三氯偶氮胂与稀土元素显色反应的研究(Ⅰ)——直接光度法测定水中痕量稀土  

Study on the Color Reaction of Trichloroarsenazo with Rare Earth (Ⅰ) --Direct Determination of Trace Rare Earth in Tap Water

作　　者：陈丹华[1] 蔡汝秀[1] 余席茂[1] 曾云鹗[1] Chen Danhua;Cai Ruxiu;Yu Ximao;Zeng Yun'e(Chemistry Jiepartment of Wuhan University,Wuhan)

机构地区：[1]武汉大学化学系

出　　处：《高等学校化学学报》1985年第5期397-402,共6页Chemical Journal of Chinese Universities

基　　金：中国科学院科学基金资助课题。

摘　　要：本文对新显色剂三氯偶氮胂与稀土元素的显色反应进行了研究.该试剂灵敏度高,选择性好.用直接光度法测定水中痕量稀土,取得了满意的结果.水中痕量稀土测试的研究,对于环保部门严格控制和监测饮用水的污染程度,具有重要意义.国外有人用中子活化法测定了水中痕量La、Sm、Eu、Dy^([1])但仪器价格昂贵,方法不易推广.The color reaction of trichloroarscnazo (TCA) (2-(2-arsonophcnylazo)-7-(2, 4,6-trichlorophcnylazo)-1,8-dihydroxy-3,6-disulfonaphthalcne) with rare earth has been studied in this paper.TCA was found to have high sensitivity to Cerium group rare earth ε = 1.079-1.308×10^(5) and to the amount of rare earths ε = 0.937-1.329×10^(5), big comparison degree (Δλ = 93-104nm), and good selectivity. Large amounts of Ca (10mg), Mg(8mg), Al (60mg) do not interfere with the determination. It is one of the best selective reagents for rare earths up to now. The absorption maximum of the complex is near 630nm, Beer’s Law is obeyed for 0-5μg RE_(x)O_(y)/25ml (5cm cell) and 0-60μg RE_(x)O_(y)/25ml (1cm cell) ranges. Tt was applied to determine the trace rare earths in tap water by direct spectrophotometric method, which was simple, exact and rapid. The results were satisfactory.

关 键 词：显色反应 稀土元素 新显色剂 中子活化法 痕量稀土 三氯偶氮胂 饮用水 

分 类 号：O65[理学—分析化学]