title: Chlorination and oxidation of sulfonamides by free chlorine: Identification and behaviour of reaction products by UPLC-MS/MS.
abstract: Sulfonamides (SAs) are one class of the most widely used antibiotics around the world and have been frequently detected in municipal wastewater and surface water in recent years. Their transformation in waste water treatment plants (WWTP) and in water treatment plants (WTP), as well as, their fate and transport in the aquatic environment are of concern. The reaction of six sulfonamides (sulfamethoxazole, sulfapyridine, sulfamethazine, sulfamerazine, sulfathiazole and sulfadiazine) with free chlorine was investigated at a laboratory scale in order to identify the main chlorination by-products. A previously validated method, liquid chromatography/mass spectrometry, was used to analyse SAs and their chlorination by-products. At room temperature, pH 6-7, reaction times of up to 2 h and an initial concentration of 2 mg/L of free chlorine, the majority of SAs suffered degradation of around 65%, with the exception of sulfamethoxazole and sulfathiazole (20%). The main reaction of SAs with free chlorine occurred in the first minute.
authors.affiliation: iMed.UL (Institute for Medicines and Pharmaceutical Sciences, Portugal), Faculty of Pharmacy, University of Lisboa, Av. Prof. Gama Pinto, 2, 1649-003 Lisboa, Portugal.
authors.forename: Vanessa de Jesus
authors.initials: Vde J
authors.lastname: Gaffney
authors.affiliation: Empresa Portuguesa das Águas Livres, S.A. - EPAL, Direcção de Controlo de Qualidade da Água, Av. de Berlim, 15, 1800-031 Lisboa, Portugal.
authors.forename: Vitor Vale
authors.initials: VV
authors.lastname: Cardoso
authors.affiliation: Empresa Portuguesa das Águas Livres, S.A. - EPAL, Direcção de Controlo de Qualidade da Água, Av. de Berlim, 15, 1800-031 Lisboa, Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Benoliel
authors.affiliation: iMed.UL (Institute for Medicines and Pharmaceutical Sciences, Portugal), Faculty of Pharmacy, University of Lisboa, Av. Prof. Gama Pinto, 2, 1649-003 Lisboa, Portugal; Laboratory of Bromatology and Water Quality, Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 2, 1649-003 Lisboa, Portugal. Electronic address: calmeida@ff.ulisboa.pt.
authors.forename: Cristina M M
authors.initials: CM
authors.lastname: Almeida
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D054879:Halogenation; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D013418:Sulfamethazine / Q000737:chemistry; D000077589:Sulfathiazole; D013432:Sulfathiazoles / Q000737:chemistry; D013449:Sulfonamides / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013696:Temperature; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D002713:Chlorine; D013418:Sulfamethazine; D000077589:Sulfathiazole; D013432:Sulfathiazoles; D013449:Sulfonamides; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Chlorination; Chlorination by-products; Sulfonamides