高等学校化学学报

高等学校化学学报 ›› 1986, Vol. 7 ›› Issue (7): 585.

• 研究论文 • 上一篇    下一篇

双波长分光光度法测定大米中的痕量镉—Cd(Ⅱ)-Cadion 2B-Tween 40体系

浦炳寅, 魏丹毅   

  1. 宁波师范学院化学系
  • 收稿日期:1985-05-08 出版日期:1986-07-24 发布日期:1986-07-24

The Determination of Trace Amounts of Cadmium in Rice Samples by Dual-Wave Length Spectrophotometry—Cd(Ⅱ)-Cadion 2

Pu Binying, Wei Danyi   

  1. Department of Chemistry, Ningbo Normal College, Ningbo
  • Received:1985-05-08 Online:1986-07-24 Published:1986-07-24

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摘要： 本文研究了Cd(Ⅱ)-Cadion 2B-Tween 40显色反应的最佳条件。测定了不同Tween 40浓度下Cadion 2B的酸离解常数和表面张力。实验证明,Tween 40 促进了Cadion 2B的酸离解作用。过量试剂的消耗时Cd(Ⅱ)有强烈的响应,用ΔA510-605nm测定Cd(Ⅱ),其表观摩尔吸光系数ε510-605nm=2.60×105。Cd(Ⅱ)在0—16μg/25ml范围内符合比尔定律。利用TEA、IDA、Cit混合掩蔽剂,并采用标准加入法测定了大米中的痕量镉。

Abstract: The Optimal conditions of the Cd(Ⅰ)-Cadion 2B-Twecn 40 system have been studied.In the NaOHalkaline medium,,a red Cd(Ⅱ)-Cadion 2B-Tween 40 complex forms with ε510nm=9.80×104.The Ka of Cadion 2Band Surface tension in the system were estimated.It was proved that Ka was increased and the reagent species with absorption maximum at 605nm formed.Using the dual-wave length method at 510-605nm the apparent molar absorptivity for cadmium measured is 2.60×105.The molar ratio of cadmium with Cadion 2B is estimated 1: 3 as by the molar ratio method and continueous variation method.The Beer's law is obeyed in 0-16μg Cd/25ml.Using the proposed method with TEA,IDA,CITmasking mixture,the Cd content in rice samples was determined with satisfactory results.

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