Determination of aflatoxin and zearalenone analogs in edible and medicinal herbs using a group-specific immunoaffinity column coupled to ultra-high-performance liquid chromatography with tandem mass spectrometry

Six aflatoxins (AFs; AF B₁, B₂, G₁, G₂, M₁ and M₂) and six zearalenone (ZEN) analogs (ZEN, zearalanone, α-zeralanol, β-zeralanol, α-zearalenol, and β-zearalenol) were simultaneously extracted from edible and medicinal herbs using a group-specific immunoaffinity column (IAC) and then identified by ultra-high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The IAC was prepared by coupling N-hydroxysuccinimide-activated Sepharose 4B Fast Flow gel with two group-specific monoclonal antibodies. The column capacities to six AFs and six ZEN analogs ranged from 100.2 ng to 167.1 ng and from 59.5 ng to 244.4 ng, respectively. The IAC-UPLC-MS/MS method was developed and validated with three different matrices (Chinese yam [Dioscorea polystachya], Platycodon grandiflorum and coix seed [Semen Coicis]). Recoveries of twelve analytes from edible and medicinal herbs were in the range of 64.7%-112.1%, with relative standard deviations below 13.7%. The limits of quantification were in the range from 0.08 μg kg^-1 to 0.2 μg kg^-1. The method was proven to be sensitive and accurate, and suitable for the determination of real samples.