Inexpensive,rapid screening method for aflatoxins in peanuts and peanut products

Surveys of major Brazilian foodstuffs demonstrated that peanuts and peanut products continue to be very susceptible to aflatoxin contamination. To prevent, or at least minimise, the problem the aflatoxins need to be monitored by a rapid and inexpensive screening method. The AOAC Romer method has been used and found highly reliable. However, the clean-up step utilises anhydrous FeCl₃ and basic CuCO₃ which are expensive and not readily available in Brazil. Thus, the extraction (with a mixture of 270 ml methanol plus 30ml 40 g litre^?1 aqueous KCl) and clean-up (150 ml 100 g litre^?1 aqueous CuSO₄) steps of the method of Soares and Rodriguez-Amaya (1985) were combined with the AOAC minicolumn to provide a rapid, inexpensive screening technique. Fifty-two sample lots of peanuts and peanut products were screened by this and Romer's method, and the results were in complete agreement: 28 samples were negative, four < 20 μg kg^?1, 12 in the range 20–50 μg kg^?1, three in the range 50–100 μg kg^?1 and 5 >100 μg kg^?1. The results also agreed well when the extracts obtained by the two methods were submitted to quantitative TLC.