TY - JOUR A1 - Riedel, Soraya A1 - Hülagü, Deniz A1 - Bennet, Francesca A1 - Carl, Peter A1 - Flemig, Sabine A1 - Schmid, Thomas A1 - Schenk, J. A. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf T1 - Electrochemical Immunomagnetic Ochratoxin A Sensing: Steps Forward in the Application of 3,3’,5,5’- Tetramethylbenzidine in Amperometric Assays N2 - Electrochemical methods offer great promise in meeting the demand for user-friendly on-site devices for Monitoring important parameters. The food industry often runs own lab procedures, for example, for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with smart technologies. Enzyme-linked immunosorbent assays, with photometric detection of 3,3’,5,5’-tetramethylbenzidine (TMB),form a good basis for sensitive detection. To provide a straightforward approach for the miniaturization of the detectionstep, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry it was found that the TMB electrochemistry is strongly dependent on the pH and the electrode material. A stable electrode response to TMB could be achieved at pH 1 on gold electrodes. We created a smartphonebased, electrochemical, immunomagnetic assay for the detection of ochratoxin A in real samples, providing a solid basis forsensing of further analytes. KW - Ochratoxin A KW - Amperometry KW - Cyclic voltammetry KW - Electrochemistry KW - Immunoassay PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530421 DO - https://doi.org/10.1002/celc.202100446 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. VL - 8 IS - 13 SP - 2597 EP - 2606 AN - OPUS4-53042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Stephan A1 - Hoffmann, Holger A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Liquid chromatography-tandem mass spectrometry detection of diclofenac and related compounds in water samples N2 - A frequently studied environmental contaminant is the active substance diclofenac, which is removed insufficiently in sewage treatment plants. Since its inclusion in the watch list of the EU Water Framework Directive, the concentrations in surface waters will be determined throughout Europe. For this, still, more precise analytical methods are needed. As a reference, HPLC-MS is frequently employed. One of the major metabolites is 4’-hydroxydiclofenac (4’-OH-DCF). Also, diclofenac lactam is important for assessing degradation and transformation. Aceclofenac (ACF), the glycolic acid ester of diclofenac is used as a drug, too, and could potentially be cleaved to yield diclofenac again. In various sewage treatment plant influent samples, diclofenac, 4’-OH-DCF, DCF lactam and ACF could be determined with detection limits of 3 µg/L, 0.2 µg/L, 0.17 µg/L and 10 ng/L, respectively. KW - Diclofenac KW - Festphasenextraktion KW - HPLC-MS KW - Probenvorbereitung KW - Kläranlage KW - Abwasser KW - Zyklisierung KW - Diclofenac KW - Solid-phase extraction KW - Sewage treatment plant KW - Cyclization KW - Sample treatment KW - HPLC–MS PY - 2018 DO - https://doi.org/10.1016/j.chroma.2018.01.037 SN - 0021-9673 SN - 1873-3778 VL - 1538 SP - 112 EP - 116 PB - Elsevier B.V. CY - Amsterdam, NL AN - OPUS4-44183 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riedel, Soraya A1 - Hülagü, Deniz A1 - Bennet, Francesca A1 - Carl, Peter A1 - Flemig, Sabine A1 - Schmid, Thomas A1 - Schenk, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf T1 - Steps Forward in the Application of 3,3’,5,5’- Tetramethylbenzidine (TMB) in Amperometric Assays N2 - Electrochemical methods make great promise to meet the demand for user-friendly on-site devices for monitoring important parameters. Food industry often runs own lab procedures, e.g. for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with miniaturized technologies. Enzyme-linked immunosorbent assays, with photometric detection of the horseradish peroxidase (HRP) substrate, 3,3’,5,5’-tetramethylbenzidine (TMB), form a good basis for sensitive detection. To provide a straight-forward approach for the miniaturization of the detection step, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry it was found that the TMB electrochemistry is strongly dependent on the pH and the electrode material. It was found that screen-printed gold electrodes and a highly acidic pH value (pH 1) are well-suited to perform the electrochemical detection of TMB, due to the reversible character of the redox reaction under these conditions. This set-up provides a good signal stability over several measuring cycles, providing the basis for analysing multiple samples. In contrast to this, for carbon screen-printed electrodes, it was found that the signal response has changed after the electrochemical reaction with TMB at pH 1. At a weakly acidic pH