Submitted to: International IUPAC Symposium on Mycotoxins and Phycotoxins
Publication Type: Book / chapter
Publication Acceptance Date: 1/10/2002
Publication Date: 7/21/2002
Citation: WHITAKER, T.B., HAGLER, W.M., JOHANSSON, A.S., GIESBRECHT, F.G., TRUCKSESS, M.W. SAMPLING SHELLED CORN FOR FUMONISIN. DEKOE, W.J., SAMSON, R.A., VAN EGMOND, H.P., GILBERT, J. SABINO, M., EDITORS. HAZEKAMP 2, 6707 HG WAGENINGEN, THE NETHERLANDS. INTERNATIONAL IUPAC SYMPOSIUM ON MYCOTOXINS AND PHYCOTOXINS IN PERSPECTIVE AT THE TURN OF THE MILLENIUM. 2002. P. 97-107. Interpretive Summary:
Technical Abstract: The statistical distribution known as the compound gamma function was studied for suitability in describing the distribution of sample test results associated with testing lots of shelled corn for fumonisins. Fumonisins B1 and B2 were quantified using liquid chromatography. Thirty-two 1.1 kg test samples were taken from each of 16 contaminated lots sof shelled corn. An observed distribution consisted of 32 sample test results for each lot. The mean total fumonisins concentration and the variance among the 32 sample test results along with the parameters for the compound gamma function were determined for each of the 16 observed distributions. The 16 observed distributions of sample fumonisin test results were compared to the compound gamma function using the Power Divergence (PD) test. The null hypothesis that the observed distribution could have resulted from sampling a family of compound gamma distributions was not rejected at the 5% significance level for 15 of the 16 lots studied. Parameters of the compound gamma distribution were calculated from the 32-fumonisin sample test results using the method of moments. Using regression analysis, equations were developed that related the parameters of the compound gamma distribution to fumonisin concentration and the variance associated with a fumonisin test procedure. Operating characteristic curves were developed for several fumonisin-sampling plans with different sample sizes and different accept/reject limits to demonstrate the use of the compound gamma function.