Determination of chromium sesquioxide in faeces by a spectrophotometric method.

Chromium sesquioxide Cr2O3, present as a non-absorbable marker in faeces, may be determined spectrophotometrically as chromate ion in aqueous solution after ashing and alkaline fusion. Recovery of this substance is excellent. The method described is simpler, more suited to the clinical laboratory and less hazardous than previously reported methods.