Performance of three pneumatic probe samplers and four analytical methods used to estimate aflatoxins in bulk cottonseed

The requirement by the U.S. Food and Drug Administration that agricultural products susceptible to aflatoxin contamination contain aflatoxin at levels less than or equal to 20 parts per billion for consumer-ready products has led to the establishment of inspection programs by various industries. In Arizona, cottonseed samples from 100 ton piles are collected by an accumula tion of 3 or more probings with a pneumatic probe. When sampling compacted cottonseed piles, the large official pneumatic probe (7.6 x 127 cm) decreas es in efficiency, Two smaller probes (1.9 x 127 cm and 1.9 x 254 cm)were th erefore developed and tested for their suitability for sampling cottonseed piles. Three rapid analytical methods (one thin-layer chromatographic and 2 immunochemical) were tested for suitability as on-site assay systems. An a nalysis of variance of the analytical test results showed no differences be tween the various probes tested. Of the rapid methods, however, only the Af laTest-P immunoaffinity column gave results similar to those of the officia l AOAC thin-layer chromatography method. In terms of safety, however, all m ethods prevent material contaminated above regulatory limits from reaching the consumer.