Sample Preparation

Abstract

Once an aggregate sample has been collected and the laboratory sample withdrawn (if the aggregate sample is larger than the required laboratory sample), the laboratory sample must be prepared for mycotoxin quantification. Since it is not practical to extract the mycotoxin from a large laboratory sample, the mycotoxin is usually extracted from a much smaller portion of product (test portion) taken from the comminuted laboratory sample. If the commodity is a granular product such as shelled corn, it is essential that the entire laboratory sample be comminuted in a suitable mill and thoroughly homogenized before a test portion is removed from it (Dickens and Whitaker 1982; Campbell et al. 1986). As stated above, it is necessary to grind/comminute the entire laboratory sample before a test portion can be taken for analysis. Figure 5.1 emphasizes the need to comminute a laboratory sample to be able to obtain a smaller particle size and therefore a more homogeneous distribution of the mycotoxins.