Simultaneous Determination of Quinolone Antibacterials in Fish and Meat by High Performance Liquid Chromatography

Abstract

A simple and selective high performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of quinolone antibacterials, which include oxolinic acid (OXA), nalidixic acid (NA), piromidic acid (PMA), miloxacin (MLX) and flumequine (FQ), in fish and meat.The drugs were extracted with 0.2% metaphosphoric acid-methanol (7:3), followed by a Bond Elut C18 clean-up procedure. The HPLC separation was carried out on an L-column ODS using 0.05M sodium dihydrogenphosphate-acetonitrile (6:4) as the mobile phase. A fluorescence detector was used for OXA, NA, MLX and FQ at the excitation wavelength of 325nm and the emission wavelength of 365nm, and an ultraviolet detector at 280nm for PMA. The calibration graphs were rectilinear from 1 to 20ng for each drug. The recoveries of drugs from fish and meat fortified at 0.5μg/g were 77.9-87.2%, with high precision. The limits of detection were 0.01μg/g for each drug. OXA was found in 7 samples of eel at levels in the range of 0.01-0.1μg/g. A photodiode-array detector was used to confirm identification of residual OXA in eel.