Reverse phase high pressure liquid chromatographic determination of aflatoxins in foods.

A method for determining aflatoxins by high pressure liquid chromatography (HPLC) with fluorescence detection after CB extraction and cleanup has been applied to various foods. Recoveries at 1--15 ppb levels from green coffee and peanut butter was 72--85 and 74--104%, respectively. Precision of the method has been tested for peanut butter. Other products to which the method has been successfully applied include tree nuts, seeds, grains, chocolate-covered peanut butter candy, and roasted, salted-in-shell peanuts. High levels of aflatoxins found in several samples of nuts by this method have been verified by the official thin layer chromatographic (TLC) method. The advantages of this HPLC method are speed, precision, sensitivity, selectivity, and immediate chemical confirmation of aflatoxins B1 and G1. None of the products analyzed required special cleanup procedures. Preparative-scale HPLC was used to isolate purified B1 for toxicity testing.