Méthode rapide de dosage de l'oxyde de chrome dans les aliments, les fèces et les contenus digestifs par titrage après oxydation nitro-perchlorique

Abstract

A new technique for the determination of Cr2O3 in samples used in digestibility experiments [animal] is presented. Organic matter is destroyed and Cr2O3 oxidized by a mixture of nitric and perchloric acids in a single operation. After a short ebullition with persulfate necessary to bring all chromium to the hexavalent state, the latter was directly titrated with Mohr''s salt. The proposed method is very rapid and precise and manipulations are reduced to a minimum. The use of the glass apparatus proposed by Chat completely eliminates the risks resulting from the use of perchloric acid.