High-performance liquid chromatographic screening and confirmation methods for chloramphenicol residues in meat with off-line cartridge sample clean-up and on-line diode array UV-VIS detection.

Two high-performance liquid chromatography (HPLC) methods for the analysis and confirmation of residues of the antibiotic chloramphenicol in edible animal tissues are described. The first method consists of an aqueous extraction followed by purification through an Extrelut cartridge and toluene partition. With this simple and rapid method, meat samples can be screened at the 5 micrograms/kg level. The second, more comprehensive, method is based on ethyl acetate extraction, followed by purification through a silica Sep-Pak cartridge and partition with buffer-diethyl ether and water-toluene. Confirmation of positive peaks at the 10 micrograms/kg level is performed by diode array UV-VIS detection. The recoveries for the two methods at the 10 micrograms/kg level are 58 and 85% respectively, coefficients of variation 5-6%. With the confirmation method, glucuronide and sulphate conjugates can be determined. However, in a positive reference sample (pig) none was observed.