Determination of Melamine in Milk Food by High Performance Lquid Chromatography With DiodeArray Detection

Objective To establish a method for the determination of melamine in milk food by high performance liquid chromatography with diode array detection.Method The sample was extracted,and protein was precipitated,the supernatant was cleaned-up by solid-phase extraction;the melamine in the sample solution was separated with BioBasic SCX column,the acetonitrile-potassium dihydrogen phosphate(0.05mol/L,pH 3.0) as mobile phase and detected at 236 nm with a diode array detector.Results Melamin content ranging from 25-800μg/ml has a good linearity(r = 0.9999),the regression equation y = 0.1094x-0.049:RSD = 1.38%,the recoveries were 89.91-90.19 %,the limit of detection was 0.07mg/kg.Conclusion The method had a high sensitivity,precision,accuracy,and can be used for detemination of melamine in dairy food.