Broad-spectrum immunoaffinity cleanup for the determination of aflatoxins B1, B2, G1, G2, M1, M2 in Ophiocordyceps sinensis and its pharmaceutical preparations by ultra performance liquid chromatography tandem mass spectrometry

An ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 (AFB1, AFB2, AFG1, AFG2, AFM1 and AFM2) in Ophiocordyceps sinensis and its pharmaceutical preparations. A rapid and reliable immunoaffinity column containing a broad-spectrum monoclonal antibody for six aflatoxins was used for sample cleanup. Under the optimized conditions, the home-made immunoaffinity column capacity were about 315, 319, 292, 102, 444 and 369 ng/mL gel for AFB1, AFB2, AFG1, AFG2, AFM1 and AFM2, respectively. Recoveries for all tested aflatoxins ranged from 79.28% to 103.42% with relative standard deviation less than 8%. The limits of quantitation were in the range of 0.008-0.045 μg/kg. Among 31 real samples analyzed, one sample was contaminated with AFB1, AFB2 and AFM1 at levels of 0.483, 0.068 and 0.104 μg/kg, respectively. The established method is simple, accurate, and can be effectively used to determine the aflatoxins in Ophiocordyceps sinensis and its pharmaceutical preparations.