value (pH 4), neither with carbon nor with gold electrodes a reproducible electrochemical detection of TMB could be achieved [1]. Based on these findings we created a smartphone-based, electrochemical, immunomagnetic assay for the detection of ochratoxin A and ergometrine in real samples. Therefore, a competitive assay was performed on magnetic beads using HRP and TMB/H2O2 to generate the signal. Enzymatically oxidized TMB was quantified after addition of H2SO4 by amperometry with screen-printed gold electrodes in a custom-made wall-jet flow cell. The results are in good correlation with the established photometric detection method, providing a solid basis for sensing of further analytes in HRP-based assays using the newly developed miniaturized smartphone-based, electrochemical, immunomagnetic assay. T2 - Electrochemistry 2022 CY - Berlin, Germany DA - 28.09.2022 KW - Cylic Voltammetry KW - Immunoassay KW - TMB KW - Amperometry PY - 2022 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. AN - OPUS4-55876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Stephan A1 - Hoffmann, Holger A1 - Garbe, Leif-Alexander A1 - Harrer, Andrea A1 - Steiner, Markus A1 - Himly, Martin A1 - Schneider, Rudolf T1 - Re-assessment of monoclonal antibodies against diclofenac for their application in the analysis of environmental waters N2 - The non-steroidal anti-inflammatory drug (NSAID) diclofenac (DCF) is an important environmental contaminant occurring in surface waters all over the world, because, after excretion, it is not adequately removed from wastewater in sewage treatment plants. To be able to monitor this pollutant, highly efficient analytical methods are needed, including immunoassays. In a medical research project, monoclonal antibodies against diclofenac and its metabolites had been produced. Based on this monoclonal anti-DCF antibody, a new indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed and applied for environmental samples. The introduction of a spacer between diclofenac and the carrier protein in the coating conjugate led to higher sensitivity. With a test midpoint of 3 mg L−1 and a measurement range of 1–30 mg L−1, the system is not sensitive enough for direct analysis of surface water. However, this assay is quite robust against matrix influences and can be used for wastewater. Without adjustment of the calibration, organic solvents up to 5%, natural organic matter (NOM) up to 10 mg L−1, humic acids up to 2.5 mg L−1, and salt concentrations up to 6 g L−1 NaCl and 75 mg L−1 CaCl2 are tolerated. The antibody is also stable in a pH range from 3 to 12. Cross-reactivity (CR) of 1% or less was determined for the metabolites 40-hydroxydiclofenac (40-OH-DCF), 5-hydroxydiclofenac (5-OH-DCF), DCF lactam, and other NSAIDs. Relevant cross-reactivity occurred only with an amide derivative of DCF, 6-aminohexanoic acid (DCF-Ahx), aceclofenac (ACF) and DCF methyl ester (DCF-Me) with 150%, 61% and 44%, respectively. These substances, however, have not been found in samples. Only DCF-acyl glucuronide with a cross-reactivity of 57% is of some relevance. For the first time, photodegradation products were tested for cross-reactivity. With the ELISA based on this antibody, water samples were analysed. In sewage treatment plant effluents, concentrations in the range of 1.9–5.2 mg L−1 were determined directly, with recoveries compared to HPLC-MS/MS averaging 136%. Concentrations in lakes ranged from 3 to 4.4 ng L−1 and were, after pre-concentration, determined with an average recovery of 100% KW - Antikörper KW - Immunoassay KW - Wasser PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602280 DO - https://doi.org/10.1039/d3ay01333b VL - 16 IS - 21 SP - 3349 EP - 3363 PB - Royal Society of Chemistry (RSC) CY - London AN - OPUS4-60228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Holger A1 - Knizia, Christian A1 - Kuhne, Maren A1 - Panne, Ulrich A1 - Schneider, Rudolf T1 - LC–ELISA as a contribution to the assessment of matrix effects with environmental water samples in an immunoassay for estrone (E1) N2 - Estrone (E1), a metabolite of the estrogenic hormones 17β-estradiol (β-E2) and 17α-estradiol (α-E2), is itself a potent estrogen which can have a significant impact on the hormonal balance. Due to ist high potential for adverse effects on human health and aquatic life even at pg/L to ng/L levels, its appearance in water should be monitored. E1 has also been considered a marker substance for the presence of other estrogens. This study presents a newly developed direct competitive enzymelinked immunosorbent assay (ELISA) for quantification of E1 in environmental water samples using new monoclonal antibodies. The quantification range of the ELISA is 