Survey of cereal grains and soybeans for the presence of aflatoxin. 1. Wheat, grain sorghum, and oats.

Abstract

A total of 531 wheat samples, 533 grain sorghum samples, and 304 oat samples, representing all marketing grades, were analysed for the presence of aflatoxin. Samples were extracted by the procedure, slightly modified, developed by the Food and Drug Administration for the analysis of peanut and peanut products. Extracts were assayed for the presence of aflatoxins by thin-layer chromatography (TLC). The sensitivity limit of the analysis as carried out was 2-5 parts/billion of the metabolite. According to results of TLC, 2 wheat samples, 6 grain sorghum samples, and 3 oat samples, all in poorer grades, appeared to contain low levels of aflatoxin (2-19 parts/billion). Samples that were positive by TLC were tested in ducklings. No aflatoxin-like activity was detected in grain sorghum samples. Although the duckling test indicated that traces of toxins might be present in wheat and oat samples, more likely the test was negative. The sensitivity of the test as conducted was 1-2 parts/billion.