偶氮类显色剂的合成及其在口蘑微量铜测定中的应用

苏逸菲; 汤梦怡; 徐善东; 李强

doi:10.13386/j.issn1002-0306.2019.17.038

偶氮类显色剂的合成及其在口蘑微量铜测定中的应用

Synthesis of Azo-based Chromogenic Reagent and Its Application in Determination of Micro Copper in Tricholoma

摘要

摘要: 本文合成了偶氮类试剂3,5-二甲酸-4'-羟基偶氮苯,并研究了其与铜(Ⅱ)的显色反应。应用分光光度计测定了3,5-二甲酸-4'-羟基偶氮苯的用量、四硼酸钠缓冲溶液用量对生成配合物的影响,建立了一种测定口蘑中微量铜的新方法。结果表明:铜(Ⅱ)的质量浓度在0~2.5 μg·mL^-1内遵从比尔定律,其回归方程为Y=0.1696x+0.0237,R²=0.9921,摩尔吸光系数为4.3×10⁴ L·mol^-1·cm^-1,铜(Ⅱ)与3,5-二甲酸-4'-羟基偶氮苯形成1:1的配合物。加标回收率为97.0%~101.3%,RSD为0.93%~1.50%。本实验采用新的紫外分光光度法检测铜离子,操作简单、选择性好,用于口蘑中铜的测定,结果为(5.95±0.49)mg/100 g,与ICP光谱仪测得量为(5.89±0.09)mg·100 g^-1几乎一致。

Abstract: The azo-based chromogenic reagent 3,5-dicarboxylic acid-4'-hydroxyazobenzene was synthesized and its color reaction with copper(II)was also investigated. The amount of 3,5-dicarboxylic acid-4'-hydroxyazobenzene and the effect of sodium tetraborate buffer solution on the formation of complexes were determined by spectrophotometer. A new measured method for the micro copper(II)in tricholoma was established.The results showed that the mass concentration of copper(II)obeyed Bill's law in the range of 0~2.5 μg·mL^-1. The regression equation was Y=0.1696x+0.0237,R²=0.9921,and the molar absorptivity was 4.3×10⁴ L·mol^-1·cm^-1. Copper(II)complexes with 3,5-dicarboxylic acid-4'-hydroxyazobenzene formed a 1:1 complex. The recovery of standard addition was 97.0%~101.3% and RSD was 0.93%~1.50%. A new ultraviolet spectrophotometric method for the determination of copper ion in Tricholoma was developed. The method was simple and selective. The result was(5.95±0.49) mg·100 g^-1,which was almost the same as that measured by ICP spectrometer(5.89±0.09) mg·100 g^-1.