Abstract:Set up a method of liquid chromatography-mass spectrometry/mass spectrometry （LC-MS/MS）to detect the acesulfame，cyclamate，aspartame，alitame，neotame，saccharin sodium in yogurt.The sample was extracted by formic acid-triethylamine buffer solution.Add some potassium ferrocyanide and zinc acetate then the protein will be precipitated，purified by HLB solid-phase，through Phenomenex XB-C18 chromatographic column for separation，with 0.1%（volume fraction）formic acid and methanol as mobile phase，then the separation of these 6 kinds of synthetic sweeteners within 3 minutes by gradient elution.In the negative ion mode，measured with the multiple reaction mode，when the external standard level with 10，25，50 μg/kg，the recovery rate can be 70.50%-102.10%，and the relative standard deviation can be 1.56%-4.83%.This method is fast，accurate and high sensitivity.It can be used in the determination of synthetic sweeteners in yogurt and other lactic acid bacteria beverage.