双硫腙螯合型树脂同时分离富集-火焰原子吸收光谱法测定痕量铅和镉

Simultaneous separation,concentration and determination of trace lead and cadmium with dithizonic chelating resin by flame atomic absorption spectrometry

以大孔聚苯乙烯树脂为母体,通过-N=N-,与双硫腙键合,合成了双硫腙螯合型树脂,并将其应用于痕量铅和镉的同时分离富集,实验了酸度、流速、共存离子干扰等因素对双硫腙螯合型树脂吸附和洗脱Pb和Cd的影响,建立了双硫腙螯合型树脂同时分离富集-火焰原子吸收光度法测定食品及环境样品中痕量Pb和Cd的方法。对Pb和Cd,方法的检出限分别为0.015和0.0013μg/mL,相对标准偏差(RSD)均优于3.0%。

A dithizonic chelating resin was synthesized by coupling macro-porous polystyrene resin functionalized with dithizone through - N =N-group, and was used to separate and concentrate trace lead and cadmium by column chromatography. The factors, which affected the adsorption and elution of lead and cadmium, such as acidity, flow rate and interference of co-existing ions were tested. A method for the simultaneous separation, concentration and de- termination of trace cadmium and lead with dithizonic chelating resin by flame atomic absorption spectrometry has been developed. The method has been applied to the simultaneous determination of trace lead and cadmium in food and en- vironmental samples with satisfactory results. The detection limit was 0. 015μg/mL for lead and 0. 0013 μg/mL for cadmium respectively, and the relative standard deviation （RSD） was less than 3.0% for lead or cadmium.