| A liquid chromatography-tandem mass spectrometric(LC-MS/MS) method was developed for the simultaneous determination of four spice,including vanillin,methyl vanillin,ethyl vanillin and coumarin in infant formula sample.The infant formula sample was extracted by ultraphonic extraction with methanol-water(1∶1),centrifuged and diluted with water,then cleaned up with HLB solid phase extraction.The separation was performed on a Xselect HSS T3 column(150 mm×2.1 mm,3.5 μm) using a gradient elution program with mobile phase of 0.1% formic acid solution and acetonitrile.The qualitative analysis was based on retention times and characteristic ion pairs consisting of one parent ion and two fragment ions of the analyte,and the quantitative analysis was performed by the internal standard method.The results indicated that a good separation of four compounds was obtained in 7 min.The calibration curves were linear in the range of 1.0-50.0 ng?mL-1 for vanillin,and 0.5-50.0 ng?mL-1 for rest of analytes,with correlation coefficients not less than 0.999 3.The limits of quantitation(LOQs) were 10.0 μg?kg-1 for vanillin and 5.0 μg?kg-1 for methyl vanillin,ethyl vanillin and coumarin.The average recoveries at three spiked levels ranged from 85.2% to 107.4% with RSDs not more than 5.7%.This method is simple,reliable and sensitive,and is suitable for the analysis of four spices in infant formula sample. |