Applications of precision colorimetry to elemental microanalysis

The sample (< 1 mg) is burnt in an oxygen flask for the determination of rhenium. It is destroyed by a wet process in a Kjeldahl flask for the determination of rhodium or tellurium (sample < 4 to 5 mg) or zirconium (sample < 1.5 mg). These elements are determined spectrophotometrically. The following reactions are used: reduction of perrhenate by tin(II) chloride in the presence of 2,2'-furildioxime or thiourea, complexation of rhodium(III) by sodium hypochlorite, formation of iodotellurite, complexation of zirconium(IV) with Xylenol Orange. (author)