meso-四(4-羟基-3-甲氧基苯基)卟啉光度法测定汞(Ⅱ)

Determination of mercury (Ⅱ) by spectrophotometry with meso-tetrakis(4-hydroxyl-3-methoxylphenyl)porphyrin

建立了一种以meso-四（4-羟基-3-甲氧基苯基）卟啉ET（4-H-3-MOP）P]为显色剂测定汞（Ⅱ）的分光光度法。在Triton X-l00存在下，于pH9．60Na2B4O7-NaOH缓冲液中，在室温条件下试剂与汞（Ⅱ）显色反应5min，可生成络合比为2：l的浅棕黄色配合物。配合物的最大吸收峰位于440nm，表观摩尔吸光系数为1．34×10^5L·mol^1·cm^1，汞（Ⅱ）的质量浓度在0～0．6μg／mL之间符合比尔定律，方法检出限为9．2×10^3μg／mL。在显色体系中加入三乙醇胺一酒石酸钾钠一氟化钠混合掩蔽剂后，用方法测定了化工厂和实验室废水中汞（Ⅱ），并与冷原子吸收法的结果一致，相对标准偏差不大于2．6％，加标回收率在99％～102％之间。

A new spectrophotometry was established to determine Hg (Ⅱ) by using meso-tetrakis(4-hydroxyl-3-methoxylphenyl)porphyrin(T(4-H-3-MOP)P)as chromogenic agent.In the presence of Triton X-100,T(4-H-3-MOP)P can react with Hg (Ⅱ)in Na2B4O7-NaOH buffer solution at pH 9.60 at room temperature,forming a light brown-yellow stable coordination complex with a molar ratio of 2∶1.The maximum absorption peak of the complex was located at 440 nm.The apparent molar absorptivity was 1.34×105L·mol-1·cm-1.Beer's law was obeyed within mass concentration of 0-0.6μg/mL for Hg (Ⅱ)and the detection limit was 9.2×10-3μg/mL.With mixed masking reagent of triethanolamine-sodium tartrate-sodium fluoride in the chromogenic system,Hg (Ⅱ)in chemical industrial and laboratorial waste water was determined by proposed method,whose results were consistent with those of cold vapour atomic absorption spectrometry.The relative standard deviation(RSD)was less than 2.6%,and the standard addition recovery was 99%-102%.