title: Dissipation of oxytetracycline, chlortetracycline, tetracycline and doxycycline using HPLC-UV and LC/MS/MS under aquatic semi-field microcosm conditions.
abstract: A mixture of four tetracyclines; oxytetracycline (OTC), chlortetracycline (CTC), tetracycline (TC), and doxycycline (DC) was applied in fifteen 12000l outdoor microcosms at four treatment levels plus controls each with three replicates (n = 3). The dissipation times of parent compounds were monitored and half-lives (DT50) of 1-4 days, depending on treatment level were recorded. This is in accordance with half-lives from previous findings in bench-top experiments. Parent compound DT50, were determined using HPLC-UV. Furthermore, the samples were analyzed for ten different tetracycline products using LC/MS/MS. Two products were found for chlortetracycline; 4-epi-anh-chlortetracyline and the iso-chlortetracycline. Iso-forms were only found for CTC and only at the highest treatment (300 microg l(-1)). The half-lives, trajectories, and relative amounts of the products were analogous for all four tetracyclines. DT50 for products were less than 1.2 days. Formation of 4-epi-anh-tetracyclines, occurred at neutral to weak alkaline conditions.
authors.affiliation: University of Guelph, Centre for Toxicology, Bovey Building, Guelph, Ont., N1G 2W1, Canada. hsanderson@sdahq.org
authors.forename: Hans
authors.initials: H
authors.lastname: Sanderson
authors.forename: Flemming
authors.initials: F
authors.lastname: Ingerslev
authors.forename: Richard A
authors.initials: RA
authors.lastname: Brain
authors.forename: Bent
authors.initials: B
authors.lastname: Halling-Sørensen
authors.forename: Jim K
authors.initials: JK
authors.lastname: Bestari
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Wilson
authors.forename: David J
authors.initials: DJ
authors.lastname: Johnson
authors.forename: Keith R
authors.initials: KR
authors.lastname: Solomon
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring; D006207:Half-Life; D013754:Tetracyclines / Q000032:analysis* / Q000737:chemistry*; D014466:Ultraviolet Rays; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D013754:Tetracyclines; D014873:Water Pollutants