浮选光度法测定饮用水中亚硝酸根  

Determination of Nitrite in Drinking Water by Flotation Spectrophotometry

作　　者：祝优珍[1] 

机构地区：[1]上海应用技术学院化学工程系,上海200235

出　　处：《化学世界》2003年第9期468-470,490,共4页Chemical World

摘　　要：基于亚硝酸根在弱酸性的条件下重氮化反应 ,重氮化盐再与 N,N-二甲基苯胺进行偶合反应 ,生成黄色甲基橙 ,酸化后甲基橙变成红色 ,用十二烷基硫酸钠浮选富集 ,在正丁醇中收集浮选液 ,进行分光光度测定 ,从而求得亚硝酸根的含量。摩尔吸光系数ε为 9.7× 1 0 4L/ mol· cm(正丁醇为溶剂 ) ,亚硝酸根的浓度在 0 .0 4 1～ 0 .0 0 4 1μg/ m L与吸光度有良好的线性关系。A spectrophotometric method for determination of nitrite was introduced. In weak acidic solution, nitrite is first diazotized with p-aminobenzenesulfonic acid, and then the diazotate couples with N,N-dimethylaniline to form yellow methyl orange, whose color changes into red after acidification. Using ionic flotation technique the red methyl orange can be collected with butanol. Through determination of the absorbance value of the butanol solution the nitrite content is obtained. The molar absorbance coefficient is 9.7×10 4 L/mol·cm. A good liner relation is observed in the nitrite concentration range of 0.041~0.0041 μg/mL. The content of trace nitrite in pure water can be detected with this method.

关 键 词：甲基橙 亚硝酸根 吸光度 灵敏度 离子浮选 

分 类 号：O657.3[理学—分析化学]