title: Liquid chromatographic determination of amoxicillin concentrations in bovine plasma by using a tandem solid-phase extraction method.
abstract: We report a means of determining amoxicillin in bovine plasma by liquid chromatography with UV detection at 235 nm. Purification and concentration of extracts were accomplished by a tandem solid-phase extraction procedure with two reversed-phase columns. Separation of amoxicillin from interferences was improved by the incorporation of a crown ether in the solvent systems used both for the solid-phase extraction and the final high-pressure liquid chromatography. Cefadroxil was added as an internal standard. The average recovery of amoxicillin from plasma (n = 23) was 78.2 +/- 3.0%, and the within-run and between-run coefficients of variation ranged from 1.8 to 7.0%. The detection limit was estimated at 0.1 microgram/ml. This method was used to determine amoxicillin in bovine plasma after intramuscular administration of the drug.
authors.affiliation: Laboratoria voor Medische Biochemie en voor Klinische Analyse, Rijksuniversiteit Gent, Belgium.
authors.forename: H J
authors.initials: HJ
authors.lastname: Nelis
authors.forename: J
authors.initials: J
authors.lastname: Vandenbranden
authors.forename: A
authors.initials: A
authors.lastname: De Kruif
authors.forename: A P
authors.initials: AP
authors.lastname: De Leenheer
mesh_terms: D000658:Amoxicillin / Q000097:blood* / Q000493:pharmacokinetics; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006207:Half-Life; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000658:Amoxicillin