地质样品中痕量镓的磷酸三丁酯纤维棉富集及其在电感耦合等离子体原子发射光谱法测定中的应用

Enrichment of trace gallium in geological sample by tributyl phosphate cellucotton and its application in inductively coupled plasma atomic emission spectrometric determination

研究了在盐酸介质中磷酸三丁酯纤维棉吸附分离镓的最佳条件及共存离子对吸附过程的影响。结果表明,在HCl(1+1)介质中,磷酸三丁酯纤维棉可定量吸附地质样品试液中镓,且吸附的镓能被HCl(1+23)定量洗脱,洗脱下来的镓用电感耦合等离子体原子发射光谱法(ICP-AES)测定,样品中与镓共存的K+、Na+、Ca2+、Mg2+、Cu2+、Pb2+、Zn2+、Ni 2+、Al 3+不干扰测定,Fe3+经还原后因不被磷酸三丁酯纤维棉吸附也不干扰镓的测定。将富集方法与ICP-AES相结合测定了地质标准物质中镓,测定值与认定值相符。对一样品中镓独立测定11次得到相对标准偏差(RSD)为3.3%。

The optimal adsorption and separation conditions of gallium by tributyl phosphate cellu- cotton in hydrochloric acid medium as well as the effect of coexisting ions on adsorption process were studied. The results showed that, the gallium in geological sample solution could be quantitatively ad- sorbed by tributyl phosphate cellucotton in HCI （1＋1） medium, Moreover, the adsorbed gallium could be quantitatively eluted by HC1 （1＋23） and then determined by inductively coupled plasma a- tomic emission spectrometry （ICP-AES）. The coexisting K＋ , Na＋ , Ca2＋ , Mg2＋ , Cu2＋ , Pb2＋ Zn2＋ , Ni2＋ and Al（Ⅲ） in sample did not interfere in the determination. Fe3＋ would not be adsorbed by tributyl phosphate cellucotton after reduction, thus had no interference. This enrichment method was combined with ICP-AES for the determination of gallium in standard geological samples. The results were consistent with the certified values. The relative standard deviation （RSD, n=11） was 3.3 %.