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

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%.