Simultaneous Determination of Oxolinic, Nalidixic and Piromidic Acids in Fishes by High Performance Liquid Chromatography

Abstract

A high performance liquid chromatographic method for the simultaneous determination of oxolinic acid (OA), nalidixic acid (NA), and piromidic acid (PA) in fishes has been developed.The extraction and clean-up methods previously reported for analysis of NA could be applied to analysis of OA and PA. Except for the wavelength of UV detection, liquid chromatography was performed under the same conditions as used for analysis of NA. The UV detector was operated at 335nm in order to avoid interference in the chromatograms of fish extracts. Each compound was separated clearly in approximately 15min. The calibration curves were linear in the range from 1 to 50μg/ml.The recoveries of OA, NA, and PA added to fishes were 87.5-90.0, 85.0-86.3 and 74.5-77.2% and the coefficients of variation were 0.6-2.2, 0.8-2.0 and 0.5-2.1%, respectively. The detection limits of OA, NA, and PA were 0.03, 0.04 and 0.1μg/ml, respectively.