title: Simultaneous identification and determination of residual penicillins by use of high-performance liquid chromatography with spectrophotometric or fluorometric detectors.
abstract: Using 7 penicillins (amoxicillin, ampicillin, methicillin, penicillin G, oxacillin, cloxacillin, and dicloxacillin), simultaneous and direct determination of residual penicillins in biological samples was carried out by use of bioassay and high-performance liquid chromatography with spectrophotometric or fluorometric detectors. By use of assay medium seeded with penicillin-sensitive Micrococcus luteus (ATCC No. 9341) as a test organism, we were able to detect penicillins even at low concentrations. All penicillins treated with 10 U of penicillinase/ml did not produce inhibition zones by disk testing, even at a concentration of 100 micrograms of penicillin/ml/assay plate. Using a mobile phase of acetonitrile:methanol: 0.01M KH2PO4 (19:11:70, v/v/v; pH, 7.1), standard solutions of the penicillins were separated from each other by use of high-performance liquid chromatography analysis, producing symmetric peaks without tailing, each of which had a characteristic retention time. Simultaneous detection of residual penicillins in bovine serum, kidneys, and liver, for the 5 penicillins for which analysis was possible by use of the UV method, yielded recovery rates from 71.4 to 102.3%; for the 2 amino-penicillins, amoxicillin and ampicillin, which could only be detected by use of the fluorometric method, recovery rate ranged from 72.9 to 103%.
authors.affiliation: Department of Veterinary Public Health, Faculty of Agriculture, Miyazaki University, Japan.
authors.forename: C C
authors.initials: CC
authors.lastname: Hong
authors.forename: C L
authors.initials: CL
authors.lastname: Lin
authors.forename: C E
authors.initials: CE
authors.lastname: Tsai
authors.forename: F
authors.initials: F
authors.lastname: Kondo
mesh_terms: D000818:Animals; D001681:Biological Assay; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004350:Drug Residues / Q000032:analysis*; D005470:Fluorometry; D016982:Micrococcus luteus / Q000187:drug effects; D010406:Penicillins / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010406:Penicillins