Validation of a Biacore Method for Screening Eight Sulfonamides in Milk and Porcine Muscle Tissues According to European Decision 2002/657/EC

Sulfonamides are commonly used for prophylactic or therapeutic purposes in veterinary medicine. A maximum residue limit (MRL) for sulfonamides has been set at 100 microg/kg in milk and muscle. A multisulfonamide antibody was used for the development of 2 different Biacore protocols, one for the screening of milk samples, the other for muscle samples. Two different Biacore systems were used: Biacore X system (milk protocol), which is considered a research and development apparatus, and Biacore 3000 system (muscle protocol), which is a completely automated system used for high-throughput screening. This report describes the validation of semiquantitative immunological methods according to the European Decision 2002/657/EC "concerning the performance of analytical methods." The different performance characteristics (detection capability CCbeta, specificity/selectivity, precision, stability, and applicability) were determined in relation to the European Union MRL of 100 microg/kg for sulfonamides. The applicability of the method to porcine, bovine, and poultry muscle was studied. The detection capabilities CCbeta were calculated to be 40 microg/L in milk and 60 microg/kg in porcine, bovine, and poultry muscles. Eight different sulfonamides, of which 3 (sulfamethazine, sulfamerazine, and sulfadiazine) are authorized in France, were detected simultaneously, at or below the MRL level, with both Biacore systems.