High-performance liquid chromatographic method for the rapid and simultaneous determination of sulfamonomethoxine, miloxacin and oxolinic acid in serum and muscle of cultured fish.

A rapid method for the simultaneous determination of sulfamonomethoxine (SMM), miloxacin (MLX) and oxolinic acid (OA) in serum and muscle of cultured fish by high-performance liquid chromatography has been developed. A Hisep shielded hydrophobic phase column (15 cm x 4.6 mm I.D.) and a mobile phase of 0.05 M citric acid-0.2 M disodium hydrogenphosphate buffer, pH 2.5 in 10 mM tetra-n-butyl ammonium bromide-acetonitrile (85:15) with ultraviolet detection at 265 nm were used. The recoveries of SMM, MLX and OA from serum and muscle samples were 72-101%. The detection limits of the three drugs were 0.05-0.1 microgram/ml or g of sample.