键合4-(2-吡啶偶氮)-间苯二酚螯合树脂分离富集-火焰原子吸收法测定蔬菜中痕量镉(Ⅱ)

本文合成了Amberlite XAD-4键合4-(2-吡啶偶氮)-间苯二酚螯合树脂,并考察了其对痕量镉(Ⅱ)的吸附性能。探讨了溶液pH、洗脱剂和干扰离子等对镉(Ⅱ)分离富集的影响。树脂吸附容量为4.7mg/g,吸附的镉(Ⅱ)用5mL 2mol/L HNO3乙醇溶液洗脱,火焰原子吸收法测定。在最佳实验条件下,回收率为94.4%～97.9%,相对标准偏差在1.7%～2.7%之间。方法可用于蔬菜中镉(Ⅱ)的测定。

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.