Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-27639 Zeitschriftenartikel Grandke, Julia; Oberleitner, Lidia; Resch-Genger, Ute; Garbe, L.-A.; Schneider, Rudolf Quality assurance in immunoassay performance - comparison of different enzyme immunoassays for the determination of caffeine in consumer products 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. Berlin Springer 2013 Analytical and bioanalytical chemistry 405 5 1601 1611 10.1007/s00216-012-6596-0 2016-02-20 OPUS4-28860 Zeitschriftenartikel Grandke, Julia; Oberleitner, Lidia; Resch-Genger, Ute; Garbe, L.-A.; Schneider, Rudolf Quality assurance in immunoassay performance - carbamazepine immunoassay format evaluation and application on surface and waste water 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. Cambridge RSC Publ. Royal Society of Chemistry 2013 Analytical methods 5 15 3754 3760 10.1039/c3ay40702k 2016-02-20 OPUS4-27814 Posterpräsentation Oberleitner, Lidia Application and evaluation of carbamazepine immunoassays 2013 ANAKON 2013 ANAKON 2013 Essen, Germany 2013-03-04 2013-03-07 2016-02-20 OPUS4-28995 Posterpräsentation Oberleitner, Lidia Fluorescense Polarization Immunoassays for Caffeine 2013 Euroanalysis 2013 Euroanalysis 2013 Warsaw, Poland 2013-08-25 2013-08-29 2016-02-20 OPUS4-28946 Posterpräsentation Oberleitner, Lidia Fluorescense Polarization Immunoassays for Carbamazepine 2013 24th Symposium on Pharmaceutical and Biomedical Analysis 24th Symposium on Pharmaceutical and Biomedical Analysis Bologna, Italy 2013-06-30 2013-07-03 2016-02-20 OPUS4-29238 Posterpräsentation Oberleitner, Lidia Comparison of Heterogeneous and homogeneous Immunoassays 2013 Trends in Diagnostics Trends in Diagnostics Tübingen, Germany 2013-10-07 2013-10-09 2016-02-20 OPUS4-30516 Posterpräsentation Oberleitner, Lidia New monoclonal anti-carbamazepine antibody for application in fluorescence polarization immunoassays 2014 Analytica Conference 2014 Analytica Conference 2014 Munich, Germany 2014-04-01 2014-04-03 2016-02-20 OPUS4-34514 Posterpräsentation Oberleitner, Lidia Fluorescence polarization immunoassay - Fast Screening method for antibody characterization 2015 Tag der Biotechnologie Tag der Biotechnologie Berlin, Germany 2015-07-16 2016-02-20 OPUS4-32143 Posterpräsentation Oberleitner, Lidia Fluorescence polarization immunoassay - the fast alternative to ELISA 2014 Schnell, schneller, Optik - wie optische Technologien die Lebensmittel- und Umweltanalytik optimieren Schnell, schneller, Optik - wie optische Technologien die Lebensmittel- und Umweltanalytik optimieren Berlin 2014-11-27 2014-11-27 2016-02-20 OPUS4-39250 Dissertation Oberleitner, Lidia Immunochemical determination of caffeine and carbamazepine in complex matrices using fluorescence polarization Pharmacologically active compounds are omnipresent in contemporary daily life, in our food and in our environment. The fast and easy quantification of those substances is becoming a subject of global importance. The fluorescence polarization immunoassay (FPIA) is a homogeneous mix-and-read format and a suitable tool for this purpose that offers a high sample throughput. Yet, the applicability to complex matrices can be limited by possible interaction of matrix compounds with antibodies or tracer. Caffeine is one of the most frequently consumed pharmacologically active compounds and is present in a large variety of consumer products, including beverages and cosmetics. Adverse health effects of high caffeine concentrations especially for pregnant women are under discussion. Therefore, and due to legal regulations, caffeine should be monitored. Automated FPIA measurements enabled the precise and accurate quantification of caffeine in beverages and cosmetics within 2 min. Samples could be highly diluted before analysis due to high assay sensitivity in the low μg/L range. Therefore, no matrix effects were observed. The antiepileptic drug carbamazepine (CBZ) is discussed as a marker for the elimination efficiency of wastewater treatment plants and the dispersion of their respective effluents in surface water. The development of a FPIA for CBZ included the synthesis and evaluation of different tracers. Using the optimum tracer CBZ-triglycine-5-(aminoacetamido) fluorescein, CBZ concentrations in surface waters could be measured on different platforms: one sample within 4 min in tubes or 24 samples within 20 min on microtiter plates (MTPs). For this study, a commercially available antibody was used, which led to overestimations with recovery rates up to 140% due to high cross-reactivities towards CBZ metabolites and other pharmaceuticals. For more accurate CBZ determination, a new monoclonal antibody was produced. In this attempt, methods for improving the monitoring during the production process were successfully applied, including feces screening and cell culture supernatant screening with FPIA. The new monoclonal antibody is highly specific for CBZ and showed mostly negligible cross-reactivities towards environmentally relevant compounds. Measurements at non-equilibrium state improved the sensitivity and selectivity of the developed FPIA due to slow binding kinetics of the new antibody. Additionally, this measure enables for CBZ determination over a measurement range of almost three orders of magnitude. The comprehensively characterized antibody was successfully applied for the development of sensitive homogeneous and heterogeneous immunoassays. The new antibody made the development of an on-site measurement system for the determination of CBZ in wastewater possible. After comprehensive optimization, this automated FPIA platform allows the precise quantification of CBZ in wastewater samples only pre-treated by filtration within 16 min. Recovery rates of 61 to 104% were observed. Measurements in the low μg/L range are possible without the application of tedious sample preparation techniques. Different FPIA platforms including MTPs, cuvettes and tubes were successfully applied. For the choice of the right format, the application field should be considered, e.g. desired sample throughput, usage for optimization or characterization of antibodies or if a set-up for routine measurements is sought for. For high sample throughput and optimization, FPIA performance on MTPs is advantageous. The best results for the application to real samples were obtained using kinetic FP measurements in cuvettes. Berlin Bundesanstalt für Materialforschung und -prüfung (BAM) 2016 154 978-3-9818270-2-6 1 124 urn:nbn:de:kobv:b43-392506 http://creativecommons.org/licenses/by-nc-nd/3.0/de/deed.de 2017-02-27