臭化セチルトリメチルアンモニウムの存在下エリオクロムシアニンRによるウラン(VI)の吸光光度定量

Eriochrome Cyanine R reacts with uranium (VI) in a slightly acidic medium in the presence of cetyltrimethylammonium bromide to form a blue complex, which has its absorption maximum at about 610 nm. Maximum color development is obtained in the pH range from 5.3 to 5.9. The sensitivity is very high, the molar absorptivity being about 9 × 104 at 605 nm. Many of interfering cations can be masked by addition of a mixture of calcium (II) and cyclohexanediaminetetraacetic acid. The results obtained by the continuous variation method, which is carried out in the presence of excessive cetyltrimethylammonium bromide, indicate that a 1 : 2 (metal : ligand) complex is formed between uranium (VI) and Eriochrome Cyanine R.