Determination of sulphonamide residues in cattle meats by the Charm-II system and validation with high performance liquid chromatography with fluorescence detection.

The purpose of this study was determination of sulphonamide residues (sulphanilamide, sulphadiazine, sulphathiazole, sulphamerazine, sulphamethazine, sulphamethoxazole, and sulphadimethoxine) in cattle meat by the Charm II technique and the validation of sulphonamide levels by high performance liquid chromatography with fluorescence detector (HPLC-FLD). Of 157 meat samples, 9 samples (5.73%) were found positive by the Charm II method. To make quantitative confirmation of sulphonamide content of positive samples, HPLC-FLD was used and four samples were confirmed as positive. In HPLC analysis, the limit of detection (LOD) was in the range 8-15 μg/kg and the limit of quantification (LOQ) was 13-25 μg/kg. Average recoveries of sulphonamides ranged from 44.6% to 81% with relative standard deviations below 6% (n=6). In conclusion, we consider that the results obtained in field screening by only using the Charm II system, as is common practice in Turkey and worldwide, are inadequate and thus the results should be confirmed by sensitive systems like HPLC.