[Determination of nitrates and nitrites in animal products].

Meat is a complex medium in which nitrates and nitrites react by processes which are not well known. We do not know how to determine the quantities added, and estimating the residual doses depends on the analytic techniques studied. The analysis begins with extractions and purifications by various techniques described. A brief description is then given of 13 techniques for determining nitrites, 5 of which were applied successfully to meat products, and 18 techniques for determining nitrates, 12 of them suitable for meats. The references are given. The authors conclude by stressing the need for better knowledge of the effect of extraction and preparation techniques in order to give meaning to the results obtained.