Critical practicalities in sampling for mycotoxins in feed

The presence of mycotoxins, in particular aflatoxin B1 , can cause significant health problems as well as severe economic loss, and are therefore regulated with respect to maximum acceptable concentration for various feed- and foodstuffs. International regulatory authorities have recognized the importance of representative sampling, and sampling guidelines that only partly comply with the Theory of Sampling have been formulated. Practical guidance regarding sampling, including correct design and operation of sampling devices and explanations on how to develop sufficient sampling protocols are lacking in current guidelines. These are critical practicalities of main importance, especially when dealing with trace concentrations and/or concentrations that are irregularly distributed, as for mycotoxins. Heterogeneity characterization, which is necessary to be able develop valid sampling protocols or validation assessments of existing sampling operations, is currently not mentioned in the existing guidelines. This paper explains all critical practicalities with respect to sampling of mycotoxins for 1-D and 3-0 feed decision units. Correct design and use of sampling and mass reduction devices, as well as structural guidelines for correctly designing experimental heterogeneity characterizations are presented, allowing evaluation of sampling representativeness and determination of optimal number of increments per composite sample. Practical examples are given on how to extract information from variographic analysis and replication experiments, based on an extensive field trials performed to determine aflatoxin levels in various feed components.