接触反応を利用する極微量チオシアン酸イオンの吸光光度定量

概要

論文の詳細を見る
Iodine does not react with sodium azide however, the following reaction is catalytically promoted in the presence of micro amounts of sulfur compounds. 2NaN_3+I_2 → 2NaI+3N_2 This catalytic reaction is applied to the photometric determination of trace amounts of thiocyanate ion. One milliliter of an aqueous solution (1X10^<-3>N in KIO_3 and 1X10^<-2> N in KI) and 0.5ml of the 1 N acetic acid are placed in a glass tube with a glass stopper. After standing this solution for 5 min at 25℃, 3ml of the sodium azide solution (20g/100ml) and 5ml of the sample solution containing this cyanate ions are added. Three minutes after the mixing 0.5ml of the 1 N potassium iodide solution is added. Then, the absorbance of the solution is measured at 350nm. By this method, the concentration range from 0.005ppm to 0.08ppm of thiocyanate ion in 5ml of the sample solution can be determined accurately. Fe(III), Cu(II), CN- and SO_3^<2-> interfere with the determination of thiocyanate ion.
社団法人日本分析化学会の論文
1975-12-10