0.15 μg/L to 8.7 μg/L E1, and the limit of detection is around 60 ng/L for not pre-concentrated water samples. A pre-concentration step after careful selection of suitable phases for SPE was developed, too. The influence of organic solvents and natural organic matter on the ELISA was assessed. The high selectivity of the monoclonal antibody was demonstrated by determining the cross-reactivity against 20 structurally related compounds. For the assessment of matrix effects, a concept (“LC–ELISA”) is thoroughly exploited, i.e., separating complex samples by HPLC into 0.3 min fractions and determination of the apparent E1 concentration. Furthermore, fractions with interferences for nontarget/suspected-target analysis can be assigned. A dilution approach was applied to distinguish between specific interferences (cross-reactants) and non-specific interferences (matrix effects). In the determination of 18 environmental samples, a good agreement of the E1 concentration in the respective fractions was obtained with mean recoveries of 103 % to 132 % comparing ELISA to LC–MS/MS. KW - Validierung KW - Immunoassay KW - Matrixeffekte KW - Abwasser KW - Oberflächenwasser KW - ELISA KW - LC-MS/MS KW - Hormone KW - Endokrine Disruptoren PY - 2018 DO - https://doi.org/10.1007/s00769-018-1351-7 SN - 1432-0517 SN - 0949-1775 VL - 23 IS - 6 SP - 349 EP - 364 PB - Springer CY - Heidelberg AN - OPUS4-46891 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bierstedt, Andreas A1 - Panne, Ulrich A1 - Riedel, Jens T1 - Confinement and enhancement of an airborne atmospheric laser-induced plasma using an ultrasonic acoustic resonator N2 - Optical elemental analysis in the gas phase typically relies on electrically driven plasmas. As an alternative approach, laser-induced plasmas (LIPs) have been suggested but have so far been only scarcely used. Here, a novel signal enhancement strategy for laser-based airborne plasma optical Emission spectroscopy for gas phase analytics is presented. In contrast to an electrically driven plasma, in the laser-induced analogue dynamic matter transport equilibrium builds up. The latter results in a rarefied density regime in the plasma core itself, surrounded by an area of compressed matter. The central rarefaction leads to a decrease in plasma intensity and analyte number density, both of which are detrimental for analytical purposes. Since the repetitive ignition of LIPs is a transient process, a restoration of the former gaseous medium by other dynamically equilibrated diffusion processes would be favourable. The presented combination of an airborne LIP and an ultrasonic acoustic resonator yields a fourfold signal enhancement while the Background contribution of ubiquitous air is at the same time effectively suppressed. Since the entire enhancement effect occurs without contact, no additional sources for abrasive sample contamination are introduced. KW - DPSS laser KW - Laser-induced plasma KW - High repetition rate KW - Ultrasonic acoustic resonator KW - Optical emission spectroscopy PY - 2018 DO - https://doi.org/10.1039/C7JA00297A SN - 0267-9477 SN - 1364-5544 VL - 33 IS - 1 SP - 135 EP - 140 PB - Royal Society of Chemistry CY - London AN - OPUS4-43619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Morcillo, Dalia A1 - Winckelmann, Alexander A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Jacobsen, Lars A1 - Frick, Daniel A1 - Schmidt, Anita A1 - Leonhardt, Robert A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - High-resolution absorption isotopic spectrometry as a tool for aging studies of Li-ion batteries N2 - Lithium (Li) is the key element in the manufacturing of batteries. Isotopic study of Li may help to identify the causes of battery aging due to isotopic fractionation during charge/discharge cycles. Isotopic ratio determination is based on monitoring the isotopic components of lithium by their spin-orbit coupling and its isotopic shift of about 15 pm for the 22P←22S electronic transition around 670.788 nm. In this work, we propose improvements to our previous work [1] by using a higher-resolution double echelle modular spectrometer (HR-DEMON II) coupled to a continuum source graphite furnace atomic absorption spectrometer (HR-CS-GF-AAS) for the isotopic analysis of Li. The data analysis was carried out by using a decision-tree-based ensemble machine learning (ML) algorithm (XGBoost). A set of samples with 6Li isotope amount fractions ranging from 0.0004 to 0.99 mol mol-1 was used for the algorithm's training. Subsequently, the procedure was validated by a set of stock chemicals (Li2CO3, LiNO3, LiCl, and LiOH) and a BAM candidate reference material, a cathode material (NMC111). Finally, the ML model was applied