TY - JOUR A1 - Tressl, R. A1 - Wondrak, G. T. A1 - Garbe, L.-A. A1 - Krüger, Ralph-Peter A1 - Rewicki, D. T1 - Pentoses and Hexoses as Sources of New Melanoidin-like Maillard-Polymers KW - Model compounds for melanoidins KW - Pyrroles from pentoses and hexoses KW - Beta-dicarbonyl pathway of the Maillard reaction KW - Polycondensation KW - MALDI-TOF-MS analysis KW - Antioxidative activity of oligomeric model compounds PY - 1998 SN - 0021-8561 SN - 1520-5118 VL - 46 IS - 5 SP - 1765 EP - 1776 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-2159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grandke, Julia A1 - Resch-Genger, Ute A1 - Bremser, Wolfram A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Quality assurance in immunoassay performance-temperature effects N2 - Temperature is one factor that influences the performance of immunoassays. Most commonly all incubation steps of the immunoassay are performed at ambient temperature. To systematically study the influence of temperature deviations on assay parameters like signal variation coefficients, limit of detection and measurement range, direct competitive enzyme immunoassays for the determination of two anthropogenic markers, caffeine and carbamazepine, were run at different temperatures above and below room temperature during individual assay steps. The temperature during the competition step had the greatest impact on the assay sensitivity yielding changes in test midpoints by a factor of 10 to 15. For carbamazepine, the test midpoints varied from 36 ng L-1, 108 ng L-1 to 378 ng L-1 employing 4 °C, 21 °C, or 37 °C as incubation temperature, respectively. The edge effect can be minimized resulting in a good plate homogeneity with small variation coefficients, when the assay is performed at ambient temperature. KW - Immunoassay KW - Temperature effects PY - 2012 U6 - https://doi.org/10.1039/c2ay05918e SN - 1759-9660 SN - 1759-9679 IS - 4 SP - 901 EP - 905 PB - RSC Publ. CY - Cambridge AN - OPUS4-25740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grandke, Julia A1 - Oberleitner, Lidia A1 - Resch-Genger, Ute A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Quality assurance in immunoassay performance - comparison of different enzyme immunoassays for the determination of caffeine in consumer products N2 - Enzyme immunoassays with optical detection are amongst the most widely used bioanalytical tools. We defined seven parameters for the quality assessment of immunoassays that were addressed in a systematic study of direct and indirect immunoassays, using the enzymes horseradish peroxidase (HRP) and alkaline phosphatase (AP), the chromogenic substrates 3,3',5,5'-tetramethylbenzidine (TMB) and para-nitrophenyl phosphate, and the fluorescent substrates 3-(4-hydroxyphenyl)propionic acid and 4-methylumbelliferyl phosphate. The same monoclonal antibody against caffeine was used throughout the study. The four quality parameters regarding the standard curve were the test midpoint (sensitivity), the measurement range, the relative dynamic range of the signal, and the goodness of fit of the adjusted four-parameter logistic function. All HRP immunoassays showed a higher sensitivity compared to the AP assays. On the basis of all four criteria, it was established that the direct assay format is superior to the indirect format, the immunoassay using HRP TMB fulfilling all requirements best. In a second step, caffeine concentrations in 24 beverage and cosmetics samples were determined and three more quality parameters were assessed with this application. The direct HRP TMB assay showed one of the best intra- and inter-plate precisions and the best accuracy, defined by the correlation of results with those from the chosen reference method liquid chromatography tandem mass spectrometry (LC-MS/MS). Considering all criteria, HRP TMB seems to be the enzyme substrate system of choice preferably used in the direct assay format. KW - Enzyme immunoassay KW - Caffeine KW - Enzyme substrate KW - Competitive assay KW - Assay format KW - Direct KW - Indirect PY - 2013 U6 - https://doi.org/10.1007/s00216-012-6596-0 SN - 1618-2642 SN - 1618-2650 VL - 405 IS - 5 SP - 1601 EP - 1611 PB - Springer CY - Berlin AN - OPUS4-27639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Garbe, L.A. A1 - Würtz, A. A1 - Piechotta, Christian A1 - Tressl, R. T1 - The Peptide-catalyzed Maillard Reaction - Characterization of 13C Reductones N2 - The reaction pathways of amino acids and reducing sugars are now fully understood. The focus in the last few years, however, has turned to the reaction of peptides and proteins with reducing sugars. We have investigated the reaction of γ-aminobutanoic acid, the heptapeptide Nα-Acetyl-Lys-Lys-β-Ala-Lys-β-Ala-Lys-Gly, and the model protein β-casein in Maillard reactions with 1-13C arabinose. Characterization of 13C-labeled acetic acid and norfuraneol by gas chromatography–mass spectrometry and nuclear magnetic resonance revealed new formation pathways. The results demonstrate significant differences in the labeling pattern of the products depending on the amine used, indicating different formation pathways of acetic acid and norfuraneol. KW - Norfuraneol KW - 13C labeling KW - Pathway KW - Casein KW - Peptide PY - 2008 U6 - https://doi.org/10.1196/annals.1433.046 SN - 0077-8923 SN - 1749-6632 SN - 0094-8500 VL - 1126 SP - 244 EP - 247 PB - New York Academy of Sciences CY - New York, NY AN - OPUS4-18432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grandke, Julia A1 - Oberleitner, Lidia A1 - Resch-Genger, Ute A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Quality assurance in immunoassay performance - carbamazepine immunoassay format evaluation and application on surface and waste water N2 - Carbamazepine (CBZ) is one of the most frequently detected pharmaceuticals in water samples. For the determination of this anthropogenic marker, various immunoassay formats were tested and evaluated in order to identify the most suitable one. For these direct competitive assays, the analyte was labelled with the enzyme horseradish peroxidase (HRP) or alkaline phosphatase (AP), and seven substrates with specific detection properties were used. The quality criteria for the standard curves were fulfilled by all HRP assays and the chemiluminescence AP format. Furthermore, intra- and inter-plate coefficients of variation as a measure of the achievable precision were determined for the samples. The application of the AP assays to surface water was unfeasible due to CBZ concentrations below the quantifiable concentration range. Surface as well as waste water samples could be analyzed with the HRP assays. Here, the HRP assay employing the chromogenic substrate 3,3',5,5'-tetramethylbenzidine yielded the best results. PY - 2013 U6 - https://doi.org/10.1039/c3ay40702k SN - 1759-9660 SN - 1759-9679 VL - 5 IS - 15 SP - 3754 EP - 3760 PB - RSC Publ. CY - Cambridge AN - OPUS4-28860 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drzymala, Sarah A1 - Riedel, Juliane A1 - Köppen, Robert A1 - Garbe, L.-A. A1 - Koch, Matthias T1 - Preparation of 13C-labelled cis-zearalenone and its application as internal standard in stable isotope dilution analysis N2 - Pure U-[13C18]-labelled cis-zearalenone (cis-ZEA) has been prepared and characterised as internal standard (ISTD) for a reliable quantification of cis-ZEA in contaminated food and feed products. The cis-isomer of the naturally trans-configurated Fusarium mycotoxin zearalenone is often neglected. However, isomerisation easily occurs by exposure of ZEA to (UV-)light. Thus, the applicability of the new cis-ZEA ISTD was demonstrated in a long-term isomerisation study comparing naturally trans-ZEA-contaminated edible oil with spiked edible oil. To estimate the benefits of the newly prepared cis-ZEA ISTD, various approaches to quantify cis-ZEA by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) were compared. As a result, a significant bias was revealed if no appropriate cis-ZEA standards are used. Furthermore, the new ISTD was applied to the analysis of 15 edible oils by stable isotope dilution analysis in combination with HPLC-electrospray ionisation-MS/MS. One of the maize germ oils showed the presence of cis-ZEA above LOD (>0.3 µg/kg), whereas two out of 15 maize germ oils were found to be contaminated with trans-ZEA (range 17.0-31.0 µg/kg). KW - ZEA KW - Zearalenone KW - Isomerisation KW - Occurrence KW - Edible oil KW - SIDA KW - HPLC-MS/MS KW - Quantification KW - LC-MS/MS PY - 2014 U6 - https://doi.org/10.3920/WMJ2013.1610 SN - 1875-0710 SN - 1875-0796 VL - 7 IS - 1 SP - 45 EP - 52 PB - Wageningen Academic Publishers CY - Wageningen AN - OPUS4-30126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gärtner, Stefanie A1 - Carvalho, J.J. A1 - Emmerling, Franziska A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Polyclonal murine and rabbit antibodies for the bile acid isolithocholic acid N2 - Bile acids are relevant markers for clinical research. This study reports the production of antibodies for isolithocholic acid, the isomer of the extensively studied lithocholic acid. The IgG titer and affinity maturation were monitored during the immunizations of three mice and two rabbits. In both animal models, polyclonal antibodies with a high selectivity and affinity were produced. The development of a direct competitive ELISA with a test midpoint of 0.69 ± 0.05 µg/L and a measurement range from 0.09–15 µg/L is reported. Additionally, the crystal structure of isolithocholic acid is described for the first time. KW - ELISA KW - Crystal structure KW - Competitive assay KW - Immunization monitoring KW - 3ß-hydroxy-5ß-cholanic acid PY - 2015 U6 - https://doi.org/10.1080/15321819.2014.924419 SN - 1532-1819 SN - 1532-4230 VL - 36 IS - 3 SP - 233 EP - 252 PB - Taylor & Francis CY - Philadelphia, Pa. AN - OPUS4-31836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drzymala, Sarah A1 - Herrmann, Antje A1 - Maul, Ronald A1 - Pfeifer, Dietmar A1 - Garbe, L.-A. A1 - Koch, Matthias T1 - In vitro phase I metabolism of cis-zearalenone N2 - The present study investigates the in vitro phase I metabolism of cis-zearalenone (cis-ZEN) in rat liver microsomes and human liver microsomes. cis-ZEN is an often ignored isomer of the trans-configured Fusarium mycotoxin zearalenone (trans-ZEN). Upon the influence of (UV-) light, trans-ZEN isomerizes to cis-ZEN. Therefore, cis-ZEN is also present in food and feed. The aim of our study was to evaluate the in vitro phase I metabolism of cis-ZEN in comparison to that of trans-ZEN. As a result, an extensive metabolization of cis-ZEN is observed for rat and human liver microsomes as analyzed by HPLC-MS/MS and high-resolution MS. Kinetic investigations based on the substrate depletion approach showed no significant difference in rate constants and half-lives for cis- and trans-ZEN in rat microsomes. In contrast, cis-ZEN was depleted about 1.4-fold faster than trans-ZEN in human microsomes. The metabolite pattern of cis-ZEN revealed a total of 10 phase I metabolites. Its reduction products, α- and β-cis-zearalenol (α- and β-cis-ZEL), were found as metabolites in both species, with α-cis-ZEL being a major metabolite in rat liver microsomes. Both compounds were identified by co-chromatography with synthesized authentic standards. A further major metabolite in rat microsomes was monohydroxylated cis-ZEN. In human microsomes, monohydroxylated cis-ZEN is the single dominant peak of the metabolite profile. Our study discloses three metabolic pathways for cis-ZEN: reduction of the keto-group, monohydroxylation, and a combination of both. Because these routes have been reported for trans-ZEN, we conclude that the phase I metabolism of cis-ZEN is essentially similar to that of its trans isomer. As trans-ZEN is prone to metabolic activation, leading to the formation of more estrogenic metabolites, the novel metabolites of cis-ZEN reported in this study, in particular α-cis-ZEL, might also show higher estrogenicity. KW - Cis-ZEN KW - Phase I metabolism KW - LC-MS/MS KW - HRMS KW - Depletion kinetics PY - 2014 U6 - https://doi.org/10.1021/tx500312g SN - 0893-228X SN - 1520-5010 VL - 27 IS - 11 SP - 1972 EP - 1978 PB - Soc. CY - Washington, DC, USA AN - OPUS4-32071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oberleitner, Lidia A1 - Grandke, Julia A1 - Mallwitz, F. A1 - Resch-Genger, Ute A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Fluorescence polarization immunoassays for the quantification of caffeine in beverages N2 - Homogeneous fluorescence polarization immunoassays (FPIAs) were developed and compared for the determination of caffeine in beverages and cosmetics. FPIAs were performed in cuvettes in a spectrometer for kinetic FP measurements