测定了铁、铅、砷、镍、钴在CL-TBP萃淋树脂于不同酸度的盐酸和硝酸介质中的分配系数(Kd)值.试验结果表明:在5~9 mol·L-1盐酸介质中铁(Ⅲ)的Kd>104,即强吸附于CL-TBP萃淋树脂柱,而铅、砷、镍和钴在CL-TBP萃淋树脂柱的Kd≤12,即不吸附剂于树脂;在≤2 mol·L-1的硝酸介质中,铁(Ⅲ)的Kd<12,即不吸附于树脂.用0.5 mol·L-1硝酸作为淋洗液可洗下吸附于柱的铁(Ⅲ).并测定了CL-TBP萃淋树脂的吸附容量.由此建立了萃淋树脂分离、电感耦合等离子体原子发射光谱法测定高纯氧化铁中铅、砷、镍和钴的方法.

Distribution coefficients (Kd) of Fe(Ⅲ),Pb(Ⅱ),As(Ⅲ,Ⅴ),Ni(Ⅱ) and Co(Ⅱ) on the extraction resin (CL-TBP) in hydrochloric and nitric acid medium of different acidities were determined.As shown by experimental data,① value of Kd of Fe(Ⅲ) was found to be larger than 104 in 5-9 mol·L-1 HCl medium,while values of Kd of Pb(Ⅱ),As(Ⅲ,Ⅴ),Ni(Ⅱ) and Co(Ⅱ) were equal to or smaller than 12,indicating that under this condition,Fe(Ⅲ) was strongly adsorbed on the resin and Pb(Ⅱ),As(Ⅲ,Ⅴ),Ni(Ⅱ) and Co(Ⅱ) were not adsorbed;and ② value of Kd of Fe(Ⅲ) were found to be less than 12 in HNO3 medium with its acidity less than 2 mol·L-1;based on this fact,0.5 mol·L-1 HNO3 was selected as an eluent to elute Fe(Ⅲ) from the resin.Absorption capacity of the CL-TBP resin was also determined.On the base of these phenomena,a method for the ICP-AES determination of trace amounts of Pb(Ⅱ),As(Ⅴ),Ni(Ⅱ) and Co(Ⅱ) in high-purity iron oxide after column-chromatographic separation on CL-TBP resin was proposed.