H_3PO_4-RhB-H_2O_2体系催化分光光度法测定痕量锡的研究

Study on Catalytic Spectrophotometric Determination of Trace Tin with H 3PO 4 RhB H 2O 2 System

基于稀 磷酸介质中存在 活化剂氯离子时，痕 量锡催化过 氧化氢氧 化罗丹明 Ｂ 的褪色 反应，建立 了测定痕量锡的催化分光光度法，研究了影响催化反应的动力 学条件。方法的检 出限为５．２×１０－ １ ２ ｇ／ｍ Ｌ，线性范围为０—９ｎｇ／２５ｍ Ｌ。用于人 发及水样中痕量锡的测定，结果令人满意。

A new catalytic spectrophotometric system for the determination of trace tin has been developed.The method is based on the catalytic effect of trace tin on oxidation of rhodamine B with hydrogen peroxide in dilute phosphoric acid medium and in the presence of Cl - as an activator.The kinetic conditions that influence the rate of catalytic decoloring reaction have been studied.The detection limit is 5.2×10 -12 g/mL and the linear range is 0—9ng/25mL.The method has been applied satisfactorily to the determination of trace tin in human hair and water samples.