as well as in microtiter plates (MTPs) on a multimode reader. Both FPIAs showed measurement ranges in the µg/L range and were performed within 2 and 20 min, respectively. For the application on real samples, high coefficients of variations (CVs) were observed for the performance in MTPs; the CVs for FPIAs in cuvettes were below 4%. The correlations between this method and reference methods were satisfying. The sensitivity was sufficient for all tested samples including decaffeinated coffee without preconcentration steps. The FPIA in cuvettes allows a fast, precise, and automated quantitative analysis of caffeine in consumer products, whereas FPIAs in MTPs are suitable for semiquantitative high-throughput screenings. Moreover, specific quality criteria for heterogeneous assays were applied to homogeneous immunoassays. KW - caffeine KW - Decaffeinated coffee KW - Fluorescence polarization immunoassay KW - Homogeneous immunoassay KW - Quality assurance criteria PY - 2014 U6 - https://doi.org/10.1021/jf4053226 SN - 0021-8561 SN - 1520-5118 VL - 62 IS - 11 SP - 2337 EP - 2343 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-30613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baldofski, Stefanie A1 - Hoffmann, Holger A1 - Lehmann, Andreas A1 - Breitfeld, Stefan A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Enzyme-linked immunosorbent assay (ELISA) for the anthropogenic marker isolithocholic acid in water N2 - Bile acids are promising chemical markers to assess the pollution of water samples with fecal material. This study describes the optimization and validation of a direct competitive enzyme-linked immunosorbent assay for the bile acid isolithocholic acid (ILA). The quantification range of the optimized Assay was between 0.09 and 15 mg/L. The assay was applied to environmental water samples. Most studies until now were focused on bile acid fractions in the particulate phase of water samples. In order to avoid tedious sample preparation, we undertook to evaluate the dynamics and significance of ILA levels in the aqueous phase. Very low concentrations in tap and surface water samples made a pre-concentration step necessary for this matrix as well as for wastewater treatment plant (WWTP) effluent. Mean recoveries for spiked water samples were between 97% and 109% for tap water and WWTP influent samples and between 102% and 136% for WWTP effluent samples. 90th percentiles of intra-plate and inter-plate coefficients of variation were below 10% for influents and below 20% for effluents and surface water. ILA concentrations were quantified in the range of 33-72 mg/L in influent, 21-49 ng/L in effluent and 18-48 ng/L in surface water samples. During wastewater Treatment the ILA levels were reduced by more than 99%. ILA concentrations of influents determined by ELISA and LC-MS/MS were in good agreement. However, findings in LC-ELISA experiments suggest that the true ILA levels in concentrated samples are lower due to interfering effects of matrix compounds and/or cross-reactants. Yet, the ELISA will be a valuable tool for the performance check and comparison of WWTPs and the localization of fecal matter input into surface waters. KW - ELISA KW - LC-MS/MS KW - Bile acids KW - Fecal marker KW - Surface water KW - Wastewater PY - 2016 U6 - https://doi.org/10.1016/j.jenvman.2016.08.023 SN - 0301-4797 VL - 182 SP - 612 EP - 619 AN - OPUS4-37668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drzymala, Sarah A1 - Weiz, S. A1 - Heinze, J. A1 - Marten, S. A1 - Prinz, Carsten A1 - Zimathies, Annett A1 - Garbe, L.-A. A1 - Koch, Matthias T1 - Automated solid-phase extraction coupled online with HPLC-FLD for the quantification of zearalenone in edible oil N2 - Established maximum levels for the mycotoxin zearalenone (ZEN) in edible oil require monitoring by reliable analytical methods. Therefore, an automated SPE-HPLC online system based on dynamic covalent hydrazine chemistry has been developed. The SPE step comprises a reversible hydrazone formation by ZEN and a hydrazine moiety covalently attached to a solid phase. Seven hydrazine materials with different properties regarding the resin backbone, pore size, particle size, specific surface area, and loading have been evaluated. As a result, a