title: Precolumn derivatization technique for high-performance liquid chromatographic determination of penicillins with fluorescence detection.
abstract: A precolumn derivatization method was developed for the high-performance liquid chromatographic (HPLC) determination of penicillins using fluorescence detection. Penicillins were derivatized by a two-step reaction, the beta-lactam ring being opened by hydrolysis in aqueous sodium carbonate solution in the first step to give a secondary amine functionality, and the secondary amino group being reacted with 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole in the second step to give a fluorescent derivative. The resulting reaction mixture was injected directly onto a reversed-phase column and analysed by HPLC. At a penicillin concentration of 10 micrograms/ml, the precision (relative standard deviation) ranged from 1.49 to 2.20%. In the concentration range 0.2-100 micrograms/ml, a linear response was observed. The detection limits of this method were 30-85 ng/ml for five different penicillins at a signal-to-noise ratio of 3:1. The proposed method was applied to the determination of penicillins added to serum following pretreatment by deproteinization and removal of compounds containing amino functionalities with a cation-exchange resin.
authors.affiliation: School of Pharmacy, Hokuriku University, Ishikawa, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iwaki
authors.forename: N
authors.initials: N
authors.lastname: Okumura
authors.forename: M
authors.initials: M
authors.lastname: Yamazaki
authors.forename: N
authors.initials: N
authors.lastname: Nimura
authors.forename: T
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D002851:Chromatography, High Pressure Liquid; D010406:Penicillins / Q000097:blood*; D013050:Spectrometry, Fluorescence
chemical_list: D010406:Penicillins