title: Determination of antibiotics from soil by pressurized liquid extraction and liquid chromatography-tandem mass spectrometry.
abstract: A method for the analysis of several macrolide and ionophore antibiotics, as well as tiamulin, from soil was developed using pressurized liquid extraction (PLE), reversed-phase liquid chromatography and atmospheric pressure chemical ionisation (APCI) tandem mass spectrometry (LC-APCI+-MS-MS). The analytes were extracted from soil by PLE in 30 min and the extracts were cleaned up by solid-phase extraction (SPE) on a diol SPE cartridge. Liquid chromatographic (LC) separation of the antibiotics was achieved in 35 min. Recovery experiments were performed using spiked soil and concentrations varying from 1 to 2000 microg/kg. By using a macrolide internal standard the recovery rates for the macrolides erythromycin and roxithromycin ranged from 43 to 94% (RSD 20-23%), for the ionophore salinomycin the recovery rate was 76% (RSD 29%), while the pleuromutilin tiamulin was completely recovered. The limits of detection ranged from 0.2 to 1.6 microg/kg. In soil samples a maximum concentration of 0.7 microg/kg tiamulin was found.
authors.affiliation: Institute of Environmental Research (INFU), University of Dortmund, Otto-Hahn Strasse 6 D-44227 Dortmund, Germany.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schlüsener
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
authors.forename: Kai
authors.initials: K
authors.lastname: Bester
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004224:Diterpenes / Q000032:analysis; D004355:Drug Stability; D004917:Erythromycin / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D009827:Oleandomycin / Q000032:analysis; D011714:Pyrans / Q000032:analysis; D011786:Quality Control; D015575:Roxithromycin / Q000032:analysis; D012987:Soil / Q000032:analysis*; D012997:Solvents; D013696:Temperature; D000095662:Polyether Polyketides
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; D004917:Erythromycin; D009827:Oleandomycin; D011714:Pyrans; D015575:Roxithromycin; D012987:Soil; D012997:Solvents; C010327:salinomycin; D000095662:Polyether Polyketides; C014224:tiamulin