hydrazine-functionalized silica gel was chosen. The final automated online method was validated and applied to the analysis of three maize germ oil samples including a provisionally certified reference material. Important performance criteria for the recovery (70–120 %) and precision (RSDr <25 %) as set by the Commission Regulation EC 401/2006 were fulfilled: The mean recovery was 78 % and RSDr did not exceed 8 %. The results of the SPE-HPLC online method were further compared to results obtained by liquid&–liquid extraction with stable isotope dilution analysis LC-MS/MS and found to be in good agreement. The developed SPE-HPLC online system with fluorescence detection allows a reliable, accurate, and sensitive quantification (limit of quantification, 30 µg/kg) of ZEN in edible oils while significantly reducing the workload. To our knowledge, this is the first report on an automated SPE-HPLC method based on a covalent SPE approach. KW - Dynamic covalent hydrazine chemistry (DCHC) KW - Maize germ oil KW - Food KW - Mycotoxin KW - ZEA KW - Isomerisation KW - Occurrence KW - Edible oil KW - SIDA KW - LC-MS/MS KW - Quantification PY - 2015 U6 - https://doi.org/10.1007/s00216-015-8541-5 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 12 SP - 3489 EP - 3497 PB - Springer CY - Berlin AN - OPUS4-33067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drzymala, Sarah A1 - Binder, J. A1 - Brodehl, Antje A1 - Penkert, M. A1 - Rosowski, M. A1 - Garbe, L.-A. A1 - Koch, Matthias T1 - Estrogenicity of novel phase I and phase II metabolites of zearalenone and cis-zearalenone N2 - Zearalenone and its cis-isomer, cis-zearalenone, are nonsteroidal mycotoxins that elicit an estrogenic response upon binding to the estrogen receptor. This study compares the estrogenicity of eleven congeners including novel metabolites as 15-OH-zearalenone, zearalenone-14-sulfate, α-cis-zearalenol and β-cis-zearalenol using the E-Screen assay. Overall, a change in the configuration from trans to cis retains significant estrogenic activity. In contrast, alterations of the aromatic moiety including hydroxylation and sulfation showed a markedly decreased estrogenicity when compared to zearalenone. KW - Zearalenone KW - Mycotoxin KW - MCF-7 KW - E-screen assay KW - Estrogenicity KW - Isomerization PY - 2015 U6 - https://doi.org/10.1016/j.toxicon.2015.08.027 SN - 0041-0101 SN - 1879-3150 VL - 105 SP - 10 EP - 12 PB - Elsevier CY - Oxford [u.a.] AN - OPUS4-34167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oberleitner, Lidia A1 - Eremin, S.A. A1 - Lehmann, Andreas A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Fluorescence polarization immunoassays for carbamazepine - comparison of tracers and formats N2 - For the antiepileptic drug and anthropogenic marker carbamazepine (CBZ), a fast and cost-effective immunoassay based on fluorescence polarization (FPIA) was developed. The required fluorophore conjugates were synthesized from different fluorescein and CBZ derivatives. The most suitable tracer was CBZ–triglycine–5-(aminoacetamido)fluorescein. Additionally, the applicability of the assay in tubes and on microtiter plates was tested. The first format can be performed in a portable instrument and therefore can be applied in field measurements. The measurement of an individual sample can be carried out within 4 min. This assay shows a measurement range of 2.5–1000 µg L-1 and a test midpoint (or IC50) of 36 µg L-1. The FPIA performed on microtiter plates is useful for the assay development and is suitable for a very high throughput (up to 24 samples in 20 min). The test midpoint of this assay is 13 µg L-1 and the measurement range is 1.5–300 µg L-1. Furthermore, this assay requires smaller sample volumes and less reagents, including the crucial amount of antibody. The applicability of both assays to spiked surface water samples was evaluated. The recovery rates vary between 66–110% on microtiter plates and 81–140% in tubes. PY - 2015 U6 - https://doi.org/10.1039/c5ay00617a SN - 1759-9660 SN - 1759-9679 VL - 7 IS - 14 SP - 5854 EP - 5861 PB - RSC Publ. CY - Cambridge AN - OPUS4-33821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oberleitner, Lidia A1 - Dahmen-Levison, U. A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Application