Pb-XO配合物显色光度法测定水样中微量铅  

Spectrophotometric determination of trace lead in water samples with Pb(Ⅱ)-XO system

作　　者：肖锡林[1] 魏永卷[1] 薛金花[1] 袁玉坤[1] 王永生[1] 

机构地区：[1]南华大学公共卫生学院&化学化工学院,湖南衡阳421001

出　　处：《应用化工》2009年第2期296-299,共4页Applied Chemical Industry

基　　金：国家自然科学基金资助项目(20877038);湖南省自然科学基金(03JJY3030)

摘　　要：二甲酚橙是微量分析中一种很重要的光度显色剂，在pH6．0的磷酸-醋酸-硼酸缓冲溶液中，二甲酚橙与铅形成稳定的1：1红色配合物，导致吸光度的增强。研究了铅与三苯甲烷类染料二甲酚橙的显色反应体系，发现在波长580nm处吸光度的增强值与铅的加入量有很好的线性关系，据此建立了测定微量铅的新方法。该方法的摩尔吸光数为3．312×10^4L/（mol·cm），铅离子的浓度在0．075—1．2mg／L范围内符合比耳定律。方法简便、灵敏、选择性好，可广泛应用。Xylenol orange is a very important developer in mieroanalysis. Pb^2＋ Can react with XO to form a stable 1 ： 1 complex of red color in Britton-Robinson buffer of pH 6.0. Chromogenic reaction of Pb^2＋ -xylenol orange system was studied and a new spectrophotometric method for determining trace lead was established. The results showed that the maximum absorption wavelength is 580 nm. The apparent molar absorption coefficient is 3. 312 × 10^4 L/（ mol · cm）. As the Pb^2＋ concentration is in the range of 0. 075 × 1.2 mg/L, it follows the Beer＇ s Law. The method had several advantages such as few procedures, mild reaction conditions easy operation, low contamination and high yield of product. The method can generally to be used.

关 键 词：分光光度法 二甲酚橙 铅 

分 类 号：O657.3[理学—分析化学]