TY - CONF A1 - Riedel, Soraya T1 - Smartphone-based amperometric detection of 3,3′,5,5′-tetramethylbenzidine (TMB) – An immunomagnetic Ochratoxin A assay N2 - The demand for miniaturized analytical devices monitoring important parameters in the food and medical industry has increased strongly in the past decades. With fast progress, smart technologies are finding their way into our everyday life. For the future, it is, therefore, a major goal to also link analytical methods with smart technologies to create user-friendly on-site devices. In food industry the monitoring of harmful substances such as dioxins, heavy metals or mycotoxins plays a key role, since the European Commission prescribes legal limits for various food products and beverages[1]. Therefore, companies often have their own laboratories and trained personnel. For one of the most abundant and toxic mycotoxins, Ochratoxin A (OTA) we want to present an electrochemical detection system in which the read-out can be performed with a smartphone connected via Bluetooth to a miniaturized potentiostat. The recognition of OTA is performed with specific antibodies in a competitive assay format. Anti-OTA-antibodies were captured on magnetic beads on which the competitive binding between OTA and an OTA horseradish peroxidase (HRP) tracer was performed. To quantify OTA, the enzymatic reaction of the tracer with 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2 is employed. Oxidized TMB, which is enzymatically produced by the reduction of H2O2, is quantified by amperometry with screen-printed electrodes in a custom-made flow system. Since it is well-known that oxidized TMB can precipitate on electrode surfaces[2], we have studied pitfalls of the electrochemical detection of TMB. By cyclic voltammetry we have compared the stability of the electrochemistry of TMB at different electrode materials (gold and carbon) and pH values (pH 1 and pH 4). It was found that a stable response of the electrode could be achieved at pH 1 on gold electrodes. Thus, we applied these reaction conditions for amperometric detection of TMB in the OTA assay. The results of the electrochemical detection method are in good correlation with the photometric detection of TMB. To demonstrate the applicability, we tested our system with OTA-spiked beer and performed the measurement via smartphone. T2 - European Biosensor Symposium 2021 CY - Online meeting DA - 09.03.2021 KW - Ochratoxin A KW - Cyclic voltammetry KW - Amperometry KW - Smartphone KW - Immunoassay PY - 2021 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. AN - OPUS4-52269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ecke, Alexander T1 - The Fate of the Antibiotic Amoxicillin in the Aquatic Environment N2 - Contamination of the environment with antibiotics is of great concern as it promotes the evolution of antimicrobial resistances. In case of amoxicillin (AMX) in the aquatic environment, further risk arises from hydrolysis products (HPs) which can cause allergy. To assess these risks, a comprehensive investigation and understanding of the degradation of AMX is necessary. We investigated the hydrolysis rate of AMX in different types of water as well as the influence of temperature and irradiation. The content of the heavy metal ions copper and zinc was found to be crucial for the hydrolysis rate of AMX and stability of HPs. Eventually, a new degradation pathway for AMX could be elaborated and confirmed by tandem mass spectrometry (LC-MS/MS). T2 - Berliner Chemie in Praxis Symposium CY - Berlin, Germany DA - 07.10.2022 KW - Hydrolysis KW - Amoxicillin KW - LC-MS/MS KW - ICP-MS PY - 2022 AN - OPUS4-56026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frenzel, Olivia T1 - Identification of Metabolites and Transformation Products of Bisphenols N2 - Bisphenol A (BPA) is used in Polycarbonate, Polyacrylic resins, Polysulfones, Epoxy resins, and Polyetherimides. It is also used in recycled Polyvinyl chloride [1–3]. BPA has been classified as a substance of very high concern (SVHC) under REACH [4] due to its endocrine disrupting properties. The German competent authorities want to reduce the content of BPA in the environment. Possible substitutes for BPA are Bisphenol B (BPB), Bisphenol E (BPE), Bisphenol F (BPF), or Bisphenol S (BPS), as they are similar in structure. BPA-based materials have a wide area of application especially outside. These outdoor applications are exposed to different external influences, including physical, biological, mechanical and chemical influences. This results in damage and aging of the material with leaching or migration into the environment. There, the substance is transformed by various transformation processes. The emerging metabolites and transformation products (TPs) can have different properties than the parent substance. Understanding the fate and behavior of the emerging pollutants is very important. Therefore, different transformation products of selected bisphenols will be generated and analyzed: To investigate the fate of different bisphenols in water treatment plants technical transformation products [5] will be generated by chlorination, ozonization, the Fenton reaction, and UV-radiation. For the investigation of the fate of Bisphenols in surface water global radiation will be simulated with UVA-lamps Simulation of phase-I-metabolism with an electrochemical cell coupled to mass spectrometry (EC-MS). T2 - Anakon 2023 CY - Vienna, Austria DA - 11.04.2023 KW - Transformation products KW - Bisphenols KW - Metabolites KW - Wastewater KW - Environment PY - 2022 AN - OPUS4-57374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hantschke, Luisa