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

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.