TY - JOUR A1 - Silva, C.P. A1 - Lima, D.L.D. A1 - Schneider, Rudolf A1 - Otero, M. A1 - Esteves, V.I. T1 - Evaluation of the anthropogenic input of caffeine in surface waters of the north and center of Portugal by ELISA N2 - This study comprises the development of an enzyme-linked immunosorbent assay (ELISA) for the quantification of caffeine in complex aqueous matrices without any sample clean-up procedure. Salinity and dissolved organic matter were selected as potential interfering agents. The addition of a sample buffer containing bovine serum albumin (BSA) prior to the sample was found to decrease the influence of those interfering agents. The working range of the developed method was 0.1–100 µg L- 1. Quantification of caffeine was possible in 43 out of 51 real aqueous samples, at values between < LOD and 15 µg L- 1. Results correlate well with those obtained by LC–MS/MS. To the best of our knowledge this is the first study dealing with the quantification of caffeine in Portugal's surface waters. KW - Caffeine KW - Surface water KW - ELISA KW - Anthropogenic markers KW - Koffein KW - Eintrag KW - Oberflächenwasser KW - Gewässer KW - Abwasser KW - Antikörper KW - Immunoassay PY - 2014 DO - https://doi.org/10.1016/j.scitotenv.2014.01.120 SN - 0048-9697 VL - 479-480 SP - 227 EP - 232 PB - Elsevier CY - Amsterdam AN - OPUS4-30450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silva, C.P. A1 - Lima, D.L.D. A1 - Schneider, Rudolf A1 - Otero, M. A1 - Esteves, V.I. T1 - Development of ELISA methodologies for the direct determination of 17beta-estradiol and 17alpha-ethinylestraydiol in complex aqueous matrices N2 - This study comprises the development of enzyme-linked immunosorbent assays (ELISAs) for the quantification of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in complex aqueous matrices without any sample clean-up procedures. Salinity and dissolved organic matter were selected as potential interfering agents in the analysis of E2 and EE2. The optimization was performed in order to (i) overcome matrix effects, and to (ii) increase sensitivity. The addition of a sample buffer containing bovine serum albumin (BSA) prior to the sample was found to decrease the influence of matrix effects. Moreover, adjustments of this buffer's pH together with the optimization of tracer (T) dilution and incubation time were undertaken in order to lower the quantification range. The optimized methods allowed the quantification of E2 and EE2 in the ranges 0.03–200 µg L-1 and 0.02–10 µg L-1, respectively. The assays were applied to real aqueous samples. It was possible to do a first approach to the levels of E2 in Portuguese surface and waste waters; however, it was not feasible to detect EE2 in the samples tested. KW - Enzyme-linked immunosorbent assay KW - Endocrine disrupting compounds KW - 17beta-Estradiol KW - 17alpha-Ethinylestradiol KW - Surface water KW - Wastewater PY - 2013 DO - https://doi.org/10.1016/j.jenvman.2013.03.041 SN - 0301-4797 SN - 1095-8630 VL - 124 SP - 121 EP - 127 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-28516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lima, D.L.D. A1 - Silva, C.P. A1 - Schneider, Rudolf A1 - Esteves, V.I. T1 - Development of an ELISA procedure to study sorption of atrazine onto a sewage sludge-amended luvisol soil N2 - Pesticides may contaminate ground and surface waters and one of the major factors governing this property is soil sorption. Sorption can be assessed by batch equilibrium technique which produces lots of extracts with high dissolved organic carbon concentration in which the pesticide concentration has to be determined. We developed an ELISA procedure to analyse atrazine based on polyclonal antibodies (C193) for which tracer structure and dilutions of immunochemical reagents were adapted to fit the purpose. After a 1000-fold dilution (or after an SPE clean-up procedure) extracts of a sewage-sludge amended luvisol (used as an example application of the methodology developed) could be reliably analysed. The Freundlich model is able to describe adsorption for this system (r² = 0.977) delivering a distribution coefficient KF of 1.6 ± 0.2 (mg kg-1) (mg L-1)-N and an isotherm nonlinearity factor N of 0.70 ± 0.09. KW - ELISA KW - Atrazine KW - Sorption PY - 2011 DO - https://doi.org/10.1016/j.talanta.2011.06.024 SN - 0039-9140 VL - 85 IS - 3 SP - 1494 EP - 1499 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-24305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lima, D.L.D. A1 - Schneider, Rudolf A1 - Scherer, H.W. A1 - Duarte, A.C. A1 - Santos, E.B.H. A1 - Esteves, V.I. T1 - Sorption-desorption behavior of atrazine on soils subjected to different organic long-term amendments N2 - Sorption of atrazine on soils subjected to three different organic amendments was measured using a batch equilibrium technique. A higher KF value (2.20 kg-1(mg L-1)-N) was obtained for soil fertilized with compost, which had a higher organic matter (OM) content. A correlation between the KFOC values and the percentage of aromatic carbon in OM was observed. The highest KFOC value was obtained for the soil with the highest aromatic content. Higher aromatic content results in higher hydrophobicity of OM, and hydrophobic interactions play a key role in binding of atrazine. On the other hand, the soil amended with farmyard manure had a higher content of carboxylic units, which could be responsible for hydrogen bonding between atrazine and OM. Dominance of hydrogen bonds compared to hydrophobic interactions can be responsible for the lower desorption capacity observed with the farmyard manure soil. The stronger hydrogen bonding can reduce the leaching of atrazine into drinking water resources and runoff to rivers and other surface waters. KW - Capillary electrophoresis KW - Atrazine KW - Sorption KW - Soil KW - Compost KW - Sewage sludge KW - Farmyard manure PY - 2010 DO - https://doi.org/10.1021/jf903937d SN - 0021-8561 SN - 1520-5118 VL - 58 IS - 5 SP - 3101 EP - 3106 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-21108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Filipe, O.M.S. A1 - Vidal, M.M. A1 - Scherer, H.W. A1 - Schneider, Rudolf A1 - Duarte, A. A1 - Esteves, V.I. A1 - Santos, E.B.H. T1 - Effect of long term organic amendments on adsorption-desorption of thiram onto a luvisol soil derived from loess KW - Thiram KW - Adsorption-desorption KW - Soil KW - Organic amendments PY - 2010 DO - https://doi.org/10.1016/j.chemosphere.2010.04.003 SN - 0045-6535 SN - 0366-7111 VL - 80 IS - 3 SP - 293 EP - 300 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-23196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -