SIMULTANEOUS DETERMINATION OF THIAMPHENICOL, FLORFENICOL, AND CHLORAMPHENICOL RESIDUES IN MUSCLES OF ANIMALS AND CULTURED FISH BY LIQUID-CHROMATOGRAPHY

A liquid chromatographic (HPLC) method for simultaneous determination of thiamphenicol, florfenicol and chloramphenicol residues in muscles of animals and cultured fishes was developed. The drugs are extracted from minced muscles with ethyl acetate, and the extract is evaporated to dryness. The residue is dissolved with 3% NaCl and partitioned with n-hexane. The drugs are extracted with ethyl acetate, and after evaporation of the solvent, the residue is cleaned up by Sep-Pak Florisil cartridge. HPLC analysis is carried out on Chromatorex ODS column, and the drugs are quantitated by UV detector at 225 or 270 nm. The average recoveries of thiamphenicol, florfenicol and chloramphenicol added to muscles at 0.1 ppm were more than 74.1%. The detection limit was 1 ng for each drug standard, which corresponded to 0.01 ppm in muscles.