A Routine Method for Simultaneous Determination of Three Classes of Antibiotics in Aquaculture Water by SPE-RPLC-UV

Abstract

This work describes a routine monitoring method for simultaneous determination of three classes of veterinary antibiotics (quinolones, sulfonamides, and tetracylines) in the aquaculture water. The selected eleven pharmaceuticals include four quinolones (enoxacin, ofloxacin, ciprofloxacin and lomefloxacin), four sulfonamides (sulfadiazine, sulfadimidine, sulfamethoxazole and sulfisoxazole) and three tetracyclines (tetracycline, chlortetracycline, and doxycycline). The entire procedures for pre-concentration by solid phase extraction (SPE) using Oasis HLB, and liquid chromatography-ultraviolet spectrometry (LC-UV) quantification were examined and optimized. The chromatographic separations were performed on a Kromasil 100-C18(250 mm×4.6 mm, 5 μm) column, using 0.1% (v/v) formic acid in water and acetonitrile as mobile phase with gradient elution, and 280 nm as the detective wavelength. The recovery efficiencies were found to be 85-117% for quinolones, 81-109% for sulfonamides, and 84-110% for tetracyclines at three spiking levels (5, 10 and 50 μg/L). The developed method was applied to real water samples collected from four aquafarms located in Yichang, Hubei Province, China. Three or four tested antibiotics were detected in all water samples, with concentrations ranging from 0.65 μg/L to 4.33 μg/L. The method is convenient and rapid, and provides a quantitative measurement of multi-residue antibiotics without complex and expensive analytical equipment.