茜素紫-铬(Ⅵ)-十六烷基三甲基溴化胺体系显色反应的研究及应用  

Study on the color reaction of alizarin violet-Cr(Ⅵ)-CTMAB system and its application

作　　者：樊静[1,2] 尚晓博[1] 李霞[1] 马献涛[1] 崔凌云[1] 

机构地区：[1]河南师范大学化学与环境科学学院,河南新乡453007 [2]河南省环境污染控制重点实验室黄淮水环境与污染防治省部共建教育部重点实验室,河南新乡453007

出　　处：《冶金分析》2008年第12期61-65,共5页Metallurgical Analysis

基　　金：河南省科技攻关计划重点项目(072102320007)

摘　　要：在硫酸介质中，pH4．1的邻苯二甲酸氢钾-氢氧化钠的缓冲溶液条件下，痕量铬（Ⅵ）与茜素紫作用能生成一种新的有色物质，十六烷基三甲基溴化胺（CTMAB）的加入可提高显色反应的灵敏度，且显色增强程度与铬（Ⅵ）浓度在一定范围内呈线性关系，据此建立了一种测定痕量铬（Ⅵ）的高灵敏光度分析新方法。该有色溶液的最大吸收波长为380nm，表观摩尔吸光系数ε为6．51×10^4L·mol^-1·cm^-1。系统研究了各种因素对显色反应的影响，在实验最佳条件下，测定铬（Ⅵ）的线性范围为4．0×10^-3～77．0μg／mL，方法的检出限为1．4×10^-4μg／mL。用于电镀液，铬钢中铬（Ⅵ）的测定，其结果与有证参考物质结果和原子吸收光谱法测定值对照，经统计学处理，无显著性差异，加标回收率在95％～100％之间。In the presence of H2SO4 and NaOH-KHC8 H4O4 buffer （pH 4.1）, trace chromium（Ⅵ）） reacted with alizarin violet to form a new color substance. When cetyltrimethylammonium bromide （CTMAB） was added, the sensitivity of the color reaction could be enhanced and the enhanced intensity was directly proportional to the concentration of chromium（Ⅵ）. According to this fact,a simple, rapid and highly sensitive spectrophotometry was established for the determination of trace chromium（Ⅵ）. The maximum absorption wavelength of the the new color substance was located at 380 nm with an apparent molar absorptivity of 6.51×10^4L·mol^-1·cm^-1. The effects of various factors on the color reaction were investigated systematically. Under the optimum experimental conditions, the linear range for chromium（Ⅵ） was 0. 004- 77.0μg/mL and the detection limit was 1.4 ×10^-4μg/mL. The method has been successfully applied to the determination of trace chromium（Ⅵ） in a electroplating solution and alloy steel samples with the recovery of 95%-100%. The results were satisfactorily compared with those determined by atomic absorption spectrometry and the certified value of standard sample.

关 键 词：铬(Ⅵ) 茜素紫 十六烷基三甲基溴化胺(CTMAB) 分光光度法 

分 类 号：O657.32[理学—分析化学]