Abstract: Objective To establish a solid phase extraction-high performance liquid chromatography-tandem mass spectrometry method for the determination of four types of Alternaria toxins in wheat flour. Methods The samples were extracted with acetonitrile-0.05 mol/L ammonium dihydrogen phosphate（50/50）,purified by HLB solid-phase extraction column,and eluted in gradient procedure using methanol-1 mmol/L ammonium bicarbonate aqueous solution as the mobile phase,separated by HSS T₃ chromatography column,detected by three quadrupole mass spectrometry,and quantified by internal standard method. Results The regression equation of the four types of Alternaria toxins showed a good linear relationship within the range of 0.2-50 ng/mL,with a correlation coefficient r>0.998. The recoveries ranged from 76.2% to 110.6%,the relative standard deviation（RSD） was 4.04%-8.74%,the detection limit was 0.02-0.75 μg/kg,and the quantification limit was 0.06-2.50 μg/kg. Conclusion This method has high sensitivity,good accuracy,detection limit,recovery and precision that meet the requirements of methodology. It is suitable for the determination of four types of Alternaria toxins in wheat flour.

Key words: Alteration toxin, Wheat flour, High performance liquid chromatography-tandem mass spectrometry, Solid phase extraction