Abstract

In this study, we developed simultaneous method for twenty-four compounds (sulfonamides, trimethoprim, ormetho- prim and dapsone) in variety of livestock products (beef, pork, chicken, egg, and milk) using LC-MS/MS with multiple reaction monitoring. To validate the method, five representative livestock products were evaluated at the three spiked levels considering the maximum residual limit (MRL) and limit of quantification (LOQ), 0.5 ×MRL, 1 × MRL, 2 × MRL, or 1 × LOQ, 2 × LOQ, 10 × LOQ. The samples are extracted with acetonitrile, dispersive solid phase extraction using MgSO 4 and sodium acetate with C 18 for effective clean up. As a result, recoveries ranged from 68.5 to 118.0%, coefficient variation was below 22%. Linearity was evaluated by correlation coefficients greater than 0.98. LOQ were ranged from 1 to 50 µg kg -1 . The results indicate that the proposed method is suitable for determining the sulfonamides, trimethoprim, ormethoprim and dapson in livestock products. This analytical method can be used for sulfonamide class routine monitoring in livestock products.