to determine the isotope ratio of geological samples, including anorthosite, granite, soil, rhyolite, nepheline syenite, and basalt and battery samples. These samples were measured as digested without any further purification step. Improvements in the optical resolution resolve the lithium isotopic components of the atomic spectra. In the studied geological samples, were found δ7Li values between -0.5 and 4.5 ‰ with a precision range of 1 to 2 ‰. In addition, the proposed method was validated with multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), and these results are comparable and compatible. T2 - Caltech-BAM Meeting CY - Online meeting DA - 10.08.2022 KW - Lithium isotope KW - Machine learning KW - Battery KW - High-resolution absorption isotopic spectrometry PY - 2022 AN - OPUS4-56380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Weigert, Florian A1 - Häusler, I. A1 - Geißler, Daniel A1 - Resch-Genger, Ute T1 - Correlating HR-TEM and XPS to elucidate the core-shell structure of ultrabright CdSE/CdS semiconductor quantum dots N2 - Controlling the thickness and tightness of surface passivation shells is crucial for many applications of core-shell nanoparticles (NP). Usually, to determine shell thickness, core and core/shell particle are measured individually requiring the availability of both nanoobjects. This is often not fulfilled for functional nanomaterials such as many photoluminescent semiconductor quantum dots (QD) used for bioimaging, solid state lighting, and display technologies as the core does not show the application-relevant functionality like a high photoluminescence (PL) quantum yield. This calls for a whole nanoobject approach. Moreover, the thickness of the organic coating remains often unclear. By combining high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS), a novel whole nanoobject approach is developed representatively for an ultrabright oleic acid-stabilized, thick shell CdSe/CdS QD with a PL quantum yield close to unity. The size of this spectroscopically assessed QD, is in the range of the information depth of usual laboratory XPS. Information on particle size and monodispersity were validated with dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) and compared to data derived from optical measurements. The results of the different methods match very well within the different measurement uncertainties. Additionally, results obtained with energy-resolved XPS using excitation energies between 200 eV and 800 eV are discussed with respect to a potential core/shell intermixing. Moreover, the future application potential of this approach correlating different sizing and structural methods is discussed considering the method-inherent uncertainties and other core/multi-shell nanostructures. T2 - E-MRS Fall Meeting CY - Online meeting DA - 20.09.2021 KW - Core-shell nanoparticles KW - Quantum dots KW - High-resolution transmission electron microscopy KW - X-ray Photoelectron Spectroscopy PY - 2021 AN - OPUS4-53365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Morcillo, Dalia A1 - Abad Andrade, Carlos Enrique A1 - Winckelmann, Alexander A1 - Frick, D. A1 - Jacobsen, L. A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Vogl, Jochen A1 - Panne, Ulrich T1 - Atomic absorption spectroscopy and machine learning for lithium isotopic study N2 - The isotopic analysis of lithium is also relevant to the study of geological phenomena.1 In this work we propose improvements to the method for the isotopic analysis of lithium using a high-resolution continuum source atomic absorption spectrometer (HR-CS-AAS) coupled to a double echelle modular spectrometer (DEMON). 2 This tool for isotopic ratio determination is based on monitoring the isotopic components of lithium by their spin-orbit coupling and its isotopic shift of about 15 pm for the 22P←2 2S electronic transition around 670.788 nm. The data analysis was carried out by using a decision-tree-based ensemble machine learning (ML) algorithm. For the training of the algorithm (XGBoost), a set of samples with 6Li isotope amount fractions ranging from 0.06 to 0.99 mol-1 was used. Subsequently, the procedure was validated of a set of stock chemicals (Li2CO3, LiNO3, LiCl and LiOH) and a BAM candidate reference material, the cathode material LiNi1/3Mn1/3Co1/3O2 (NMC111). Finally, the ML model was applied to the set of geological samples, previously digested, for the determination of their isotope ratio. The optical resolution was improved from 140,000 to 790,000 to better deconvolution the lithium isotopic components in the atomic spectrum. And the method was compared with multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The results are metrologically