Lamberta T1 - Comparison of three different TOP-Assay approaches for the determination of PFAS concentration in soil N2 - Per- and polyfluoroalkyl substances (PFAS) are a large, ever-growing and widely used class of chemicals. Due to the strength of the C-F bond, they do not decompose but accumulate in the environment posing a risk for nature and humans alike. While the use of some PFAS, like perfluorooctanoic acid (PFOA) is already regulated in the EU, new ‘precursor’ substances are used to replace them. However, these precursors may be equally harmful to the environment. In recent years, many ‘hot spot’ sites with high PFAS contaminations in soil have been distinguished, but no German-wide background values have been determined yet. Knowing these background values is crucial to understand the degree of PFAS contamination, underpinning future regulatory decisions. Due to the complexity and variety of different PFAS compounds, one needs to apply a broad spectrum of different techniques to capture most of the PFAS content in one sample. In the framework of this project, 600 soil samples are taken at different sites all over Germany. The concentration of 30 PFAS - 13 carboxylic acids (C4-C18), 5 sulfonic acids (C4-C10) and 12 precursor substances) - is determined in these soil samples using three different sample preparation approaches: 1) ultrasonic extraction of the soil samples with Methanol; 2) preparation of eluates to test the leaching behaviour of the PFAS and 3) TOP assays following the method published by Houtz & Sedlak. Targeted LC-MS/MS is used to determine PFAS concentration after all three preparation steps. For the TOP-assay, the concentration of all 30 PFAS is compared prior to and after the oxidation reaction. Besides the ‘classic’ TOP-Assay, two other TOP-Assay approaches, the dTOP Assay and the photoTOP-Assay, are tested and the results of all three approaches are compared. First, all three TOP-Assay approaches will be tested on a reference soil spiked with a solution including all 30 PFAS measured in the project. Later, soil samples taken in the frame of the priorly described project will be tested. This poster will focus on the results of the experiments comparing the three different TOP Assay approaches in spiked reference soil. Additionally, some of the results of the other sample preparation methods, extraction and eluate preparation will be presented. T2 - FLUOROS 2023 CY - Idstein, Germany DA - 31.08.2023 KW - PFAS TOP Assay soil contamination PY - 2023 AN - OPUS4-58267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian T1 - EDC-WFD: A project to deliver reliable measurements for better monitoring survey and risks assessments. N2 - Monitoring programs should generate high-quality data on the concentrations of substances and other pollutants in the aquatic environment to enable reliable risk assessment. Furthermore, the need for comparability over space and time is critical for analysis of trends and evaluation of restoration of natural environment. Additionally, research work and exercises at the European level have highlighted that reliable measurements of estrogenic substances at the PNEC level are still challenging to achieve. The project EDC-WFD Metrology for monitoring endocrine disrupting compounds under the EU Water Framework Directive aims to develop traceable analytical methods for determining endocrine disrupting compounds and their effects, with a specific focus on three estrogens of the first watch list (17-beta-estradiol (17βE2), 17-alpha-ethinylestradiol (EE2), and estrone (E1)). Estrogens 17-alpha-estradiol (17E2) and estriol (E3) will be included to demonstrate the reliability of the developed methods and to support the requirements of Directive 2013/39/EC, Directive 2009/90/EC and Commission Implementation Decision (EU) 2018/840, hence improving the comparability and compatibility of measurement results within Europe. During the EDC-WFD project four selected effect-based methods (EBM) will be deeply investigated in order to improve their rationale use and their support in water quality assessment. In particular, the EBM sensitivity, specificity and accuracy on reference materials with single or mixture solutions of the five substances at a concentration of EQS values will be explored. This contribution will present the objectives and methods applied within the EDC-WFD project. T2 - EuChemS CY - Lisbon, Portugal DA - 29.08.2022 KW - WFD KW - Estrogens KW - Whole water samples KW - EQS PY - 2022 AN - OPUS4-57096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian T1 - A method for monitoring estrogens in whole surface waters by GC-MS/MS N2 - Natural and synthetic estrogens are key endocrine-disrupting chemicals. Despite occurring at ultra-trace levels (below ng L-1), it is believed that they are contributing to an increase in feminized fish and other endocrine disruptive effects, and hence, their inclusion in the Watch list was not unexpected. One of the main sources ofestrogens to surface waters is wastewater effluent. Once in surface waters, they can partition into different compartments, i.e., water and suspended particulate matter. For this reason, there is an urgent need for a methodology to monitor estrogen levels below the environmental quality standards (EQS) set by the Water Framework Directive requirements. In this study, a precise and accurate gas chromatography-mass spectrometry method (GC-MS/MS) for the analysis of estrone (E1), 17β-estradiol (17β-E2), 17α-estradiol (17α- E2), 17-alpha-ethinylestradiol (EE2), and estriol (E3) in whole water samples with ng L-1 limit of quantification (LOQ) was developed and