δ’m1)) these plot along a line with a slope (β), the so called ‘terrestrial fractionation line’. This partitioning of stable isotopes results from both kinetic and equilibrium reactions that are characterized by specific β-values.
For the natural range of isotope ratios of ‘novel’ stable isotope systems such as Si, Mg, Fe, Zn, Cu this information cannot be accessed because samples fall close to the delta-zero standard where the current measurement precision is too low to resolve small differences in β. We present a new approach to resolve deviations from a reference slope β by standard-sample bracketing against material offset from the natural range. We use this approach to explore the isotope fractionation mechanism in the mammalian food web. We have analyzed Mg stable isotope ratios in bone bioapatite of herbivore, omnivore and carnivore mammals. Positive shifts in δ26/24Mg along the trophic chain (from herbivore to carnivore) together with β= 0.513 suggest the presence of two isotope fractionation mechanisms operating during biomineralization. While positive shifts in δ26/24Mg are in favor of equilibrium isotope fractionation process, the proximity of β to the theoretically calculated β(kinetic) of typically 0.511 suggests the presence of a second component that fractionates stable isotopes kinetically. The herein presented approach is applicable to any element with 3+ stable isotopes analyzed by multi-collector inductively coupled plasma mass spectrometry.
This is the first time that PE frits were used to quantify sulfur in copper and its alloys by isotope dilution combined with LA-ICP-MS: an alternative approach for sample preparation. The following properties of the PE frit meet the requirements for isotope dilution LA-ICPMS:: porous material, thermo plastic (melting point >100oC), chemical resistance (nitric acid >70%) and high adsorption efficiency. The breakthrough, however, as a support material, especially when comparing the PE frit with other materials such gelatin or sodium silicate is the low blank, which is only two times of the gas flow blank (2.3-4.0 x 104 cps). Additionally, the porosity of the frit was considered, as it directly affects the adsorption efficiency for the sample solution, which is present in the cavities of the frit.
Adsorption efficiency was studied by depositing sulfur standards with varying sulfur amounts (0, 2, 5, 10, 20, 40 and 80 µg S) on the frits. The remaining sulfur which was not absorbed by the frit was rinsed off and was measured by ICP-MS. This indirect method shows that more than 99.5 % of the loaded sulfur was absorbed by the frit. Such high absorption efficiency is completely sufficient for a support material to be used in LA-ICP-IDMS. The so prepared frits whith increasing sulfur amount were measured by LA-ICP-MS showing a good linearity between 0 µg S and 40 µg S whit a correlation coefficient r2 of 0.9987 and sensitivy of 3.4x104 cpsµg-1 for 32S.
Three copper reference materials produced by BAM were selected to develop and validate the LA-ICP-IDMS procedure. The IDMS technique was applied to these samples as follows: the samples were spiked, dissolved, digested and then the digest was adsorbed on the frits.
Summary: A screening test for potential emissions of volatile organic compounds (VOC) was run on different thermoplastic filaments used for 3D printing. The method of direct thermal desorption was used to simulate the high temperatures during the 3D printing process and to identify the main compounds emitted from the filaments. A large number of unexpected compounds were detected that might affect the user’s health and have an impact on indoor air chemistry.
Introduction: The use of desktop 3D printers is increasing. Compared to other devices with known emissions, e.g. laser printers, there is still a lack of information on possible emissions of VOC and ultrafine particles during operation and the effect on indoor air quality. Most of the commercially available desktop 3D printers operate with a molten polymer deposition. For this process a solid thermoplastic filament is heated in an extrusion nozzle. Most filaments for desktop 3D printers use either acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) as filament. Alternatives are polyvinyl alcohol (PVA) or polycarbonate (PC).
Method: Eight different thermoplastic filaments for 3D printers were analysed by direct thermal desorption followed by GC-MS identification of the emitted substances. Direct thermal desorption was done by desorbing 5 mg of the feedstock for 1 minute at a temperature of 210°C. This is an average temperature for 3D printing with thermoplastic filaments.
Results and conclusions: The comparison of the 4 different filament groups showed the highest overall emissions from ABS, followed by PLA, PC and PVA. Filament ABS 2 emitted mainly SVOCs and triphenyl phosphate, the latter has the highest emission for a single compound from all evaluated filaments.
