The distribution coefficients (Kd) and adsorption capacity of Pb2+ , Cd2+ and Na+ on Chelex-100, a chelating resin in media of different pH values were studied. It was found that in a medium of pH 1 — 8, the Kd of Na+ was less than 3, while the Kd of Pb2+ and Cd2+ were more than 104 , hence, Pb2+ and Cd2+ were adsorbed strongly on the resin, while Na+ was not adsorbed. And Pb2+ and Cd2+ were completely eluted from resin with 0. 16 mol· L-1 HNO3 as eluent. Based on these facts, a method of AAS determination of cadmium and lead in high-salt food was proposed. Sample of high-salt food was analyzed by the proposed method, giving values of recovery in the range of 93. 1% —102%, and values of RSD's (n = 5) in the range of 0. 5% —3. 4%.%对铅、镉和钠在Chelex-100树脂上于不同pH值的介质中的分配系数(Kd)和吸附容量进行了研究.结果表明:在pH 1～8的介质中Na+的Kd＜3,即在Chelex-100树脂上无吸附；在pH＞4的介质中,Pb2+和Cd2+的Kd＞104,即强吸附于Chelex-100树脂上；而用0.16 mol·L-1硝酸溶液可将吸附于树脂上的Pb2+和Cd2+完全洗脱下来.在此基础上提出了一种Chelex-100树脂分离原子吸收光谱法测定高盐食品中重金属元素含量的方法.方法用于高盐食品分析,加标回收率在93.1％～102％之间,测定值的相对标准偏差(n=5)在0.5％～3.4％之间.
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