Simultaneous Determination of Aflatoxins and Ochratoxin A in Bee Pollen by Low-Temperature Fat Precipitation and Immunoaffinity Column Cleanup Coupled with LC-MS/MS

A simple and sensitive method has been developed for simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, and AFG2) and ochratoxin A (OTA) in bee pollen. The analytes in the sample were extracted with a mixture of acetonitrile/water (60:40, v/v), using low temperature for fat precipitation, followed by immunoaffinity column cleanup of extracts. The mycotoxins were quantified using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with an electrospray ionization (ESI) and a triple quadrupole (QqQ) analyzer. Matrix effect, accuracy, and precision were evaluated and achieved good results calculated by matrix-matched calibration standards which reduced the influence of matrix effect. Recoveries at three levels were in the range of 74.3-96.5 % with RSD less than 10.0 %. The correlation coefficients (r (2)) of the five mycotoxins were higher than 0.997. The method showed high sensitivity with LOD below 0.05 mu g/kg.