β修正新光度法测定环境水中银

β CORRECTION SPECTROPHOTOMETRIC DETERMINATION OF SILVER IN ENVIRONMENTAL WATER

在酸性介质中，银（Ⅰ）与碘化钾和丁基罗丹明Ｂ（ＢＲＢ）反应、显色液由红色变紫色．本文研究β修正光度法定量痕量银，该方法能消除显色体系中过量ＢＲＢ干扰，提高分析准确度和精密度。２５ｍｌ溶液中，银在０─１μｇ／ｍｌ浓度范围内遵循Ｌａｍｂｅｒｔ－Ｂｅｅｒ定律。样品分析表明，银最低测定量０．０４ｍｇ／Ｌ，加标回收率９５．３─１０６％。

In acidic solution silver-ion(Ⅰ)can react with both butyl rhodamine B(BRB)andpotassium iodide(KI)to change such a colored solution from red into voilet. Vitamin C,thiureaand sodium citrate are found to be effective for masking other ions to increase the selectivity ofthis reaction. In this paper β correction spectrophotometry is studied to determine trace silver;The method can eliminate the interference of excase of BRB-KI colorant to increase analyticalsensitivity and decreaae errur.Experimental results show that in a solution of 25 ml ,concentra-tion range of 0一1 μg/ml of silver the relation of β correction absorbance(A_β)and silver( x )islinear and the minimum dctection concentration is 0.04μg/ml and the recovery is between 95.3一106%.