Important considerations in collecting and preparing crop samples for residue analysis

The residue contents of agricultural commodities are determined for the purpose of getting such data to support a petition for establishing tolerances for a pesticide chemical or for the purpose of finding out whether or not a certain lot of a commodity contains an illegal, above-tolerance residue level. Sampling is an important consideration in either case. However, in this paper, the intent is to deal with the former problem of collecting and preparing samples of a broad spectrum of crops treated with a pesticide chemical and grown in experimental plots. The approach to the problem is about the same in any case except for those aspects that are altered by the design of the experiment. Regardless of the end use, the validity and usefulness of a residue result hinge upon an intelligent and realistic approach to the problem of obtaining a reliable sample.