Rapid Determination of Five Aflatoxins in Infant Milk Powder by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry-QuEChERS

A QuEChERS method combined with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been established for rapid determination of five aflatoxins in infant milk powder. After the sample was extracted by QuEChERS, and then purified by enhanced matrix removal lipid-dispersed solid phase extraction (EMR-Lipid dSPE). ACQUITY BEN C18 column(1.7 μm, 2.1 mm×100 mm) was selected for the separation. The qualitative and quantitative analyses were performed under the multiple reaction monitoring (MRM) acquisition mode, and an external standard method was used for the quantification. Under optimized analytical conditions, the analytes showed good linearities in concentration ranges of 0~1.6 ng/mL with their correlation coefficients (r) in ranges of 0.996 4~0.999 1. The limit of detection were 0.04~0.20 ng/g, the limit of quantitative were 0.58~0.95 ng/g, the spiked recoveries of low, medium and high for three concentration levels were 81.9%~103.2%, the relative standard deviations (RSD) of 2.2%~4.5%. The method has a good purification effect, and has the advantages of simple operation, accurate result, low detection limit and high sensitivity, which is suitable for the rapid detections of aflatoxin in infant milk powder.