材料期刊网

采用电感耦合等离子体原子发射光谱法( ICP-AES)测定含锌混合物中镉时,若不进行杂质分离,样品溶液中铅、锌等共存元素对镉的测定存在明显的正干扰。实验采用盐酸、硝酸消解样品,用碘化钾充分络合镉离子后,再用0．2 g强碱性阴离子交换纤维( SBAEF)选择性吸附经碘化钾络合后的镉离子,从而实现了镉离子与其他杂质元素的完全分离。将吸附的镉离子在pH 8的弱碱性环境中,用0．05 mol/L EDTA溶液在30℃时洗脱30 min,用ICP-AES测定洗脱出的镉,从而建立了强碱性阴离子交换纤维吸附-ICP-AES测定含锌物料中镉的方法。镉的质量浓度为0．2~1．0μg/mL时与其对应的发射强度呈线性,校准曲线的线性相关系数R2=0．9998；方法的检出限和测定下限分别为0．032×10-6(质量分数,下同)和0．13×10-6。按照实验方法测定4个含锌物料实际样品中镉,结果的相对标准偏差( RSD, n=11)为0．87%~1．6%,加标回收率为97%~102%。

During the determination of cadmium in mixture containing zinc by inductively coupled plasma atomic e-mission spectrometry ( ICP-AES) , the coexisting elements in sample solution such as lead and zinc had obviously positive interference with determination of cadmium if the impurities were not separated. The sample was digested with hydrochloric acid and nitric acid. After full complexation cadmium ions with potassium iodide solution, the complexed cadmium ions were selectively adsorbed with 0. 2 g of strong alkaline anion exchange fiber(SBAEF), re-alizing the complete separation of cadmium from other impurity elements. Then, in the weak alkaline medium at pH 8, the adsorbed cadmium ions were eluted with 0. 05 mol/L EDTA solution at 30℃ for 30 min. The eluted cadmi-um was determined by ICP-AES. Consequently, a determination method of cadmium in mixture containing zinc was established by ICP-AES after strong alkaline anion exchange fiber absorption. The mass concentration of cadmium in range of 0. 2-1. 0 μg/mL was linear to its corresponding emission intensity. The linear correlation coefficient of calibration curve was R2=0. 999 8. The detection limit and low limit of determination was 0. 032×10-6(mass frac-tion, similarly hereinafter) and 0. 13×10-6, respectively. The content of cadmium in four actual samples of mixture containing zinc was determined according to the experimental method. The relative standard deviations ( RSD, n=11 ) were between 0 . 87% and 1 . 6%. The recoveries were between 97% and 102%.