硅藻土负载TODGA分离-电感耦合等离子体质谱法测定氧化铈中氧化钆、氧化铽

TODGA Loading on Diatomite Separation-ICP-MS Determination of Gadolinium Oxide and Terbium Oxide in Cerium Oxide

建立了硅藻土负载N,N,N′,N′-四辛基-3-氧戊二酰胺(TODGA)分离柱分离,电感耦合等离子体质谱法(ICP-MS)测定氧化铈中氧化钆、氧化铽含量的方法。试样用50%(体积分数)硝酸溶液和30%过氧化氢溶解,取含氧化铈50 mg的样品溶液导入自制的硅藻土负载TODGA的分离柱(连接一个蠕动泵,用于控制流量),用pH 1.5的硝酸溶液以2.0 mL·min^(-1)流量淋洗分离柱,直至淋洗液中铈的质量浓度小于1000μg·L^(-1)。用60 mL pH 0.92的盐酸溶液以2.0 mL·min^(-1)流量反洗待测元素钆和铽,弃去前20 mL反洗液,收集后40 mL反洗液并用水稀释至50 mL。在线加入10μg·L^(-1)铯内标溶液,用ICP-MS分析样品溶液中目标物的含量。结果显示,氧化钆、氧化铽的质量浓度均在50.00μg·L^(-1)以内与其对应的待测元素与内标元素强度比值呈线性关系,检出限(3s)分别为0.102,0.049μg·g^(-1)。方法用于实际样品分析,氧化钆和氧化铽的测定值分别为0.73,0.68μg·g^(-1),测定值的相对标准偏差(n=11)为4.8%和5.2%,加标回收率分别为101%和99.0%。

A method for the determination of gadolinium oxide and terbium oxide in cerium oxide by inductively coupled plasma mass spectrometry(ICP-MS) after separation with TODGA loading on diatomite column was established. The sample was dissolved by 50%(volume fraction) nitric acid solution and 30% hydrogen peroxide solution, and the sample solution containing 50 mg cerium oxide was introduced into the homemade TODGA loading on diatomite separation column, which was connected with a peristaltic pump to control the flow rate. The column was rinsed with pH 1.5 nitric acid solution at a flow rate of 2.0 mL·min^(-1) until the mass concentration of cerium in the rinsing solution was less than 1 000 μg·L^(-1). 60 mL of pH 0.92 hydrochloric acid solution was used to backwash gadolinium and terbium at a flow rate of 2.0 mL·min^(-1), the first 20 mL backwashing solution was discarded, and the subsequent 40 mL backwashing solution was collected and its volume was made up to 50 mL with water. 10 μg·L^(-1) cesium internal standard solution was added online, and the contents of analytes in the sample solution were determined by ICP-MS. The results showed that linearity relationships between mass concentrations of gadolinium oxide and terbium oxide and the intensity ratios of analytes to internal standard element were kept within 50.00 μg·L^(-1), with detection limits(3s) of 0.102, 0.049 μg·g^(-1). The proposed method was applied to the analysis of actual samples, giving determined values of gadolinium oxide and terbium oxide of 0.73, 0.68 μg·g^(-1), RSDs(n=11) of the determined values were 4.8% and 5.2%, and values of recovery were 101% and 99.0%.