MIXED TOTAL DIET SLURRY AS A PROSPECTIVE REFERENCE MATERIAL

A total diet composite based on foods from the U.S. FDA Total Diet Stu dy was investigated to assess its suitability as a slurry material as a candidate reference material in the form of a slurry. Results for th e distribution of chlorine and sodium (overall variation 2 % for Na an d 3 % for Cl) indicated no serious problems of sedimentation. Similarl y determination of Co, Se, Rb, Sn, Fe and Zn covering an overall conce ntration (dry weight basis) range of 25 ng/g for Co to 33 mug/g for Fe and Zn, suggests that the homogeneity of the composite is reasonably good. However the operational steps adopted for this preliminary inves tigation were not optimal. Use of a high pressure diffusion type of ap proach adopted by the National Research Council of Canada in preparing the lobster hepatopancreas matrix (LUTS-1) should further improve the homogeneity characteristics of the slurry.