Analysis and monitoring of chloramphenicol residues in food of animal origin in Slovenia from 1991 to 2000.

To prevent the illegal use of chloramphenicol (CAP), regulatory control of its residues in food of animal origin is essential. In Slovenia, the monitoring of CAP residues for statutory purpose started in 1991. The results of a 10-year period are presented. CAP residues were determined by capillary gas chromatography (GC) with electron capture detection (ECD) using meta-CAP as an internal standard (ISTD). Before chromatographic determination, analytes were derivatized by silylation. Overall, CAP recovery, adjusted for ISTD, was for bovine muscle tissue and raw cow's milk (in the region of 2-10 microg kg(-1)) 89 and 102%, respectively, and for whole eggs, 87% (in the region of 1-10 microg kg(-1)). The use of meta-CAP improved significantly the precision of the method. The detection limit for CAP was 1 microg kg(-1), which was sufficiently sensitive for routine use. A total of 1308 random samples of Slovenian origin were analysed from 1991 to 2000, covering all parts of the country. CAP was found only in one milk sample in 1997 at a concentration of 4.6 microg kg(-1).