Determination of melamine and sulbactam in raw milk and liquid milk by hydrophilic interaction chromatography tandem mass spectrometry

An analytical method was developed for the determination of melamine and sulbactam in raw milk and liquid milk using hydrophilic interaction chromatography tandem mass spectrometry ( HILIC-MS/MS) .The samples were extracted with 2%acetic acid solution, and the protein was precipitated with acetonitrile subsequently.The separations of melamine and sulbactam were carried out on an Acquity UPLC BEH HILIC column using ammonium acetate solution-acetonitrile as mobile phase.The target compounds were carried out in the multiple reaction monitoring ( MRM) mode by employing the external standard method.The quantitation limit of mlamine was10 μg/kg.The recovery of melamine was 85.4% ¹02.5%, with the RSD of 3.10%⁶.55%.The quantitation limit of sulbactam was 1.0 μg/kg.The recovery of sulbactam was 86.1% ¹04.3%, with the RSD of2.35% ⁵.37%.With the advantages of convenience, sensitivity, good recoveries and repeatability, the method was suitable for the detection of melamine and sulbactam in raw milk and liquid milk.