ARS | Publication request: Sampling for Mycotoxins

Submitted to: Book Chapter
Publication Acceptance Date: November 19, 2003
Publication Date: August 6, 2004
Citation: Whitaker, T.B. Sampling For Mycotoxins, In: Mycotoxins In Food: Detection And Control, Eds: N. Magan And M. Olsen. Woodhead Publishing Limited, Cambridge, Uk, PP.704. 2004

Technical Abstract: It is difficult to obtain precise and accurate estimates of the true mycotoxin concentration of a bulk lot when using a mycotoxin-sampling plan that measures the concentration in a small portion of the bulk lot. A mycotoxin-sampling plan is defined by a mycotoxin test procedure and a defined accept/reject limit. A mycotoxin test procedure is a complicated process and generally consists of several steps: (a) a sample is taken from the lot, (b) the sample is ground (comminuted) in a mill to reduce particle size, (c) a subsample is removed from the comminuted sample, and (d) the mycotoxin is extracted from the comminuted subsample and quantified. Even when using accepted test procedures, there is variability associated with each step of the mycotoxin test procedure. Because of this variability, the true mycotoxin concentration in the lot cannot be determined with 100% certainty by measuring the mycotoxin concentration in a sample taken from the lot. The variability for each step of the mycotoxin test procedure, as measured by the variance statistic, is shown to increase with mycotoxin concentration. Sampling is usually the largest source of variability associated with the mycotoxin test procedure. Sampling variability is large because a small percentage of kernels are contaminated and the level of contamination on a single seed can be very large. Methods to reduce sampling, sample preparation, and analytical variability are discussed.