Broad-spectrum immunoaffinity cleanup for the determination of aflatoxins B, B, G, G, M, M 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 B, B, G, G, M and M (AFB, AFB, AFG, AFG, AFM and AFM) 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 369ng/mL gel for AFB, AFB, AFG, AFG, AFM and AFM, 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 0.008-0.045μg/kg. Among 31 real samples analyzed, one sample was contaminated with AFB, AFB and AFM at levels of 0.483, 0.068 and 0.104μg/kg, respectively. The established method is simple, accurate, and can be effectively used to determine the aflatoxins in Ophiocordyceps sinensis and its pharmaceutical preparations.