Comparison of sampling approaches for grain lots
A number of different approaches exist for grain sample collation; this report outlines them briefly and provides an interpretation of the major differences (in terms of lot size, tolerances, sampling technique, sample size, rates, etc.). Without exception, the preferred approach to sampling is from flowing grain, i.e. during the loading and unloading of a lot. However it is also recognised that this is not always possible, and hence much discussion of procedures for the sample of static lots (barges, lorries) is included in the documents referenced. The actual range of numbers of samples recommended illustrates the different levels of pragmatism accepted by the various standards committees involved. Even within one organisation, large ranges occur: for ISO, for example, the number of sample increments required for grain shipments of up to 500 000 kg varies from 33 to 330, depending on the type of grain being sampled. More inconveniently, few of the procedures are justified explicitly on the basis of statistical assessment of the sampling problem. Furthermore, most guidelines acknowledge that the procedures are not effective in the sampling of heterogeneous (non-uniform) distributions, an assumption for which little basis currently exists with relation to the adventitious presence of GMO material in grain lots. Nevertheless, the international acceptance of these approaches provides a good initial basis for the sampling of grain lots for the detection of GMO material.
Bibliographic Reference: EUR 20134 EN (2002), pp.13. Euro: Free of charge
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Record Number: 200214757 / Last updated on: 2002-05-22
Original language: en
Available languages: en