Variability associated with testing shelled corn for fumonisin

Variances associated with sampling, sample preparation, and analytical step s of a test procedure that measures fumonisin in shelled corn were estimate d, The variance associated with each stop of the test procedure increases w ith fumonisin concentration. Functional relationships between variance and fumonisin concentration were estimated by regression analysis. For each var iance component, functional relationships were independent of fumonisin typ e (total, B1, B2, and B3 fumonisins). At 2 ppm, coefficients of variation a ssociated with sampling (1.1 kg sample), sample preparation (Romer mill and 25 g subsample), and analysis are 16.6, 9.1, and 9.7%, respectively, The c oefficient of variation associated with the total fumonisin test procedure was 45% and is about the same order of magnitude as that for measuring afla toxin in shelled corn with a similar test procedure.