Thermoplastic filaments are a new source of VOC emissions due to the high temperatures associated with 3D printing, which can reach up to 270°C. Some of the detected compounds like lactic acid, lactide and bisphenol A have never been described before in the indoor environment. Additionally some of the main substances could not be identified and some others might have the potential to affect the indoor air chemistry.
The appearance of some newly detected compounds raises concerns about potential health effects for the users of 3D printers at home.
Non-invasive Cereal Analysis by GC-MS detection of Trichodiene as a Volatile Mycotoxin Biomarker
(2018)
Due to the increasing consumption of cereals worldwide, the monitoring of growth, storage and processing is becoming more and more crucial. Particularly when stored, infested grains breed fungal clusters (“hot spots”) in which mycotoxins greatly exceed allowed maximum levels. Because of their unpredictable presence, current sample drawing and procedures for mycotoxin analysis represent a complex challenge for operators, involving invasive and cost intensive steps.
Therefore, new time- and labour-saving mycotoxin control methods including sampling and analysis steps are needed. A possible approach is the non-invasive analysis of the homogeneous gas phase above the crops, instead of analyzing random samples. However, this procedure requires microbial volatile organic compounds (MVOC´s) being released by the samples and representing the present mycotoxins. Previous investigations revealed trichodiene to be a precursor in trichothecenes biosynthesis – one of the largest mycotoxin groups with over 180 compounds. Due to its non-functionalized sesquiterpene structure, trichodiene has already been quantified using Headspace GC-MS methods (for instance). Thereby, it can possibly be used as a biomarker for trichothecene contamination in foodstuff.
However, further investigations are necessary. The correlation between trichodiene concentration in the gas phase and trichothecenes mass fraction in the sample must be examined closely to draw conclusions about the exact trichothecene content within samples. Realizing this idea, would widely extend the applicability of trichodiene and enormously simplify trichothecene quantification. Hence, this first step of an ongoing study aims to develop a laboratory reference method using trichodiene as volatile biomarker to quantify trichothecenes in cereals. Static headspace and SPME-enrichment coupled to gas chromatography with mass spectrometry (GC-MS) were employed. In a second step, this reference method is intended to validate new approaches for fast on-site screening of trichodiene in cereals.
Heritage Lecture
(2018)
After finishing my diploma thesis in plasma physics in 1981, I dreamt of a future in a research lab to develop novel fusion reactors for energy production or to study universal plasmas and their emission in the cosmos. This dream never became real, however I found my first job in a team to build up a new museum dedicated to “Energy”, and this first part of my career was already finished after a year, because the funding was not extended. So, I found immediately a new job as a young scientist in the institute for analytical sciences (originally ISAS: Institute for Plasmachemistry and Applied Spectroscopy) in 1982 to develop novel plasma ion sources for inorganic mass spectrometry. The first source of interest was based on a glow discharge for direct analysis of conducting solids (technically supported by Finnigan MAT, Bremen). Here I adopted the design of the Grimm type discharge for the first time, which was well known in optical emission spectroscopy, and coupled it to a quadrupole mass analyzer. The advantage of this design was that flat craters are produced by sputtering which made this source very powerful for in-depth analysis of technical layers. This then became the topic of my PhD, which was not originally planned, and I had to learn a lot about surface analysis. However, since the first project was too successful we established a small team (in cooperation with Jose Broekaert - an expert in ICP-OES) which started with the development of our own inductively coupled plasma ion source in 1986 coupled to a quadrupole and in 1989 to a sector field mass spectrometer (funded by the Minister of Science and Technology; again in cooperation with Finnigan MAT). The latter device was launched to the market in 1993 as the Element 1.
The second decade of my career was still related to instrumental development but mainly of glow discharge sources. In an EU funded project first an automated glow discharge sector field instrument was developed where the Grimm type geometry was combined with a fast flow concept (in cooperation with Volker Hoffmann at IFW in Dresden). This was done in cooperation with VG (which became later a part of Thermo Fisher Scientific together with Finnigan MAT), so that it is not surprising that this concept for the Element GD. This project was later continued in the third phase of my career, again funded by the EU and in cooperation with the group of Alfredo Sanz-Medel (Rosario Pereiro and Jorge Pisonero), to develop a fast flow, but now rf-powered GD ion source in combination with a time-of-flight mass spectrometer, which was later launched to the market commercially by Horiba Jobin Yvon (France) for in-depth profiling of thin layers even of non-conducting materials.