comparable. T2 - Colloquium Spectroscopicum Internationale XLII (CSI XLII) CY - Gijón, Spain DA - 30.05.2022 KW - Lithium isotope KW - Atomic absorption spectroscopy PY - 2022 AN - OPUS4-56357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - Muench, S. A1 - Okruss, M. A1 - Mao, X. A1 - Gonzalez, J. A1 - Zorba, V. A1 - Recknagel, Sebastian A1 - Tatzel, Michael A1 - Vogl, Jochen A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Critical evaluation of optical spectrometry vs mass spectrometry for stable isotope analysis N2 - 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. Optical spectrometric methods are proposed as faster and low-cost alternative for the analysis of isotope ratios of selected elements by means of high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS) and laser ablation molecular isotopic spectrometry (LAMIS). First, stable isotope amount compositions of boron (B) and magnesium (Mg) were determined based on the absorption spectra of in-situ generated heteronuclear diatomic molecules (MH or MX) in 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. Finally, the application of molecular spectrometry via emission by LAMIS is compared and discussed. T2 - European Winter Conference on Plasma Spectrochemistry EWCPS 2019 CY - Pau, France DA - 03.02.2019 KW - Isotope analysis KW - HR-CS-MAS KW - LIBS KW - MS-ICP-MS KW - Optical spectroscopy KW - Mass spectrometry PY - 2019 AN - OPUS4-49874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Krietsch, Arne A1 - Rühle, Bastian A1 - Bresch, Harald T1 - Perspective of BAM on Advanced Materials N2 - A brief perspective of BAM on advanced materials is presented including examples for nanomaterials and other systems presenting advanced materials with special emphasis on characterization methods used in different division of BAM for the determination of functional or safety parameters of such materials. In this respect, also ongoing activities of the capacity building project nanoplatform of BAM aiming at the development of nanometer-sized reference materials are briefly summarized. T2 - BfR Workshop zu Advanced Materials CY - Online meeting DA - 04.11.2020 KW - Quality assurance KW - Risk assessment KW - Safety KW - Core/shell particle KW - Characterization KW - Measurement uncertainty KW - Method KW - Nano particle PY - 2020 AN - OPUS4-51620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tuma, Dirk A1 - Kipphardt, Heinrich A1 - Khanipour, P. T1 - Preparation and Analysis of Trace Compounds in Hydrogen in the ppm and Sub-ppm Region Relevant for Applications N2 - ISO 14687 defines threshold limits for expectable impurities in hydrogen that is assigned for use in polymer electrolyte membrane (PEM) fuel cells. This work describes the establishment of the traceability of some selected impurities by preparation and analysis of reference gases with the lowest possible uncertainty in composition. Primary reference gases were produced by the gravimetric method according to ISO 6142-1 and the analysis was carried out by operating measurement protocols according to ISO 12963 on two customized trace GC analysers. T2 - ANAKON 2023 CY - Vienna, Austria DA - 11.04.2023 KW - Hydrogen analysis KW - Gravimetric preparation KW - Gas chromatography PY - 2023 AN - OPUS4-57329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jakubowski, Norbert A1 - Müller, L. A1 - Traub, Heike A1 - Esteban-Fernández, D. A1 - Panne, Ulrich A1 - Wanka, Antje A1 - Kneipp, J. T1 - Method development for metal detection at cellular levels by ICP-MS N2 - 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. T2 - Projektmeeting CY - Bremen, Germany DA - 18.04.2018 KW - Single cell ICP-MS KW - LA-ICP-MS with cellular resolution KW - Nanoparticles PY - 2018 AN - OPUS4-44851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jakubowski, Norbert A1 - Müller, L. A1 - Traub, Heike A1 - Esteban-Fernández, D. A1 - Panne, Ulrich A1 - Wanka, Antje A1 - Schellenberger, E. A1 - Theuring, F. A1 - Kneipp, J. T1 - Method development for metal detection at cellular levels by ICP-MS N2 - 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. T2 - ACS Annual Meeting CY - New Orleans, LA, USA DA - 18.03.2018 KW - Single cell ICP-MS KW - LA-ICP-MS with cellular resolution KW - Nanoparticles PY - 2018 AN - OPUS4-44799 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jakubowski, Norbert A1 - Müller, L. A1 - Traub, Heike A1 - Esteban-Fernández, D. A1 - Panne, Ulrich A1 - Wanka, Antje A1 - Kneipp, J. T1 - Method development for metal detection at cellular levels by ICP-MS N2 - 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. T2 - 16th Czech-Slovak Spectroscopic Conference CY - Luhacovice, Czech Republic DA - 27.05.2018 KW - Single