Rapid decomposition and analysis of refractory cerium (IV) oxide and cerium compounds by fusion with ammonium hydrogen sulfate

• Published in: BUNSEKI KAGAKU Vol. 47; no. 8; pp. 491 - 495
• Main Authors: KITAGAWA, Mayumi, MATSUMOTO, Ken
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society for Analytical Chemistry 1998
• Subjects: decomposition of cerium(IV) oxide; determination of cerium; fusion with ammonium hydrogen sulfate
• ISSN: 0525-1931
• DOI: 10.2116/bunsekikagaku.47.491

A simple and rapid method for the decomposition of refractory cerium compounds has been proposed. Cerium samples (CeO2, CeTiO4, CeZrO4 and ore) were decomposed by fusion with ammonium hydrogen sulfate, which was found to be a suitably powerful flux for dissolving various refractory cerium compounds. An accurately weighed sample (ca. 30100 mg) was placed in a dry Pyrex glass test-tube (16 mm o.d., 180 mm length). Ammonium hydrogen sulfate(ca. 3 g) was added to the tube and mixed with the sample by agitating the tube. The bottom of the test tube was gently heated along with a swirling motion over a small gas flame of a Bunsen burner with a fish-tail at a temperature of ca. 350450°C. Heating was continued until the yellow melt changed into a colorless, clear and translucent form. The cooled melt was dissolved in water. Cerium (IV) oxide was dissolved by heating for about 6 min; for cerium(IV) titanate and cerium(IV) zirconate it was about 10 min. Finally, the concentration of the cerium in the resulting solution was determined by absorption spectrophotometry or a redox titrimetric method. This method was successfully applied to various cerium compounds and ore. The cerium, titanium and zirconium in the samples were determined.