title: Structural considerations on the selectivity of an immunoassay for sulfamethoxazole.
abstract: Sulfamethoxazole (SMX), a sulfonamide, is a widely used bacteriostatic antibiotic and therefore a promising marker for the entry of anthropogenic pollution in the environment. SMX is frequently found in wastewater and surface water. This study presents the production of high affinity and selective polyclonal antibodies for SMX and the development and evaluation of a direct competitive enzyme-linked immunosorbent assay (ELISA) for the quantification of SMX in environmental water samples. The crystal structures of the cross-reacting compounds sulfamethizole, N(4)-acetyl-SMX and succinimidyl-SMX were determined by x-ray diffraction aiming to explain their high cross-reactivity. These crystal structures are described for the first time. The quantification range of the ELISA is 0.82-63µg/L. To verify our results, the SMX concentration in 20 environmental samples, including wastewater and surface water, was determined by ELISA and tandem mass spectrometry (MS/MS). A good agreement of the measured SMX concentrations was found with average recoveries of 97-113% for the results of ELISA compared to LC-MS/MS.
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Hoffmann
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany; Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Baldofski
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Hoffmann
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Flemig
authors.affiliation: Department of Chemistry & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Carla Patrícia
authors.initials: CP
authors.lastname: Silva
authors.affiliation: Department of Chemistry & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Valdemar I
authors.initials: VI
authors.lastname: Esteves
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Emmerling
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Panne
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany; Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany. Electronic address: rudolf.schneider@bam.de.
authors.forename: Rudolf J
authors.initials: RJ
authors.lastname: Schneider
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D000906:Antibodies / Q000276:immunology; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D006433:Hemocyanins / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D011817:Rabbits; D013387:Succinic Anhydrides / Q000737:chemistry; D013420:Sulfamethoxazole / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D053719:Tandem Mass Spectrometry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000276:immunology
chemical_list: D000900:Anti-Bacterial Agents; D000906:Antibodies; D013387:Succinic Anhydrides; D014874:Water Pollutants, Chemical; C031801:succinic anhydride; D006433:Hemocyanins; D006735:Horseradish Peroxidase; C032808:keyhole-limpet hemocyanin; D013420:Sulfamethoxazole
keywords: ELISA; Environment; Sulfamethoxazole; Sulfonamide; Surface water; Validation; Wastewater; Water samples; X‐ray structure