of fluorescence polarization immunoassay for determination of carbamazepine in wastewater N2 - Carbamazepine is an antiepileptic drug that can be used as a marker for the cleaning efficiency of wastewater treatment plants. Here, we present the optimization of a fast and easy on-site measurement system based on fluorescence polarization immunoassay and the successful application to wastewater. A new monoclonal highly specific anti-carbamazepine antibody was applied. The automated assay procedure takes 16 min and does not require sample preparation besides filtration. The recovery rates for carbamazepine in wastewater samples were between 60.8 and 104% with good intra- and inter-assay coefficients of variations (less than 15 and 10%, respectively). This automated assay enables for the onsite measurement of carbamazepine in wastewater treatment plants. KW - On-site measurement KW - Wastewater treatment plant KW - Fluorescence polarization immunoassay KW - Assay optimization KW - Mix-and-read assay PY - 2017 U6 - https://doi.org/10.1016/j.jenvman.2017.01.063 SN - 0301-4797 SN - 1095-8630 VL - 193 SP - 92 EP - 97 PB - Elsevier Ltd. AN - OPUS4-39152 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 U6 - 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 - JOUR A1 - Baldofski, Stefanie A1 - Canitz, C. A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Studies on the development of antibodies for the highly hydrophobic plasticizers DINCH and DEHT N2 - Diisononylcyclohexane-1,2-dicarboxylate (DINCH) and di-2-ethylhexyl terephthalate (DEHT), two of the most important substitutes for phthalate plasticizers, are used for a wide range of applications. Consequently, an increasing occurrence in urine and environmental samples is reported. Reliable and fast analytical methods for the quantification of these plasticizers are needed. So far, mainly GC-MS or LC-MS methods are used. We aimed to develop the first antibodies and immunoassays allowing for high-throughput analysis of samples. We designed two DINCH hapten structures and one DEHT hapten structure and employed hapten-protein conjugates for the immunization of rabbits. Sensitive competitive enzyme-linked immunosorbent assays (ELISAs) against each hapten using the produced polyclonal antibodies were established. Yet, binding of DINCH to the respective antibodies was not observed in neither direct nor indirect assay formats, even when using protein conjugates with the heterologous haptens and different carrier proteins in the indirect format. The use of surfactants and solvents in the sample buffer did not result in recognition of the plasticizers. Also, no binding of DEHT in ELISA employing the respective antibodies was detected. We speculate that the production of antibodies against these highly hydrophobic molecules is not possible via our route, however a different hapten design could overcome this obstacle. KW - Weichmacher KW - Phthalate KW - Antikörper KW - Selektivität KW - Ersatzstoffe KW - Polyclonal antibodies KW - Phthalate substitutes KW - Antibody production for hydrophobic molecules KW - DEHT KW - DINCH KW - Hapten design PY - 2018 U6 - https://doi.org/10.1016/j.ab.2017.12.006 SN - 0003-2697 VL - 543 SP - 90 EP - 96 PB - Elsevier Inc. CY - Amsterdam, NL AN - OPUS4-44015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Stephan A1 - Hanelt, S. A1 - Canitz, C. A1 - Hoffmann, Holger A1 - Garbe, L.-A. A1 - Schneider, Rudolf T1 - Entwicklung monoklonaler Antikörper gegen Diclofenac N2 - Diclofenac (DCF) wird als nicht-steroidales, antientzündliches Arzneimittel gegen Fieber, Entzündungen, rheumatische Erkrankungen und Schmerzen eingesetzt. 70 % werden nach Einnahme wieder ausgeschieden. Aufgrund unvollständiger Elimination in den Kläranlagen lassen sich Rückstände im Trinkwasser und im Oberflächengewässer nachweisen. Diclofenac wird in der Umweltanalytik v.a. mittels GC-MS oder LCMS nachgewiesen. Bioanalytische Methoden machen sich die spezifische Antigen-Antikörper-Wechselwirkung zunutze, so z.B. Immunoassays. Die hierfür erforderlichen Antikörper werden durch Immunisierung mit einem Konjugat aus dem Analyten und einem Trägerprotein gewonnen. Die Kopplung kann direkt über die Carboxylfunktion von Diclofenac erfolgen. Um Abschirmungseffekte zu vermeiden, kann zwischen Protein und Analy1 ein Spacer sinnvoll sein. PY - 2015 SN - 1618-3258 SN - 1617-5301 IS - 4 SP - 107 EP - 109 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-35241 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Rudolf A1 - Schmidt, S. A1 - Hanelt, S. A1 - Canitz, C. A1 - Hoffmann, H. A1 - Garbe, L.