In the first decade of my career I started to study already “analytical chemistry” from the scratch because the instruments developed have been applied now for direct analysis of solid materials, technical layers and environmental samples. In case of environmental applications our ICP-MS (the quadrupole and the sector field instrument) was coupled with separation techniques, so that this period of instrumental development was dominated in the second decade by development of high efficiency sample introduction systems in combination with speciation studies of Pt group elements, arsenic, selenium and phosphorus (in DNA and phosphorylated proteins), Ni and Cr. Additionally, we continued with the analysis of solid ceramic materials (Al2O3, SiC, SiN) and ambient air-born particles. At the end of the second decade we complemented our instrumental pool by a collision and reaction cell instrument in cooperation with Micromass and used this instrument for speciation studies of peptides and proteins and demonstrated that by ICP-HEX-MS quantitative proteomics is feasible. Therefore, we more and more focused in the following years on metalloproteins and published a famous paper on “Metallobiomolecules: The basis of life, the challenge of atomic spectroscopy” (together with Luc Moens and Ryszard Lobinski). For detection of metalloproteins we applied typical workflows of biochemistry and proteomics, for which I had to extend my knowledge about biochemistry and proteomics. As a new analytical tool, we used a homemade laser ablation cell for sample introduction of metalloproteins after their separation by gel electrophoresis and extended this work by applying metal-tagging of antibodies for Western blot assays. For this purpose, proteins were separated in SDS-PAGE and electroblotted onto membranes. Specific detection of proteins even not containing any metal could be performed by laser ablation ICP-MS using the metal tagged antibodies for indirect detection. This research was interrupted in 2009 by a movement from ISAS (where atomic spectroscopy was declining) to BAM (the Federal Institute for Materials Research and Testing, Berlin) where this research direction was fostered. The experience we achieved at ISAS in the previously mentioned projects were now used here at BAM in the fourth decade for materials research and the development of a quantitative elemental microscope with cellular resolution. So, at the end of my career I am trying to apply all my knowledge and expertise to develop analytical methods and to apply multimodal spectroscopies to decipher the construction code of the cellular machinery, which is the most precise and complex machinery I have ever seen. If we were able to understand how this machinery works, we can better diagnose and treat a malfunction in case of the development of a disease.
Finally, I can conclude that lifelong learning starts before school but does not end at the end of this lecture. It looks like this heritage lecture will be focused on my career only, but this is not the case because some highlights of my career will be used to illustrate a few universal principles: how to have fun, how to find friends and how this all leads to an increase of joy and joy is the basis of new ideas (which must not always be related to your profession) and novel ideas are essential for a successful and satisfying career. So, this heritage lecture wants to answer the most important question of a life which was dedicated to plasma spectrochemistry:
1) Is it possible - at all - to have fun in this research direction?
2) Can we learn already today what we need tomorrow?
3) How can we still realize our scientific dreams of cutting edge research in times of cutting budgets? Which automatically leads to the next question:
4) Is necessity the mother of invention?
All questions will be answered! Controversial discussions (for angry or disappointed colleagues) will be stimulated and my visions of future research (for students and postdocs) and instrumental developments (for manufacturer) will be presented. Finally, conclusions will be drawn by the auditorium (everybody) and thanks will be given to Ramon Barnes (by me) already in advance!
Heritage Lecture
(2018)
After finishing my diploma thesis in plasma physics in 1981, I dreamt of a future in a research lab to develop novel fusion reactors for energy production or to study universal plasmas and their emission in the cosmos. This dream never became real, however I found my first job in a team to build up a new museum dedicated to “Energy”, and this first part of my career was already finished after a year, because the funding was not extended. So, I found immediately a new job as a young scientist in the institute for analytical sciences (originally ISAS: Institute for Plasmachemistry and Applied Spectroscopy) in 1982 to develop novel plasma ion sources for inorganic mass spectrometry. The first source of interest was based on a glow discharge for direct analysis of conducting solids (technically supported by Finnigan MAT, Bremen). Here I adopted the design of the Grimm type discharge for the first time, which was well known in optical emission spectroscopy, and coupled it to a quadrupole mass analyzer. The advantage of this design was that flat craters are produced by sputtering which made this source very powerful for in-depth analysis of technical layers. This then became the topic of my PhD, which was not originally planned, and I had to learn a lot about surface analysis. However, since the first project was too successful we established a small team (in cooperation with Jose Broekaert - an expert in ICP-OES) which started with the development of our own inductively coupled plasma ion source in 1986 coupled to a quadrupole and in 1989 to a sector field mass spectrometer (funded by the Minister of Science and Technology; again in cooperation with Finnigan MAT). The latter device was launched to the market in 1993 as the Element 1.
