1975 年 95 巻 1 号 p. 123-127
3, 4, 5, 6-Tetrachloro-3', 4', 5', 6'-tetrahydroxyfluoran methyl ester (I) formed a blue complex with silver (I) in the presence of excess 1, 10-phenpthroline (II) and polyvinylpyrolidone (PVP) in a neutral solution. The color was applied for spectrophotometric determination of Ag [I], CN-, I-, and S2O32-. The absorbance of I-II-Ag [I] solution was measured at 630 on or 650 nm against I-II solution for the determination of Ag [I]. The difference in the absorbance of I-II-Ag [I] solution and of I-, CN-, or S2O32- solution was measured at 630 nm against water for the determination of CN-, I-, and S2O32-. Linear calibration curves were obtained for 0 to 2.8 μg of Ag [I], 0 to 3.0 μg of CN-, 1.0 to 7.5 μg of I-, and 0 to 6.5 μg of S2O32- using I and II.