DETERMINATION OF SIX KIND OF MYCOTOXINS IN GRAIN BY LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY

In order to overcome the disadvantages in detecting mycotoxins including long time consuming,low efficiency and high cost,in this work,we have developed a novel method with the advantages of low cost and detecting a variety of mycotoxins simultaneously in grains.Six kinds of mycotoxins including aflatoxin B₁,ochratoxin A,zearalenone,deoxynivalenol,fumonisin B₁and B₂were extracted from grain and purified using a composite immunoaffinity column and then detected by liquid chromatography mass spectrometry (LC-MS).In the extraction processes,mycotoxins in grain were firstly extracted using a mixed solution of acetonitrile,acetic acid and pure water (80:1:19,V/V),and then by another mixed solution of methanol and water (8:2,V/V).The composite immunoaffinity column was used to get rid of the impurities such as pigment,lipid and protein in the extract,and thus eliminated the influence of the matrix on the ionization efficiency of the mycotoxins.The six kinds of mycotoxins could be well separated with a reversed-phase analytical column in 20 mins using methanol as mobile phase A,and the mixed formic acid (0.1%,V/V) and 1 mmol/L ammonium acetate as mobile phase B.These mycotoxins showed a good linear relationship with R ²>0.995.The recoveries were between 75.6%-102.6%.The relative standard deviation in the batch was 3.8%-9.6% which meets the requirements of《GB/T 27404-2008 Criterion on quality control laboratories-Chemical testing of food》.These results indicated that this method is accurate,rapid,highly sensitive and suitable to detect mycotoxins in rice,wheat and other grains.