PAN－PVAβ修正新光度法测定地表水中的微量锌

β-CORRECTION SPECTROPHOTOMETRIC DETERMINATION OF ZINC IN WATER:Zn(Ⅱ)-PAN-PVA COLORED SYSTEM

本文研究了ｚｎ（Ⅱ）与ＰＡＮ和ＰＶＡ在ＮＨ＿４Ｃｌ－ＮＨ＿４ＯＨ缓冲介质中的显色反应，提出在５２０ｎｍ处用β修正新光度法测定微量锌。该法可准确消除剩余显色剂的干扰，分析精密度、灵敏度和线性范围均比单波长高，修正吸光度（Ａ＿ｓ）与Ｚｎ（Ⅱ）浓度在０－１．４μｇ／ｍｌ符合比耳定律，检出限０．０２μｇ／ｍｌ，样品加标回收率／％９３－９６，方法适合环境水样中锌的测定。

The colour reaction Zn￣(2+) with PAN-PVA has been studied The red complex is formed in NH_4Cl-NH_4OH buffer solution of pH9.2-10.2.In this paperβ-correction spec-trophotometry was studied to determine trace Zn￣(2+) in environmental water.It can eliminate theinterference of excess colorant for increasing analytical sensitivity and accuracy.The experimen-tal results shows that the recovery is 93-96%and relative standard deviation(RSD)equals0.7-3.2%. The detection limit is 0.02 μg/ml.This method is suitable for analysis of environ-mental water samples.