The second decade of my career was still related to instrumental development but mainly of glow discharge sources. In an EU funded project first an automated glow discharge sector field instrument was developed where the Grimm type geometry was combined with a fast flow concept (in cooperation with Volker Hoffmann at IFW in Dresden). This was done in cooperation with VG (which became later a part of Thermo Fisher Scientific together with Finnigan MAT), so that it is not surprising that this concept for the Element GD. This project was later continued in the third phase of my career, again funded by the EU and in cooperation with the group of Alfredo Sanz-Medel (Rosario Pereiro and Jorge Pisonero), to develop a fast flow, but now rf-powered GD ion source in combination with a time-of-flight mass spectrometer, which was later launched to the market commercially by Horiba Jobin Yvon (France) for in-depth profiling of thin layers even of non-conducting materials.
In the first decade of my career I started to study already “analytical chemistry” from the scratch because the instruments developed have been applied now for direct analysis of solid materials, technical layers and environmental samples. In case of environmental applications our ICP-MS (the quadrupole and the sector field instrument) was coupled with separation techniques, so that this period of instrumental development was dominated in the second decade by development of high efficiency sample introduction systems in combination with speciation studies of Pt group elements, arsenic, selenium and phosphorus (in DNA and phosphorylated proteins), Ni and Cr. Additionally, we continued with the analysis of solid ceramic materials (Al2O3, SiC, SiN) and ambient air-born particles. At the end of the second decade we complemented our instrumental pool by a collision and reaction cell instrument in cooperation with Micromass and used this instrument for speciation studies of peptides and proteins and demonstrated that by ICP-HEX-MS quantitative proteomics is feasible. Therefore, we more and more focused in the following years on metalloproteins and published a famous paper on “Metallobiomolecules: The basis of life, the challenge of atomic spectroscopy” (together with Luc Moens and Ryszard Lobinski). For detection of metalloproteins we applied typical workflows of biochemistry and proteomics, for which I had to extend my knowledge about biochemistry and proteomics. As a new analytical tool, we used a homemade laser ablation cell for sample introduction of metalloproteins after their separation by gel electrophoresis and extended this work by applying metal-tagging of antibodies for Western blot assays. For this purpose, proteins were separated in SDS-PAGE and electroblotted onto membranes. Specific detection of proteins even not containing any metal could be performed by laser ablation ICP-MS using the metal tagged antibodies for indirect detection. This research was interrupted in 2009 by a movement from ISAS (where atomic spectroscopy was declining) to BAM (the Federal Institute for Materials Research and Testing, Berlin) where this research direction was fostered. The experience we achieved at ISAS in the previously mentioned projects were now used here at BAM in the fourth decade for materials research and the development of a quantitative elemental microscope with cellular resolution. So, at the end of my career I am trying to apply all my knowledge and expertise to develop analytical methods and to apply multimodal spectroscopies to decipher the construction code of the cellular machinery, which is the most precise and complex machinery I have ever seen. If we were able to understand how this machinery works, we can better diagnose and treat a malfunction in case of the development of a disease.
Finally, I can conclude that lifelong learning starts before school but does not end at the end of this lecture. It looks like this heritage lecture will be focused on my career only, but this is not the case because some highlights of my career will be used to illustrate a few universal principles: how to have fun, how to find friends and how this all leads to an increase of joy and joy is the basis of new ideas (which must not always be related to your profession) and novel ideas are essential for a successful and satisfying career. So, this heritage lecture wants to answer the most important question of a life which was dedicated to plasma spectrochemistry:
1) Is it possible - at all - to have fun in this research direction?
2) Can we learn already today what we need tomorrow?
3) How can we still realize our scientific dreams of cutting edge research in times of cutting budgets? Which automatically leads to the next question:
4) Is necessity the mother of invention?
