离子交换分离石墨炉原子吸收光谱法测定高纯铟中痕量铜

高纯铟样品经盐酸溶解、以阳离子交换树脂分离出痕量铜后,用石墨炉原子吸收光谱法测定铜。研究了溶样方法、离子交换分离和测定铜的条件:用8mL浓盐酸将1g样品溶解;以0.6mol/L盐酸作为淋洗液进行离子交换,可把绝大部分铟基体及样品中痕量的银、砷、镉、硅分离除去,随后用2.0mol/L盐酸把铜洗出并收集之。铝、铁、镁、镍、铅、锡、铊、锌与小于10μg的铟不能与铜分离,但对测定无影响。当称样量为1g,进样量为50μL时,方法线性范围为1~4ng/mL,检出限为0.1ng/mL,测定下限为0.001μg/g,比行业标准方法 YS/T 230.1—2011的0.1μg/g低两个数量级。方法用于实际样品分析,结果与电感耦合等离子体质谱法(ICP-MS)相符,相对标准偏差(RSD,n=8)为1.7%~18.5%,加标回收率为94.8%~115.0%。

Determination of Trace Copper in High Purity Indium by Graphite Furnace Atomic Absorption Spectrometry after Ion-exchange Separation

After the high purity indium sample was dissolved by hydrochloric acid, trace copper was separated through cation-exchange resin and then was determined by graphite furnace atomic absorption spectrometry. Sample dissolution procedure, ion-exchange separation and determination condition for trace copper were investigated. The optimum conditions were found as following： 1 g indium sample was dissolved with 8 mL hydrochloric acid and the solution went through ion-exchange separation with 0.6 mol/L hydrochloric acid as leacheate. The trace silver, arsenic, cadmium, silicon in the sample and most of indium matrix could be separated and removed. Then, copper was eluted with 2.0 mol/L hydrochloric acid and collected. Although trace aluminium, iron, lead, magnesium, nickel, tin, thallium, zinc and loss than 10 μg indium could not be separated from copper, they had no influence on the determination of trace copper. When lg sample was weighted and 50 μL sample was injected, the linear range of this method was 1-4 ng/mL, the detection limit was 0. lng/mL, and the quantification limit was0. 001 μg/g which is two order of magnitude lower than 0.1 μg/g obtained by industry standard method YS/T230.1--2011. The proposed method was applied to analyze the actual sample, and the results were consistent with those obtained by inductively coupled plasma mass spectrometery （ICP-MS）. The relative standard deviations （RSD,n=8）were 1.7%-18.5%, and the recoveries were 94.8%-115.0%.