5—(P一二乙氨基苯)亚甲基若丹宁光度法测定银

Spectrophotometric Determination of Silver with 5-〔p-(diethylamino)benzylidene〕Rhodanine

报道了试剂 5— (P一二乙氨基苯 )亚甲基若丹宁 (DEABR)与银的显色反应。在pH =7 0的醋酸铵缓冲溶液中 ,TritonX - 1 0 0存在下 ,DEABR与Ag (Ⅰ )生成 2∶1的橙红色稳定络合物 ,λmax=490nm ,ε =2 932×1 0 4 L·mol- 1 ·cm- 1 ,银的含量在 0～ 50 μg/2 5mL内符合比尔定律。方法用于显影液和工业废水中微量银的测定 ,结果满意。

The color reaction of 5-〔p-(diethylamino)benzylidene〕 rhodanine (DEABR) with silver(Ⅰ) was reported.It was found that,in the presence of TritonX-100,the silver and DEABR would form an orange-red stable complex of molar ratio of 1∶2(ammonium acetate buffer soln)at pH 7. The apparent molar absorptivity was 2 932×10 4 L.mol -1 .cm -1 at the maximum absorption wavelength of 495 nm.Beer's law was found applicable in the silver content range of 0～50 μg/25 ml.Satisfactory results have been achieved in the determination of silver contained in developing agent and industrial wastewater.