Application of an instrumental neutron activation analysis procedure to analysis of food.

The capabilities of a relatively simple instrumental neutron activation analysis procedure were demonstrated by performing multielement analyses of 240 Food and Drug Administration Total Diet Studies food composites. The analytical results provide a comprehensive database for a wide range of food types. The procedure incorporates only two irradiations and counts, polyethylene packaging and no sample transfer after irradiation. Concentrations were determined for 19 elements, 16 of which were found in most composites. Detection limits were calculated for all food groups and are given for the 22 elements included in the quantitative analysis scheme. In a qualitative search for 18 additional elements for which no standards were run, none were detected in any of the composites. Specific factors such as interferences from the blank are discussed in regard to their effects on the uncertainties associated with the experimental data and the detection limits. Modifications to the procedure are also suggested for lowering the detection limits for specific elements.