MULTIFUNCTIONAL COLUMN COUPLED WITH LIQUID-CHROMATOGRAPHY FOR DETERMINATION OF AFLATOXINS B-1, B-2, G(1), AND G(2) IN CORN, ALMONDS, BRAZILNUTS, PEANUTS, AND PISTACHIO NUTS - COLLABORATIVE STUDY

An AOAC/IUPAC collaborative study was conducted to evaluate the effect iveness of a multifunctional column for the determination of aflatoxin s. The test portion is extracted with acetonitrile-water (9 + 1), the extract is filtered, and the filtrate is passed through the column. Th e aflatoxins in the eluate are determined by reversed-phase liquid chr omatography after derivatization with trifluoroacetic acid. Naturally contaminated corn, almonds, Brazil nuts, peanuts, and pistachio nuts s piked with total aflatoxins at 5, 10, 20, and 30 ng/g were sent to 12 collaborators in the United States, Denmark, France, Japan, and Switze rland. Eleven collaborators completed the study. Average recoveries of total aflatoxins for each spike level for the various commodities (ex cluding Brazil nuts at 5 ng/g) were 93, 97, 95, and 95%, respectively; the repeatability relative standard deviation (RSD(r)) ranged from 6. 0 to 23.2% and the reproducibility relative standard deviation (RSD(R) ) ranged from 12.0 to 69.4%. The multifunctional column coupled with a liquid chromatographic method for determination of aflatoxins in corn , almonds, Brazil nuts, peanuts, and pistachio nuts has been adopted f irst action by AOAC INTERNATIONAL.