Submitted to: Journal of Association of Official Analytical Chemists International
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/9/2000
Publication Date: 12/1/2000
Citation: PARK, D.L., WHITAKER, T.B., GIESBRECHT, F.G., NJAPAU, H. PERFORMANCE OF THREE PNEUMATIC PROBE SAMPLES AND FOUR ANALYTICAL METHODS FOR THE ESTIMATION OF AFLATOXIN IN BULK COTTONSEED. JOURNAL OF ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS INTERNATIONAL. 2000. v. 83. p. 1270-1278. Interpretive Summary: Aflatoxin is a toxic and carcinogenic compound produced by fungi and is found in various agricultural commodities such as peanuts, corn, and cottonseed. The US Food and Drug Administration has set legal limits to control the maximum amount of aflatoxin found in food and feed products. As a result, agricultural industries will test commodities for aflatoxin at various locations in the market system in order to remove contaminated product from the food and feed chain. The aflatoxin test procedure used to quantify aflatoxin in bulk cottonseed lots is a three step process where a sample is taken from the lot (sample step), the sample is ground in a mill (sample preparation step), and the aflatoxin in the sample is quantified (analytical step). It is important to use sample equipment and analytical procedures that give accurate and precise results. The accuracy and precision of three sampling devices and four analytical methods were tested dand compared so that a specific aflatoxin test procedure can be recommende for detecting aflatoxin in cottonseed lots.
Technical Abstract: The requirement by the United States Food and Drug Administration that agricultural products susceptible to aflatoxin contamination contain no more than 20 parts per billion (ppb) 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 accumulation of three or more probings using a pneumatic probe. The official pneumatic probe's large size (7.6 x 127 cm) decreases in efficiency when sampling compacted cottonseed piles. Two smaller probes (1.9 x 127 cm and 1.9 x 254 cm) were therefore developed and tested for their suitability for sampling cottonseed piles. Furthermore, three rapid analytical methods (one thin layer chromatography and two immunochemical) were tested for suitability as on-site assay systems. An analysis of variance of the analytical test results showed no differences between the various probes tested. Of the rapid methods, however, only the aflatest-P immunoaffinity column gave results similar to the official AOAC-TLC method. In terms of safety, however, all methods prevent material contaminated above regulatory limits from reaching the consumer.