All questions will be answered! Controversial discussions (for angry or disappointed colleagues) will be stimulated and my visions of future research (for students and postdocs) and instrumental developments (for manufacturer) will be presented. Finally, conclusions will be drawn by the auditorium (everybody) and thanks will be given to Ramon Barnes (by me) already in advance!
qNMR provides the most universally applicable form of direct concentration or purity determination without need for reference materials of impurities or the calculation of response factors but only exhibiting suitable NMR properties.
The workshop presents basic terms of statistics and uncertainty analysis, which are the basis for qNMR spectroscopy and data analysis such as, e.g., standard deviations, linear regression, significance tests, etc. and gives typical examples of applications in qNMR spectroscopy.
The departure from the current automation landscape to next generation automation concepts for the process industry has already begun. Smart functions of sensors simplify their use and enable plug-and-play integration, even though they may appear to be more complex at first sight. Monitoring specific information (i.e., “chemical” such as physico-chemical properties, chemical reactions, etc.) is the key to “chemical” process control.
The talk introduces a smart online NMR sensor module provided in an explosion proof housing as example. This sensor was developed for an intensified industrial process (pharmaceutical lithiation reaction step) funded by the EU’s Horizon 2020 research and innovation programme (www.consens-spire.eu). Due to NMR spectroscopy as an “absolute analytical comparison method”, independent of the matrix, it runs with extremely short set-up times in combination with “modular” spectral models. Such models can simply be built upon pure component NMR spectra within a few hours (i.e., assignment of the NMR signals to the components) instead of tedious calibrations runs.
The talk also generally covers current aspects of high-field and low-field online NMR spectroscopy for reaction monitoring and process control and gives also an overview on direct dissolution studies of API cocrystals.
Hydrogen determination in weld seams is standardized in ISO 3690. In accordance to this standard, a defined time for hydrogen collection has to be anticipated for different extraction temperatures. In other words, the temperature is the most important value that has to be monitored in addition to the aimed hydrogen determination.
The specimen geometry has influence on the real sample temperature during CGHE vs. the adjusted furnace temperature. This presentation gives a short summary on possible influences on the "correct" hydrogen determination temperature during carrier gas hot extraction (CGHE) using infrared radiation driven furnace. The main findings are: (1) specimen surface is important in terms of polished or oxidized condition, (2) specimen geometry is important for fast heating, (3) PID-values of control software are a considerable influence to accelerate the heating process depite thick specimens and (4) independent sample temperature determination before CGHE is strongly recommended.
Mykotoxine werden als sekundäre Metabolite von Schimmelpilzen gebildet und haben diverse schädliche Effekte auf Menschen, Tiere und Pflanzen. Laut FAO sind weltweit bis zu 25 % aller Lebens- und Futtermittel mit Mykotoxinen kontaminiert, wodurch jährlich immense ökonomische Verluste entstehen.
Neben den eigentlichen Mykotoxinen rücken zunehmend deren Transformationsprodukte (TPs) in den Fokus. Diese können als natürliche Stoffwechselprodukte toxischer sein als das eigentliche Mykotoxin und stellen eine potenzielle zusätzliche Gefahr für den Verbraucher dar. TPs werden überwiegend mit in vitro und in vivo Techniken untersucht, welche sowohl zeit- als auch kostenintensiv sind. Ziel war es nun, schnelle und zudem verlässliche Techniken zur Simulation von TPs diverser Mykotoxine zu testen. Die Kopplung von Elektrochemie und Massenspektrometrie, kurz EC/MS, als rein instrumenteller Ansatz ist seit vielen Jahren in der pharmazeutischen Forschung etabliert. Hierbei wird mithilfe einer elektrochemischen Durchflusszelle der oxidative Metabolismus einer Substanz simuliert und zugleich analysiert.
Unter Verwendung von EC/MS, EC/LC/MS und HPLC-MS Techniken (MS/MS und FT-ICR) wurden nun die Mykotoxine Zearalenon, Citrinin und Dihydroergocristin (als Modellsubstanz für die Ergotalkaloide) elektrochemisch bei Potentialen bis zu 2500 mV vs. Pd/H2 oxidiert und deren TPs mit mikrosomalen in vitro Ansätzen verglichen. Hierbei konnten mehrere Übereinstimmungen hydroxylierter Spezies, sowohl elektrochemisch als auch biochemisch generiert, festgestellt werden. Die EC/MS ist somit auch in der Lebensmittelanalytik als nützliches und vielseitiges Werkzeug verwendbar.
