Analysis of Asian herbs for the presence of aflatoxins using AFLACARD TOTAL for screening and immunoaffinity columns for quantification

Abstract

  A method for the analysis of aflatoxins in a range of Asian herbs was developed using AFLACARD TOTAL, an antibody based card test after clean up with a solid phase column or with an immunoaffinity column. In this study ten types of herb were examined for aflatoxins B₁, B₂, G₁ and G₂ , using a number of different extraction methods and clean-up techniques prior to analysis with AFLACARD TOTAL. Results were confirmed using EASI-EXTRACT Aflatoxin immunoaffinity columns in conjunction with HPLC. Extractions using 80% methanol were effective for simple herbs and required only clean-up with a solid phase syringe column, provided in the test kit to remove pigments. For more complex samples, a 75% acetonitrile solution was required in conjunction with an immunoaffinity column prior to analysis with AFLACARD TOTAL in order to improve extraction and sample clean up. In all cases, except a few species, the screening results achieved with the card were in agreement with the HPLC results and recoveries were above 70% for all herbs.