Determination of Aflatoxin B₁ in Grains by Aptamer Affinity Column Enrichment and Purification Coupled with High Performance Liquid Chromatography Detection

Aflatoxin B-1 (AFB(1)) is a highly teratogenic and carcinogenic secondary metabolite produced by Aspergillus. It is commonly detected in agricultural products such as cereals, peanuts, corn, and feed. Grains have a complex composition. These complex components severely interfere with the effective extraction and separation of AFB(1), and also cause problems such as matrix interference and instrument damage, thus posing a great challenge in the accurate analysis of AFB(1). In this study, an aptamer affinity column for AFB(1) analysis (AFB(1)-AAC) was prepared for the enrichment and purification of AFB(1) from grain samples. AFB(1)-AAC with an AFB(1)-specific aptamer as the recognition element exhibited high affinity and specificity for AFB(1). Grain samples were enriched and purified by AFB(1)-AAC, and subsequently analyzed by high performance liquid chromatography with post-column photochemical derivatization-fluorescence detection (HPLC-PCD-FLD). The average recoveries of AFB(1) ranged from 88.7% to 99.1%, with relative standard deviations (RSDs) of 1.4-5.6% (n = 3) at the spiked levels of 5.0-20.0 mu g kg(-1). The limit of detection (LOD) for AFB(1) (0.02 mu g kg(-1)) was much below the maximum residue limits (MRLs) for AFB(1). This novel method can be applied to the determination of AFB(1) residues in peanut, corn, and rice.