偶氮溴磺(Ⅲ)与钡配合物的分光光度研究及应用

Spectrophotometric Studies on the Reaction between Bromosulfonazo(Ⅲ) and Ba(Ⅱ)

研究了偶氮溴磺（Ⅲ）与Ｂａ２＋配合物的光度特征和显色反应的最佳条件。在较宽的ｐＨ范围内，试剂与钡形成１∶１的蓝色配合物。稳定常数Ｋ＝２３６×１０４，λｍａｘ＝６５０ｎｍ，表观摩尔吸光系数ε＝１２４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ｂａ２＋浓度在６×１０－７～１×１０－４ｍｏｌ·Ｌ－１范围内遵守比耳定律。该法可满意地用于河水和自来水中Ｂａ２＋的测定。回收率在９６１％～１０１１％之间。相对标准偏差小于１５％。

A 1∶1 blue complex of bromosulfonazo(Ⅲ) and Ba(Ⅱ) was fromed in a wide range of acid media.The Stability constant of the complex was 2 36×10 4 and the apparent molar absorptivity was 1 24×10 5 Lmol -1 ·cm -1 at 650 nm.Beer law was obeyed in the range of 6×10 -7 ～1×10 -4 mol·L -1 for barium(Ⅱ).The developed method was applied to the determination of Ba(Ⅱ) in tap water and Yellow River water with satisfactory results.The average recovery of spiked Ba for different samples ranged from 96 1% to 101 1% and the RSD was less than 1 5%.