cell analysis KW - ICP-MS KW - Nanoparticles PY - 2018 AN - OPUS4-45161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - Recknagel, Sebastian A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Following fluorinated drugs by molecular absorption spectrometry – from cancer cells to body fluids N2 - 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. T2 - 16th Annual Congress of International Drug Discovery Science and Technology 2018 CY - Cambridge, MA, USA DA - 16.08.2018 KW - Fluorine KW - Anti-cancer KW - Capecitabine KW - Fluorouracil KW - HR-CS-MAS PY - 2018 AN - OPUS4-45822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland T1 - Non-invasive cancer detection using volatile biomarkers: Is urine superior to breath? N2 - In recent years numerous reports have highlighted the options of chemical breath analysis with regard to noninvasive cancer detection. Certain volatile organic compounds (VOC) supposedly present in higher amounts or in characteristic patterns have been suggested as potential biomarkers. However, so far no clinical application based on a specific set of compounds appears to exist. Numerous reports on the capability of sniffer dogs and sensor arrays or electronic noses to distinguish breath of cancer patients and healthy controls supports the concept of genuine cancer-related volatile profiles. However, the actual compounds responsible for the scent are completely unknown and there is no correlation with the potential biomarkers suggested on basis of chemical trace analysis. It is outlined that specific features connected with the VOC analysis in breath – namely small concentrations of volatiles, interfering background concentrations, considerable sampling effort and sample instability, impracticability regarding routine application - stand in the way of substantial progress. The underlying chemicalanalytical challenge can only be met considering the severe susceptibility of VOC determination to these adverse conditions. Therefore, the attention is drawn to the needs for appropriate quality assurance/quality control as the most important feature for the reliable quantification of volatiles present in trace concentration. Consequently, the advantages of urine as an alternative matrix for volatile biomarker search in the context of diagnosing lung and other cancers are outlined with specific focus on quality assurance and practicability in clinical chemistry. The headspace over urine samples as the VOC source allows adapting gas chromatographical procedures well-established in water analysis. Foremost, the selection of urine over breath as non-invasive matrix should provide considerably more resilience to adverse effects during sampling and analysis. The most important advantage of urine over breath is seen in the option to partition, dispense, mix, spike, store, and thus to dispatch taylor-made urine samples on demand for quality control measures. Although it is still open at this point if cancer diagnosis supported by non-invasively sampled VOC profiles will ultimately reach clinical application the advantages of urine over breath should significantly facilitate urgently required steps beyond the current proof-of-concept stage and towards standardisation. KW - VOC KW - Breath KW - Urine KW - Lung cancer KW - Volatile organic compounds PY - 2020 DO - https://doi.org/10.1016/j.mehy.2020.110060 VL - 143 SP - 110060 PB - Elsevier Ltd. AN - OPUS4-51066 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Junge, Florian A1 - Wittwer, Philipp A1 - Sommerfeld, Thomas A1 - Gehrenkemper, Lennart A1 - Zoister, Christian A1 - Nickl, Philip A1 - Koch, Matthias A1 - Meermann, Björn A1 - Haag, Rainer T1 - Adsorber Charge Dominates over Hydrophobic or Fluorophilic Functionalization in Influencing Adsorption of PFCA onto Polystyrene Resins N2 - A systematic series of industrial-relevant polystyrene-based anion exchange resins that are functionalized with hydro- or fluorocarbon chains are compared regarding their adsorption behavior toward perfluorocarboxylic acids (PFCA) in respect to their charge, chain length, and type of chain. The results clearly show the dominance of electrostatic interactions in the adsorption process as uncharged adsorber materials showed no adsorption at all. In contrast, the charged adsorber materials showed in general a PFCA removal of 80% to 30% over the experiment depending on effluent fraction. Unexpectedly, for perfluorobutanoic acid (PFBA) the highest removal rate is found with consistently >90%. Despite observing significant benefits in the adsorption of PFCA for fluoroalkylated adsorbers in comparison to their non-fluorinated counterparts, this effect of fluoroalkylation is comparatively small and