title: Confirmatory assay for the simultaneous detection of five penicillins in muscle, kidney and milk using liquid chromatography-electrospray mass spectrometry.
abstract: A confirmatory assay using liquid chromatography-electrospray mass spectrometry (LC-EMS) is presented for the simultaneous determination of penicillins V and G along with oxacillin, cloxacillin and dicloxacillin in muscle, kidney and milk. Nafcillin is used as an internal standard. Samples are extracted using acetonitrile and cleaned up using liquid-liquid extraction into dichloromethane. The extracts are injected into a dedicated LC-EMS instrument and any penicillins present are detected using multiple single-ion monitoring. Three or four ions can be detected for each penicillin, meeting one of the recommended EU criteria for confirmatory residue analyses using low-resolution mass spectrometry. The detection limits are below the stipulated EU maximum residue limits for each of the penicillins.
authors.affiliation: Department of Agriculture, Veterinary Sciences Division, Belfast, UK.
authors.forename: W J
authors.initials: WJ
authors.lastname: Blanchflower
authors.forename: A S
authors.initials: AS
authors.lastname: Hewitt
authors.forename: D G
authors.initials: DG
authors.lastname: Kennedy
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004350:Drug Residues / Q000032:analysis*; D005260:Female; D007668:Kidney / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D008892:Milk / Q000737:chemistry*; D009132:Muscles / Q000737:chemistry*; D010406:Penicillins / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D010406:Penicillins