泡沫塑料吸附分离富集-电感耦合等离子体质谱法测定稀土矿石中的镓

摘要

Gallium in rare earth ore is commonly determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS),but high content of rare earth will result in significant mass spectrum interferences. In this study,Ga in sample solution was absorbed by polyurethane foam in 6 mol/ L HCl. Gallium adsorbed on the foam could be quantitatively eluted with 0. 5 mol/ L NH4 Cl solution in a heating water bath for 30min. The adsorption-eluted efficiency is higher than 99% . Most of the matrix elements could be separated from Ga by polyurethane foam so the mass spectrum interferences were reduced effectively. The detection limit was 0. 022 μg / g. The accuracy of the developed method was evaluated by analyzing Ga in soil and stream sediment standard reference materials. The proposed method was successfully applied to gallium determination in geological samples and rare earth ores. The recoveries are 94. 1% - 100. 6% and the precision is 2. 2% - 4%(RSD,n = 12).%采用电感耦合等离子体质谱法(ICP - MS)测定稀土矿石中的镓,高含量的稀土元素会造成严重的质谱干扰.本文采用聚氨酯泡沫塑料在 6 mol/ L 盐酸介质中吸附样品溶液中的镓后,以 0. 5 mol/ L 氯化铵水浴加热解脱 30 min,镓的吸附 - 解脱效率超过 99% ,稀土元素等干扰物质基本不进入解脱液中,即在富集镓的同时实现了镓与基体元素的高效分离,降低了质谱干扰.本方法检出限低(0. 022 μg / g),经土壤及水系沉积物标准物质验证,镓的测定值与标准值吻合(绝对偏差为 0. 38% ~ 4. 70% ),实际稀土矿石样品的加标回收率为 94. 1% ~ 100. 6% ,精密度(RSD)低于 4%(n = 12),可应用于分析一般地质样品以及稀土矿石中的镓.