Determination of 14 mycotoxins in Chinese patent medicines by HPLC-MS/MS after immunoaffinity purification

Objective: To develop a method to determine the content of aflatoxin B1(AFB1),aflatoxin B2(AFB2),aflatoxin G1(AFG1),aflatoxin G2(AFG2),HT-2 toxin(HT-2),T-2 toxin(T-2),ochratoxin A(OTA),fumonisin B1(FB1),fumonisin B2(FB2),zearalenone,α-zearalenol,β-zearalenol,α-zearalanol,β-zearalanol in Chinese patent medicines.Methods: The mycotoxins in with HPLC-MS/MS after twice extracted by PBS and methanol and purified by high selective immunoaffinity column.The mycotoxins were extracted by PBS firstly and by 70% methanol secondly.A certain amount of extraction solution was added to immunoaffinity column.The column was washed by 0.1% twain-PBS and water and eluted by methanol.The elution was dried under nitrogen,dissolved in 1 mL solution of mobile phase.The mycotoxins were separated on a Waters Xterra C18 MS(100 mm×2.1 mm,3.5 μm) and the flow rate of gradient elution was 0.3 mL per minute.The MS/MS was performed with multiple reaction monitoring(MRM) mode.Results: After optimization of extraction,separation of HPLC and conditions of mass spectrometry,the determined limits of the 14 mycotoxins were from 1.0 to 5.0 μg·kg-1.The average recoveries were from 75.7% to 97.9% when spiked at levels of 1.0 μg·kg-1,5.0 μg·kg-1 and 10.0 μg·kg-1.And the relative standard deviation of 6 repeated spiking experiments ranged from 5.3% to 13.8%.Conclusion: The method is rapid,sensitive and accurate,and suitable for determining these 14 mycotoxins in Chinese patent medicine.The detection limits of aflatoxins can meet the requirement of domestic and foreign limited.