偶氮氯膦——mA分光光度法测定钢样及食盐中钡

Spectrophotometric Determination of Barium in Steel Sample and Table salt with CPAmA

在pH9.0的NH_3—NH_4Cl缓冲溶液中,Ba(Ⅱ)与间乙酰基偶氮氯膦(CPAmA)生成紫蓝色络合物。络合物的最大吸收位于635nm。络合物的组成Ba(Ⅱ):CPAmA为1∶4,表现摩尔吸光系数ε_(max)=1.95×10~41·mol^(-1)·cm^(-1),钡(Ⅱ)含量在0-3.2×10^(-3)g/L范围内遵守比尔定律。本法用于测定钢样及食盐中的钡,结果满意。

Barium reacts with m-acetylohlorophosphonazo(CPAmA) in the medium of NH_3-NH_4Cl(pH9.0) to form a viotet-blue Complex which has a maximum absorption at 635nm.The molar ratio of Ba(Ⅱ) to CPAmA is 1: 4.The apparent molar absorptivity is ε_(max)=l.95×10~4L ·mol^(-1)·cm^(-1).Beer's Law is obeyed over the range of 0—3.2×10^(-3)g/L for barium.The method has been applied to the determination of barium in Steel Sample and table salt.The results were Satisfactory.