Determination of chloramphenicol residues by reverse phase high performance liquid chromatography in foies gras

A reverse phase liquid chromatographic (LC) method for the determination of chloramphenicol (CAP) residues in foies gras was tested. The method was based on acetonitrile-sodium chloride extraction, sample clean-up with hexane and purification on a Sep-Pak C18 cartridge. Acceptable chromatographic separation was obtained for thawed samples with two sample clean-up steps with hexane, a purification step with acetonitrile + water (87.5 + 12.5) (v/v) before the elution of CAP residues by a mixture of acetonitrile + water (70 + 30) (v/v) with a chromatographic separation on Spherisorb ODS-2 (5 microns) column using sodium acetate buffer (pH 4.3) + acetonitrile (78 + 22) (v/v) as mobile phase. The detection limit of the method was 2.5 micrograms/kg. The mean recovery from spiked samples at the 10 micrograms/kg level was 55.7 +/- 8.7%.