1958 年 78 巻 4 号 p. 315-319
A rapid and simplified method for the determination of a micro-quantity of antimony was devised. A part of the decomposition of organic antimony compounds was modified to lessen its effect on later colorimetric procedure and simplified. Examination of the optimal acidity at which Sb5+ is stable in the decomposition solution indicated it to be 6M hydrochloric acid. The decomposition solution is extracted with isopropyl ether, which has been saturated with 6M hydrochloric acid, by which about 98% of Sb5+ is extracted by one procedure. The coloration reagent is the usual rhodamine B but not the ordinary aqueous solution but a solution in 1M hydrochloric acid since the aqueous solution would be affected by the acid present in the extract and excess of the reagent not bound with Sb5+ would color by itself, interfering in the coloration of the compound of Sb5+ and rhodamine B. Such colorimetric procedures in strong acidity, avoiding drastic change of reaction after decomposition, was found to give a satisfactory result.