Quantifizierung der Schädigung von DNA in wässriger Lösung unter direkter Elektronenbestrahlung
(2018)
To cure cancer radiation therapy is used to kill tumor cells.
It is based on radiation induced damage to biomolecules.
Especially DNA damage is of key interest due to its central role in apoptosis and mutation.
Because of the high amount of water in biological tissue, most of the damage is caused by the secondary particles produced by the inelastic scattering of ionizing radiation and water.
A detailed understanding of the underlying molecular processes under physiological conditions is the prerequisite to develop more efficient therapies.
Goal of this work is to quantify the DNA damage caused by ionizing radiation in dependence of the inelastic scattering events and the energy deposit within the microscopic target volume of biological relevance.
The irradiations have to be performed in liquid, under consideration of the chemical environment.
Therefore, a new combination of experiment and Monte-Carlo simulations was developed and tested.
To make it possible to irradiate liquids with electrons within scanning electron microscopes a new sample holder was constructed incorporating an electron transparent nanomembrane.
It makes it possible to irradiate DNA, proteins or cells at different pH, salinity and in the presence of cosolutes.
%The most important results of this work are as follows:
The median lethal dose for a model system of plasmid DNA and water was determined by the combination of experimental data, particle scattering simulations (Geant4-DNA) and diffusion calculations as D0.5=(1.7+-0.3) Gy.
From the convolution of plasmid positions and the spatially resolved energy deposit, as determined by electron scattering simulations, the histogram of the energy deposit within the target volume of the plasmids and the microscopic median lethal energy deposit was calculated as E0.5=6+-4eV.
It could be deduced that on average less than two ionization events are sufficient to cause a single-strand-break.
The relation of single-strand-breaks (SSB) to double-strand-breaks (DSB), which is of importance for microdosimetric modeling, was determined as SSB:DSB = 12:1.
The presented method for the determination of microscopic dose-damage relations was further extended to be applicable for general irradiation experiments.
It becomes independent of the type of primary radiation used, the experimental geometry, and the diffusional properties of the molecules under investigation.
This way different experimental systems with varying, inhomogeneous energy deposit characteristics become comparable with each other, which is not possible when only macroscopic averaged values are taken into account.
In addition, the radiation protection properties of the compatible solute ectoine, as well as its influence on the water properties and biomolecules were investigated.
%In addition, the influence of the compatible solute ectoine on water, biomolecules and its radiation protection properties were investigated.
Raman spectroscopy revealed a concentration dependent increase of the collective water modes in the OH-stretching region, which was found to be independent of the sodium chloride concentration.
Molecular dynamic simulations showed that the zwitterionic properties of ectoine lead to its half-chair conformation.
The hydrogen bonds in the first hydration shell are more stable and have an increased lifetime compared to the bulk water.
Irradiation experiments with DNA in the presence of 1M ectoine revealed an increase of the survival rate by a factor of 1.41 as compared to the absence of ectoine.
The protective properties of ectoine result from the increase of the inelastic scattering probabilities of low energy electrons at the acoustic vibrational modes of water and its properties as OH-radical scavenger.
This was shown by Raman spectroscopy and electron paramagnetic resonance measurements (EPR).
The overall interest in nanotoxicity, triggered by the increasing use of nanomaterials in the material and life sciences, and the synthesis of an ever increasing number of new functional nanoparticles calls for standardized test procedures1,2 and for efficient approaches to screen the potential genotoxicity of these materials. Aiming at the development of fast and easy to use, automated microscopic methods for the determination of the genotoxicity of different types of nanoparticles, we assess the potential of the fluorometric γH2AX assay for this purpose. This assay, which can be run on an automated microscopic detection system, relies on the detection of DNA double strand breaks as a sign for genotoxicity3. Here, we provide first results obtained with broadly used nanomaterials like CdSe/CdS and InP/ZnS quantum dots as well as iron oxide, gold, and polymer particles of different surface chemistry with previously tested colloidal stability and different cell lines like Hep-2 and 8E11 cells, which reveal a dependence of the genotoxicity on the chemical composition as well as the surface chemistry of these nanomaterials. These studies will be also used to establish nanomaterials as positive and negative genotoxicity controls or standards for assay performance validation for users of this fluorometric genotoxicity assay. In the future, after proper validation, this microscopic platform technology will be expanded to other typical toxicity assays.