A LC-MS /MS method was developed for the determination of ten sulfonamides residues in milk.The MS was operated in the positive ion mode using multiple reaction monitoring.The protein of the sample was separated by acetonitrile.The extract was concentrated under the stream of nitrogen.The analytes were separated on a reversed-phase column of ZORBAX SB-C18(5 μm,4.6 mm×150 mm i.d.) by using methanol-acetonitrile-0.2% formic acid 10 mmol/L ammonium acetate solution as the mobile phase and gradient elution.The limits of detection were 0.5 and 1.0 μg/L,respectively,and the recoveries were between 91% and 102%.
