Determination of traces of boron in sodium metal and sodium hydroxide by the ion exchange-photometric method

• Published in: Bunseki kagaku Vol. 20; no. 2; p. 193
• Main Authors: FUKASAWA, Tsutomu, YAJIMA, Kazuo, KANO, Shigeki, MIZUIKE, Atsushi
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Science and Technology Agency 27.01.1971
• ISSN: 0525-1931
• DOI: 10.2116/bunsekikagaku.20.193

Removal of sodium by cation-exchange followed by concentration of boron by anion-exchange is applied. to the photometric determination of as little as 0.01 ppm of boron in sodium metal or sodium hydroxide. About 5 g of sodium metal or 10 g of sodium hydroxide is dissolved in water, and the resulting solution (5 M NaOH, ca. 50 ml) is introduced onto a large column of strongly acidic cation-exchange resin (Amberlite CG-120, H-form, 100200 mesh, 35 mmφ × 180 mm) and a small column of strongly basic anionexchange resin (Amberlite CG-400, OH-form, 100200 mesh, 18 mmφ × 25 mm), in series, at a flow-rate of 58ml per min. The columns are washed with ca. 220 ml of water, and the boron adsorbed on the small column is then eluted with 10 ml of 1 M sodium hydroxide at a flow-rate of 1 ml per min. The first 2 ml fraction of the effluent is discarded, and the following 8-ml fraction is collected for the subsequent photometric determination with dianthrimide or with curcumin. An analysis requires 45hrs. The determination of ca. 0.01 ppb of boron in water is also described.