Hitoshi Nagai

Spectrophotometric determination of rare earth elements and thorium with arsenazo

Abstract The simultaneous spectrophotometric determination of rare earth elements (lanthanum and gadolinium) and thorium with arsenuzo is described. In 0.05 N nitric acid, thorium alone forms a colored complex with the reagent; at PH 7.2 both thorium and the rare carths form colored complexes. Satisfactory results were obtained with weight ratios of Th/rare earths ranging from 0.2 to 10.

Solvent extraction of manganese with thenoyltrifluoracetone

The formula of the manganese-TTA complex extracted with xylene from 0.5M sulphuric acid solution containing sodium bromate is MnT(3) where HT is the enol form of thenoyltrifluoracetone, TTA. The formula of the manganese-TTA complex extracted from slightly acid solution (pH 4-5) with acetone-benzene mixture is MnT(2). The extraction constants of the MnT(2) and MnT(3) systems are calculated to be 3 x 10(-7) and 1 x 10(3), respectively. The distribution ratios of TTA under various extraction conditions are given.

The composition of the zirconium-arsenazo complex

Abstract There is discordant information in the literature on the composition of the zirconium-arsenazo complex in solution. A detailed spectrophotometric study indicates that at pH 1.3, 1.7 and 3.5 the complex is formed by one mole of zirconium reacting with one mole of arsenazo (R), giving the empirical formula ZrR.

COMPOSITION OF THE SCANDIUM AND RAE EARTH COMPLEXES OF ARSENAZO

The empirical formula of the scandium(III) complex with arsenazo in solution was established by three spectrophotometric techniques: mole ratio method, continuous variation method, and slope ratio method. It is indicated that at pH 6.1(0.1M in acetate) the complex is formed by one mole of scandium reacting with one mole of arsenazo (R), giving the empirical formula as ScR. The results of the continuous variation method indicate that at pH 7.2 (0.1M in triethanolamine) arsenazo forms 1 to 1 complexes with the rare earths. Lanthanum(III), cerium(III), and ytterbium(III) we re used. (P.C.H.)

Spectrophotometric determinaion of traces of boron in high-purity bismuth

ビスマスを冷却材とする半均質炉の研究開発が現在日本原子力研究所において進められている.これに伴ないビスマス中のコン跡のホウ素の定量法が必要となった.ビスマス粉末試料を塩酸と臭素により溶解後過剰の臭素を加熱により除く.つぎにメタノールを加え,ホウ素をホウ酸メチルとして蒸留分離する.留出液は水酸化カルシウム懸濁液に捕集したのち蒸発乾固する.残分に一定量の塩酸と水を加えてからクルクミン法による吸光光度定量を行なう.0.1~1ppmのホウ素に対して回収率は少し低く,+10%の補正が必要である.この補正を行なえば,誤差は±0.1ppm B 以内と考えられる.