title: Removal of 30 active pharmaceutical ingredients in surface water under long-term artificial UV irradiation.
abstract: This study investigated the i) kinetics, and ii) proportion of photolysis of 30 relatively stable active pharmaceutical ingredients (APIs) during artificial UV irradiation for 28 d in ammonium acetate buffer, filtered and unfiltered river water. Buffer was included to control removal kinetics under stable pH conditions and without particulate matter. Dark controls were used to determine removal due to other processes than photolysis and calculate the proportion of photolysis of the total removal. The removal of each API in each matrix was determined using online solid phase extraction/liquid chromatography tandem mass spectrometry (online SPE/LC-MS/MS). Most APIs transformed during the 28 d of UV irradiation and the dark controls showed that photolysis was the major removal process for the majority of the APIs studied. The half-lives ranged from 6 h (amitriptyline) in unfiltered river water to 884 h (37 d, carbamazepine) in buffer. In unfiltered river water, the proportion of APIs with short half-lives (<48 h) was much higher (29%) than in the other matrices (4%), probably due to additional organic carbon, which could have promoted indirect photolysis. Furthermore, two APIs, memantine and fluconazole, were stable in all three matrices, while alprazolam was stable in buffer and unfiltered river water and four additional APIs were stable in buffer. Considering the relatively long-term UV-exposure, this study enabled the investigation of environmentally relevant half-lives in natural waters. Many APIs showed high persistence, which is environmentally concerning and emphasizes the importance of further studies on their environmental fate and effects.
authors.affiliation: Department of Chemistry, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Blum
authors.affiliation: Department of Chemistry, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Sara H
authors.initials: SH
authors.lastname: Norström
authors.affiliation: University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zatisi 728/II, 389 25 Vodnany, Czech Republic.
authors.forename: Oksana
authors.initials: O
authors.lastname: Golovko
authors.affiliation: University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zatisi 728/II, 389 25 Vodnany, Czech Republic.
authors.forename: Roman
authors.initials: R
authors.lastname: Grabic
authors.affiliation: Section for Infectious Diseases, Department of Medical Sciences, Uppsala University, 751 85 Uppsala, Sweden; Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden.
authors.forename: Josef D
authors.initials: JD
authors.lastname: Järhult
authors.affiliation: University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zatisi 728/II, 389 25 Vodnany, Czech Republic.
authors.forename: Olga
authors.initials: O
authors.lastname: Koba
authors.affiliation: Department of Chemistry, Umeå University, 901 87 Umeå, Sweden; Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, 901 87 Umeå, Sweden. Electronic address: hanna.soderstrom@umu.se.
authors.forename: Hanna
authors.initials: H
authors.lastname: Söderström Lindström
mesh_terms: D004355:Drug Stability; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006207:Half-Life; D007700:Kinetics; D004364:Pharmaceutical Preparations / Q000302:isolation & purification / Q000528:radiation effects*; D010782:Photolysis / Q000528:radiation effects*; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods; D013997:Time Factors; D014466:Ultraviolet Rays; D014867:Water; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000528:radiation effects*
chemical_list: D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Active pharmaceutical ingredients; Aquatic environments; Half-lives; Oseltamivir; Photolysis; Photostability