validated in accordance with CEN/TS 16800:2020 guidelines. T2 - IMSC 2022 CY - Maastricht, Netherlands DA - 27.08.2022 KW - EDC KW - WFD KW - GC-MS PY - 2022 AN - OPUS4-57097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Konthur, Zoltán T1 - Enzyme-Based Electrochemical Detection of Fumonisins Applying Amperometric Sensing N2 - Fumonisins represent a class of toxic secondary metabolites produced primarily by Fusarium species, notably F. verticillioides and F. proliferatum, though Aspergillus niger can also produce these mycotoxins. They are most commonly found contaminating maize, but other grains are also at risk. Dietary exposure to fumonisins poses serious health risks to both humans and livestock, prompting the European Commission to set regulatory limits on their presence in food and animal feed. Traditional detection methods, such as chromatography, are often costly, are laboratory based and require specialized expertise. To address the need for simpler, more accessible detection methods, portable electrochemical biosensors present a promising solution. In this study, we introduce a novel enzymatic approach for fumonisin detection using amperometric sensing. Here, a recently discovered fumonisin amine oxidase (AnFAO) from Aspergillus niger, which catalyses the oxidative deamination of fumonisins and generates hydrogen peroxide, was produced recombinantly in Escherichia coli. In our hands, the enzyme exhibited higher specific activity toward Fumonisin B1 compared to Fumonisin B2 at the same substrate concentration (0.0037 U/mg and 0.0014 U/mg at 25 µM substrate, respectively). We demonstrated that enzyme activity correlates with both enzyme and substrate concentrations. To detect Fumonisin B1, the enzyme was covalently attached to magnetic particles, and hydrogen peroxide production was measured amperometrically in a flow injection system with Prussian blue carbon electrodes. This method enabled the quantification of Fumonisin B1 concentrations as low as 1.5 µM and proved that recombinant AnFAO effectively deaminated fumonisins even in its immobilized form. These results highlight AnFAO’s potential for developing an enzyme-based electrochemical biosensor to detect fumonisin contamination in food and feed products. T2 - ANAKON 2025 CY - Leipzig, Germany DA - 10.03.2025 KW - Immunoassay KW - Mycotoxin KW - Electrochemistry KW - Antibody KW - Biosensor PY - 2025 AN - OPUS4-63496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian T1 - Comparison of three different TOP Assay approaches for the determination of PFAS concentration in soil N2 - Within a project by the German Environmental Agency (Umweltbundesamt – UBA) soil samples are taken at different sites all over Germany. The concentration of 30 PFAS - 13 carboxylic acids (C4-C18), 5 sulfonic acids (C4-C10) and 12 precursor substances) - was determined in these soil samples using three different sample preparation approaches: 1) ultrasonic extraction of the soil samples with Methanol; 2) preparation of eluates to test the leaching behaviour of the PFAS and 3) TOP assays following the method published by Houtz & Sedlak. Targeted LC-MS/MS is used to determine PFAS concentration after all three preparation steps. For the TOP assay, the concentration of all 30 PFAS is compared prior to and after the oxidation reaction. Besides the ‘classic’ TOP assay, two other TOP assay approaches, the dTOP assay and the photoTOP assay, are tested and compared. First, all three TOP assay approaches will be tested on a reference soil spiked with a solution including all 30 PFAS measured in the project. Later, soil samples taken within the the priorly described project will were tested. This work is financed by the UBA via the ReFoPlan2021 project, FKZ372171. T2 - Euroanalysis 2025 CY - Barcelona, Spain DA - 31.08.2025 KW - PFAS KW - TOP-Assay KW - Soil PY - 2025 AN - OPUS4-64666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Langenhan, Jennifer T1 - PEGs in the human body: where they are coming from and what they are doing N2 - The general understanding has been that PEGs are biologically inert, meaning they pass the human body without any relevant reaction with anything. But recent studies have shown that migth not be correct. Here a retrospective analysis of LC-MS data was performed to determine correlations between blood PEG levels in humans and different experimental factors. T2 - Make and Measure 2021 CY - Online meeting DA - 16.09.2021 KW - PEG KW - Polyethylene glycole KW - Retrospective analysis PY - 2021 AN - OPUS4-53391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Exner, Thomas T1 - Spurenstoffe im Rohabwasser als Normalisierungsparameter N2 - Im Zuge der aktualisierten Kommunalabwasserrichtlinie (EU 2024/3019) bekommen u.a. Spurenstoffe und Krankheitsüberwachung eine erhöhte Aufmerksamkeit. Zum einen sollen ausgewählte Spurenstoffe zur zukünftigen Überwachung der Funktionalität der vierten Reinigungsstufe eingesetzt werden. Zum anderen ist europaweit die Infrastruktur einer Abwassersurveillance für mehrere Krankheitserreger zu gewährleisten. Letzteres wird seit 2022 in Deutschland mit den Projekten ESI-CORA und AMELAG mit wöchentlich je zwei Probennahmen auf 20 bis 170 Kläranlagen umgesetzt. In der vorliegenden Arbeit wurde geprüft, ob das Monitoring von Spurenstoffen zum Ausgleich von starken Schwankungen in der Viruslast verwendet werden kann (Normalisierung). T2 - 16. Langenauer Wasserforum (LWF) CY - Langenau, Germany DA - 17.11.2025 KW - Carbamazepin KW - Immunoassay KW - Anthropogene Marker KW - ELISA KW - Spurenstoffe PY - 2025 AN - OPUS4-64809 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -