镁试剂Ⅰ褪色光度法测定铬Ⅵ  

Decoloration spectrophotometric determination of chromiumⅥ with magneson Ⅰ

作　　者：葛洪玉[1] 贾海红[1] 马卫兴[1] 

机构地区：[1]淮海工学院化学工程系,江苏连云港222005

出　　处：《冶金分析》2005年第6期70-72,共3页Metallurgical Analysis

基　　金：淮海工学院自然科学研究基金资助项目(Z2004026);淮海工学院学科基金资助项目(XK200310);江苏省高校自然科学研究计划资助项目(05KJB15003)

摘　　要：在硫酸介质中,铬(Ⅵ)能氧化镁试剂Ⅰ使之褪色,且褪色程度与铬(Ⅵ)的量线性相关,据此建立了光度法测定铬(Ⅵ)的新方法.在沸水浴加热条件下反应产物最大吸收峰在420 nm处,表观摩尔吸光系数为1.02×104.在25 mL溶液中,铬(Ⅵ)量在0～40μg范围内服从比尔定律.方法用于钢样和水样中铬的测定,结果与认定值相吻合,RSD小于2.1%.In the medium of sulphuric acid, the color of magneson Ⅰ could be faded by oxidation of chromium, and the degree of color fading was proportional to the concentration of chromium（Ⅵ）, and a new spectrophotometric method for the determination of chromium（Ⅵ） was developed. The maximum absorption of color solution was at 420 nm with a molar absorptivity of 1.02×10^4 L·mol^-1·cm^-1. Beer＇s law was obeyed in the range of 0～40 μg/25 mL for chromium（Ⅵ）. The proposed method has been applied to the determination of chromium in steel samples and water samples, and the results are agreement with certified values with RSD≤2.1%.

关 键 词：镁试剂Ⅰ 铬 褪色光度法 钢样 水样 

分 类 号：O657.3[理学—分析化学] O614.61[理学—化学]