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化学学报
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化学学报 ›› 1964, Vol. 30 ›› Issue (2): 101-107.    下一篇

论文

微量钒的催化测定

田笠卿, 张文彬   

  1. 南京大学化学系
  • 投稿日期:1962-12-25 发布日期:2013-06-03

A STUDY OF THE CATALYTIC DETERMINATION OF MICRO AMOUNTS OF VANADIUM

TIEN LI-CHING, CHANG WEN-BING   

  1. Department of Chemistry, Nanking University
  • Received:1962-12-25 Published:2013-06-03

PDF

532

被引次数

4

本文报告利用钒对氯酸钾氧化联苯胺反应的催化作用,比色测定微量钒的方法.在微酸性溶液中,氯酸钾与联苯胺反应速度极小,但钒能催化此反应,若同时有8-羟基喹啉,则增强催化作用.反应生成的红色产物在510毫微米处有最大吸收.当溶液的pH保持2.5-3.0时,催化反应速度随温度而升高,在沸腾溶液中的催化速度比10°时约大四千倍.适当延长或缩短加热时间,可使所生成的有色溶液适于分光光度测定.当钒浓度在0.0001-10微克/毫升范围时,皆符合Beer定律.且灵敏度较高.钒浓度为0.05微克/毫升时,平均误差为±2%.在每毫升欲测溶液中,钾、钠、氯离子、硝酸根达5毫克;铵、钙(Ⅱ)、镁(Ⅱ)、溴离子达1毫克;铀(Ⅵ)、硼(Ⅲ)、氟离子达0.2毫克;锌(Ⅱ)、镉(Ⅱ)、镍(Ⅱ)、铅(Ⅱ)、锰(Ⅱ)达0.1毫克;钴(Ⅱ)、铝(Ⅲ)达0.05毫克;铜(Ⅱ)达0.02毫克皆无干扰.银(Ⅰ)、钼(Ⅳ)达0.02毫克;钨(Ⅵ)达0.01毫克稍干扰.铁(Ⅲ)、铬(Ⅲ,Ⅵ)、硫酸根等干扰.

The catalytic action of vanadium on the reaction between benzidine and potassium chlorate has been studied and therefrom a sensitive and convenient method fox the detexmination of traces of vanadium has been proposed.The reaction rate between benzidine and potassium chlorate is very slow.If micro amounts of vanadium and small amounts of oxine are added to the test solution at pH 2.5-3.0,and heat for some time at 100℃ then the vanadium shows a strong catalytic action on the above reaction.