Separation and Preconcentration of Trace Cadmium from Vegetables with 4-(2-Pyridylazo)-resorcinol Immobilized on Amberlite XAD-4 Prior to Determination by Flame Atomic Absorption Spectrometry

A new method for the determination of trace Cd(Ⅱ) based on Amberlite XAD-4 bonded with 4-(2-pyridylazo)resorcinol adsorption with flame atomic absorption spectrometry(FAAS) was proposed.In this process,the effects of pH,elution agent,interfering ions and other experimental conditions on separation and preconcentration of trace Cd(Ⅱ) were studied.Adsorption capacities of the resin was 4.7 mg/g.The adsorbed Cd(Ⅱ) on the resin could be completely eluted with 5 mL of 2 mol/L HNO3 ethanol solution and then determined by FAAS.Under the optimum conditions,the recoveries were in the range from 94.4% to 97.9%,and relative standard deviations were between 1.7% and 2.7%.The proposed method was applied for the determination of trace Cd(Ⅱ) in vegetable with satisfactory results.