显色剂meso-四(3-甲氧基-4-乙酰氧基苯基)卟啉的合成及其与镉(Ⅱ)的显色反应

Synthesis and application of meso-tetrakis(3-methyloxy-4-acetyloxyphenyl)porphyrin for spectrophotometric determination of trace cadmium(Ⅱ)

合成并表征了显色剂meso 四 (3 甲氧基 4 乙酰氧基苯基 )卟啉 ,并对其与镉 (Ⅱ )显色反应的条件及应用进行了研究。在SDS和 β CD存在下的pH 12 0的介质中 ,试剂与Cd(Ⅱ )形成 1∶1的配合物 ,其摩尔吸光系数ε43 9 0 =4 0 6× 10 5。镉含量在 0～ 0 112 μg/mL范围内符合比尔定律。提出了用巯基棉和KI EtOH (NH4) 2 SO4分离、富集样品中Cd(Ⅱ )的方法 。

A new chromogenic reagent,meso-tetrakis(3-methyloxy-4-acetyloxyphenyl)porphyrin,has been synthesized and characterized.Its reaction with cadmium(Ⅱ)forming a 1∶1 chelate complex at pH 12.0 has been used to determine trace amount of cadmium(Ⅱ)in the presence of SDS and β-CD.The maximum absorption peak of the complex occurred at 439.0nm with a molar absorptivity of 4.06×10~5L·mol^(-1)·cm^(-1).Beer′s Law was obeyed for cadmium(Ⅱ)in the range of 0～0.112μg/mL.Cadmium(Ⅱ)in samples was enriched and separated by extractions with mercapto cotton and KI-ethanol-(NH_4)_2SO_4.The recoveries were 95.8%～102.6%and relative standard deviations (1.0%～)3.5%.This proposed method was successfully applied to the determination of cadmium in water samples.