title: Oxidation of cetirizine, fexofenadine and hydrochlorothiazide during ozonation: Kinetics and formation of transformation products.
abstract: The efficiency of wastewater ozonation for the abatement of three nitrogen-containing pharmaceuticals, two antihistamine drugs, cetirizine (CTR) and fexofenadine (FXF), and the diuretic drug, hydrochlorothiazide (HCTZ), was investigated. Species-specific second-order rate constants for the reactions of the molecular, protonated (CTR, FXF) or deprotonated (HCTZ) forms of these compounds with ozone were determined. All three compounds are very reactive with ozone (apparent second order rate constants at pH 7: kO3,pH7 = 1.7·10(5) M(-1)s(-1), 8.5·10(4) M(-1)s(-1) and 9.0·10(3) M(-1)s(-1) for CTR, HCTZ and FXF, respectively). Transformation product (TP) structures were elucidated using liquid chromatography coupled with high-resolution tandem mass spectrometry, including isotope-labeled standards. For cetirizine and hydrochlorothiazide 8 TPs each and for fexofenadine 7 TPs were identified. The main TPs of cetirizine and fexofenadine are their respective N-oxides, whereas chlorothiazide forms to almost 100% from hydrochlorothiazide. In the bacteria bioluminescence assay the toxicity was slightly increased only during the ozonation of cetirizine at very high cetirizine concentrations. The main TPs detected in bench-scale experiments were also detected in full-scale ozonation of a municipal wastewater, for >90% elimination of the parent compounds.
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600, Dübendorf, Switzerland; Silesian University of Technology, Faculty of Power and Environmental Engineering, Environmental Biotechnology Department, PL-44100, Gliwice, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Borowska
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600, Dübendorf, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Bourgin
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600, Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, CH-8092, Zurich, Switzerland.
authors.forename: Juliane
authors.initials: J
authors.lastname: Hollender
authors.affiliation: Swiss Centre for Applied Ecotoxicology Eawag-EPFL, Überlandstrasse 133, CH-8600, Dübendorf, Switzerland.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Kienle
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600, Dübendorf, Switzerland. Electronic address: christa.mcardell@eawag.ch.
authors.forename: Christa S
authors.initials: CS
authors.lastname: McArdell
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600, Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, CH-8092, Zurich, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland. Electronic address: urs.vongunten@eawag.ch.
authors.forename: Urs
authors.initials: U
authors.lastname: von Gunten
mesh_terms: D017332:Cetirizine / Q000737:chemistry*; D002853:Chromatography, Liquid; D006852:Hydrochlorothiazide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D016593:Terfenadine / Q000031:analogs & derivatives* / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D017332:Cetirizine; D006852:Hydrochlorothiazide; D010126:Ozone; D016593:Terfenadine; D062065:Wastewater; D014874:Water Pollutants, Chemical; C093230:fexofenadine
keywords: High-resolution mass spectrometry; Kinetics; Ozonation; Second-order rate constant; Transformation products