新银盐光度法测定磷酸氢钙中的微量砷

Determination of Trace Arsenic in Calcium Phosphate Dibasic by a New Silver Salt Spectrophotometry

以硝酸银－乙酸－聚乙烯醇－乙醇作为砷化氢吸收液，Ｚｎ－ＫＩ－ＳｎＣｌ２为还原体系的新银盐光度法测定了磷酸氢钙中的微量砷。Ａｓ３＋含量在０～７．５μｇ／５ｍＬ范围内服从比耳定律。应用于磷酸氢钙样品中Ａｓ含量测定，回收率９６％～１０３％，方法检出限为２．８８×１０－６ｇ／Ｌ，ＲＳＤ为０．９４％～５．５０％，测定结果与标准方法基本一致。

A New Sliver Salt Spectrophotometry for determination of trace arsenic in calacium phosphate dibasic is presented, in which the generated arsenic hydride is absorbed by an absorbing solution of silver nitrate acetic acid polyvinylol ethanol.Beers law is obeyed over the range of 0￣7.5μg/5mL of As(Ⅲ). This method has been used to determine arsenic calcium phosphate dibasic with recoveries of 96%￣103%. The detecton limit for As is 2.88×10 -6 g/L. The relative standard deviations are 0.94%￣ 5.50% . The results obtained are in agreement with those by standard method.