[Determination of chloramphenicol residues with reverse-phase high pressure liquid chromatography. Use in a pharmacokinetic study in rainbow trout with confirmation by mass spectrometry].

A simple and rapid high-performance liquid chromatography (HPLC) method for the determination of chloramphenicol (CAP) residues in trout muscle tissue is described. After an acetonitrile-sodium chloride extraction followed by washing with hexane and purification through a Sep-Pak C18 cartridge, analysis is performed by reversed-phase HPLC on Spherisorb ODS-II (5 microgram) using water-methanol (1:1) as the mobile phase. The detection limit of the method is 5 micrograms/kg. The mean recovery from spiked muscle samples at the 10-micrograms/kg level is 56 +/- 7.4%. CAP residues are confirmed by gas chromatography-mass spectrometry at concentrations as low as 1 micrograms/kg. Residues were detected in trout muscle after oral administration during 15 days. On the tenth day after treatment, an average of CAP of less than 5 micrograms/kg was measured. No residues were detected after the twentieth day.