Multi sulfonamide screening in porcine muscle using a surface plasmon resonance biosensor

A binding protein displaying broad-spectrum cross-reactivity within the sulfonamide group was used in conjunction with a sulfonamide specific sensor chip and a surface plasmon resonance biosensor to develop a rapid broad spectrum screening assay for sulfonamides in porcine muscle. Results for 40 samples were available in just over 5 h after the completion of a simple sample preparation protocol. Twenty sulfonamide compounds were detected. Acetylated metabolites were not recognised by the binding protein. Limit of detection (mean-three times standard deviation value when n = 20) was calculated to be 16.9 ng g−1 in tissue samples. Intra-assay precision (n = 10) was calculated at 4.3 %CV for a sample spiked at 50 ng g−1 with sulfamethazine, 3.6 %CV for a sample spiked at 100 ng g−1 with sulfamethazine, 7.2 %CV for a sample spiked at 50 ng g−1 with sulfadiazine and 3.1 %CV for a sample spiked at 100 ng g−1 with sulfadiazine. Inter-assay precision (n = 3) was calculated at 9.7 %CV for a sample spiked at 50 ng g−1 with sulfamethazine, 3.8 %CV for a sample spiked at 100 ng g−1 with sulfamethazine, 3.5 %CV for a sample spiked at 50 ng g−1 with sulfadiazine and 2.8 %CV for a sample spiked at 100 ng g−1 with sulfadiazine.