can not be clearly attributed to fluorophilic interactions between the fluoroalkyl chains. These findings help clarifying that the introduction of fluorocarbon moieties in adsorber materials is not necessary in order to remove fluorocarbon molecules from the environment. KW - PFAS KW - Remediation KW - Adsorption KW - Fluorophilic interactions PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601883 DO - https://doi.org/10.1002/admi.202400199 SN - 2196-7350 SP - 1 EP - 10 PB - John Wiley & Sons CY - Hoboken, New Jersey, USA AN - OPUS4-60188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radnik, Jörg A1 - Knigge, Xenia A1 - Andresen, Elina A1 - Resch-Genger, Ute A1 - Cant, D.J.H. A1 - Shard, A.G. A1 - Clifford, C.A. T1 - Composition, thickness, and homogeneity of the coating of core–shell nanoparticles—possibilities, limits, and challenges of X-ray photoelectron spectroscopy N2 - Core–shell nanoparticles have attracted much attention in recent years due to their unique properties and their increasing importance in many technological and consumer products. However, the chemistry of nanoparticles is still rarely investigated in comparison to their size and morphology. In this review, the possibilities, limits, and challenges of X-ray photoelectron spectroscopy (XPS) for obtaining more insights into the composition, thickness, and homogeneity of nanoparticle coatings are discussed with four examples: CdSe/CdS quantum dots with a thick coating and a small core; NaYF4-based upconverting nanoparticles with a large Yb-doped core and a thin Er-doped coating; and two types of polymer nanoparticles with a poly(tetrafluoroethylene) core with either a poly(methyl methacrylate) or polystyrene coating. Different approaches for calculating the thickness of the coating are presented, like a simple numerical modelling or a more complex simulation of the photoelectron peaks. Additionally, modelling of the XPS background for the investigation of coating is discussed. Furthermore, the new possibilities to measure with varying excitation energies or with hard-energy X-ray sources (hard-energy X-ray photoelectron spectroscopy) are described. A discussion about the sources of uncertainty for the determination of the thickness of the coating completes this review. KW - X-ray spectroscopy KW - Nanoparticles KW - Spectroscopy / Instrumentation KW - Spectroscopy / Theory PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548305 DO - https://doi.org/10.1007/s00216-022-04057-9 VL - 414 IS - 15 SP - 4331 EP - 4345 PB - SpringerNature AN - OPUS4-54830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Löhr, Konrad A1 - Traub, Heike A1 - Wanka, Antje Jutta A1 - Panne, Ulrich A1 - Jakubowski, Norbert T1 - Quantification of metals in single cells by LA-ICP-MS: Comparison of single spot analysis and imaging N2 - LA-ICP-MS is increasingly used for single cell analysis in two different detection modes using either the imaging mode with subcellular resolution or alternatively single spot analysis of cells with a larger laser spot size. This study compares the analytical figures of merit of both detection modes (signal to noise, precision, accuracy, throughput), as well as ease of operation and data evaluation. Adherent 3T3 fibroblast cells were stained with two metal dyes (mDOTA-Ho, Ir-DNA-intercalator) and several dozen cells were measured using both modes. We found a ten times higher throughput for single spot analysis, which has as well a straightforward data analysis, shortening the total analysis time further. The signal to noise ratio for single spot analysis was found to be slightly better compared to the signal to noise of pixels in imaging. The mean metal intensity per single cell differed by only 10% between both modes and obtained distributions were found to show no statistically significant differences. Using matrix matched calibration based on standards spotted onto nitrocellulose membrane, we achieved detection limits (10s) of 12 fg for Ir and 30 fg for Ho and quantified 57 +/-35 fg Ir and 1192 +/- 707 fg Ho per single cell. Compared to a conventional ICP-MS measurement of a digest of about 60000 cells, 54% of Ir content and 358% Ho content was found using quantitative LA-ICP-MS. The difference might be a consequence of the two metal dyes binding to different structures of the cell and therefore might behave differently in sample preparation for conventional and LA-ICP-MS. KW - Cells KW - Laser ablation KW - ICP-MS KW - Metals KW - Quantification PY - 2018 DO - https://doi.org/10.1039/c8ja00191j SN - 0267-9477 VL - 33 IS - 9 SP - 1579 EP - 1587 PB - RSC Royal Society of Chemistry CY - London AN - OPUS4-46441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -