title: Determination of oxytetracycline and its degradation products by high-performance liquid chromatography-tandem mass spectrometry in manure-containing anaerobic test systems.
abstract: This paper describes the development of a HPLC-MS-MS (ESI) method with baseline separation of oxytetracycline, 4-epi-oxytetracycline, alpha-apo-oxytetracycline and beta-apo-oxytetracycline using an XTerra column and an MeOH-MilliQ-water (containing 8 mM formic acid) mobile phase. Limits of quantification for aqueous standards were in the range of 0.004 to 0.008 microM. The linear range tested was 0.003 to 0.5 microM and in one case up to 17 microM. An experiment simulating the degradation of oxytetracycline in manure was set up and free concentrations of the four antibiotics were determined during 6 months. Oxytetracycline (>0.02 microM) was observed up till 6 months after spiking. No important increase in free concentrations of the degradation products was observed.
authors.affiliation: Department of Analytical and Pharmaceutical Chemistry, Royal Danish School of Pharmacy, Universitetsparken 2, 2100, Copenhagen, Denmark. mlc@dfh.dk
authors.forename: Marie Louise
authors.initials: ML
authors.lastname: Loke
authors.forename: Sonja
authors.initials: S
authors.lastname: Jespersen
authors.forename: Rob
authors.initials: R
authors.lastname: Vreeken
authors.forename: Bent
authors.initials: B
authors.lastname: Halling-Sørensen
authors.forename: Jette
authors.initials: J
authors.lastname: Tjørnelund
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006868:Hydrolysis; D010118:Oxytetracycline / Q000378:metabolism*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013552:Swine; D013754:Tetracyclines / Q000378:metabolism*
chemical_list: D013754:Tetracyclines; D010118:Oxytetracycline