title: Aquatic persistence of eight pharmaceuticals in a microcosm study.
abstract: The persistence of eight pharmaceuticals from multiple classes was studied in aquatic outdoor field microcosms. A method was developed for the determination of a mixture of acetaminophen, atorvastatin, caffeine, carbamazepine, levofloxacin, sertraline, sulfamethoxazole, and trimethoprim at microg/L levels from surface water of the microcosms using solid phase extraction and high-performance liquid chromatography-ultraviolet (HPLC-UV) and liquid chromatography tandem mass spectrometry (LC-MS-MS). Half-lives in the field ranged from 1.5 to 82 d. Laboratory persistence tests were performed to determine the relative importance of possible loss processes in the microcosms over the course of the study. Results from dark control experiments suggest hydrolysis was not important in the loss of the compounds. No significant differences were observed between measured half-lives of the pharmaceuticals in sunlight-exposed pond water and autoclaved pond water, which suggests photodegradation was important in limiting their persistence, and biodegradation was not an important loss process in surface water over the duration of the study. Observed photoproducts of several of the pharmaceuticals remained photoreactive, which led to further degradation in irradiated surface waters.
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Monica W
authors.initials: MW
authors.lastname: Lam
authors.forename: Cora J
authors.initials: CJ
authors.lastname: Young
authors.forename: Richard A
authors.initials: RA
authors.lastname: Brain
authors.forename: David J
authors.initials: DJ
authors.lastname: Johnson
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hanson
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Wilson
authors.forename: Sean M
authors.initials: SM
authors.lastname: Richards
authors.forename: Keith R
authors.initials: KR
authors.lastname: Solomon
authors.forename: Scott A
authors.initials: SA
authors.lastname: Mabury
mesh_terms: D006207:Half-Life; D008962:Models, Theoretical; D004364:Pharmaceutical Preparations / Q000032:analysis*; D010782:Photolysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical