An ultra performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was established for the determination of aflatoxins（AFB1

AFB2

AFG1 and AFG2）in aquatic feeds based on multi-component immunoaffinity column purification.The samples were ultrasonically extracted with 80%acetonitrile aqueous solution

then purified with a multi-component immunoaffinity column

finally analyzed by UPLC-MS/MS with electrospray ionization in positive ion mode（ESI+）under multiple reaction monitoring（MRM）mode and quantified by the external standard method.The separation was performed on an Acquity UPLC BEH C18 column by gradient elution with 0.1%formic acid-acetonitrile as mobile phases.Good linear responses were obtained in the concentration ranges of 2.25-22.5 ng/mL for AFB1 and AFG1

and 0.75-7.5 ng/mL for AFB2 and AFG2

with their correlation coefficients larger than 0.997

respectively.The limits of quantitation（LOQs） were 0.7 μg/kg for AFB1 and AFG1

and 0.2 μg/kg for AFB2 and AFG2

respectively.The average recoveries for AFB1 and AFG1 at a spiked level of 1.5 μg/kg

and AFB2 and AFG2 at a spiked level of 0.5 μg/kg ranged from 78.7%to 85.5%

with intra-day and inter-day relative standard deviations of 6.0%-6.5%and 6.6%-7.0%

respectively.The method was simple

rapid

sensitive and reliable

and was suitable for the determination of aflatoxins residues in aquatic feed samples.