-A. T1 - Synthetic Strategies for the Modification of Diclofenac N2 - For many heterogeneous sensor applications as well as the synthesis of hapten antigens to produce antibodies, protein conjugates of the target substance are essential. A requirement is that the target substance already offers or is modified to contain a functionality that allows for coupling to a protein, that is, an amino acid residue. Ideally, to avoid shielding of the compound by the carrier protein, a sufficient distance to the protein surface should be provided. With its carboxyl function diclofenac (DCF) allows for direct binding to lysine residues after in situ synthesis of the NHS ester. One problem is that diclofenac as free acid tends to autocondensation, which results in low yields. Here we describe the 'insertion' of a C6 spacer via synthesis of the amide with 6-aminohexanoic acid. To carry out the reaction in solution, first the methyl ester of the amino acid had to be produced. Due to otherwise low yields and large cleaning efforts, solid-phase synthesis on Fmoc Ahx Wang resin is recommended. The crude product is mainly contaminated by cleavage products from the resin which were removed by chromatography. The structure of the highly pure hapten was completely determined by nuclear magnetic resonance (NMR) spectroscopy. KW - Diclophenac KW - Hapten synthesis KW - Solid-phase synthesis PY - 2017 U6 - https://doi.org/10.1055/s-0036-1588858 SN - 0936-5214 VL - 28 IS - 15 SP - 1984 EP - 1989 PB - Georg Thieme Verlag AN - OPUS4-43316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oberleitner, Lidia A1 - Garbe, L.-A. A1 - Dahmen-Levison, Ursula A1 - Schneider, Rudolf T1 - Improved strategies for selection and characterization of new monoclonal anticarbamazepine antibodies during the screening process using feces and fluorescence polarization immunoassay N2 - Immunoassays are suitable tools for high-throughput screenings. The prerequisite for accurate determinations by these methods is the selection of an excellent antibody. The production and selection of monoclonal antibodies is usually a tedious process. In this study, new strategies for improving antibody production and characterization were applied. This includes the monitoring of the immunization progress in mice through antibodies extracted from feces, which allows a time-resolved and animal-friendly monitoring of the immune response. Additionally, fluorescence polarization immunoassay (FPIA) could be successfully applied for fast and easy examination of cell culture supernatants and the investigation of antibody/antigen interactions including kinetics and fluorescence properties. These methods simplify the selection of the optimal antibody. As a target analyte, carbamazepine was chosen. This is a widely used antiepileptic drug which also frequently occurs in the environment. The new antibody enables CBZ determination in the concentration range 0.66–110 µg L-1 within 10 min using a high-throughput microtiter plate-based FPIA, and between 1.4 and 79 µg L-1 within 5 min applying an automated cuvette-based FPIA instrument, and from 0.05–36 µg L-1 using ELISA. The measurements were performed at a non-equilibrium state which improved the sensitivity and selectivity of the assays. Due to low cross-reactivity especially towards the main CBZ metabolite and other pharmaceuticals (<1%), this antibody gives the opportunity for application in medical and environmental analyses. KW - Antikörper KW - Emerging Pollutants KW - Schadstoffe KW - Monoklonal KW - Pharmazeutika KW - Arzneistoffe KW - Assay KW - Pesticide parathion-methyl KW - Waste-water KW - Samples KW - Pharmaceuticals KW - Quantification PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-392473 SN - 1759-9660 VL - 8 SP - 6883 EP - 6894 PB - Royal Society of Chemistry CY - London AN - OPUS4-39247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -