电感耦合等离子体质谱法测定矿物渣中微量铀和钍

ICP-MS Determination of Micro-amounts of Uranium and Thorium in Mineral Slags

采用改进的微波消解程序处理矿物渣样品,用185Re作为内标同位素,以在线内标加入法补偿样品的基体干扰,提出了测定矿物渣中微量铀和钍的电感耦合等离子体质谱法。铀和钍的方法检出限分别为0.017,0.021 ng.g-1;铀和钍的平均加标回收率(n=6)分别为99.0%,101.3%;相对标准偏差(n=6)分别为4.02%和3.54%。两种标准物质中铀和钍的测定结果与标准值相符合。

A method of ICP-MS determination of micro-amounts of uranium and thorium in mineral slags, with the application of an improved program of microwave assisted sample digestion, using ^185 Re as istopic internal standard to compensate for matrix interference by on-line addition of internal standard, was proposed. Detection limits （3S） were found to be 0. 017 ng · g^-1 and 0. 021 ng · g^-1 for uranium and thorium respectively. Tests for recovery and precision were made by adding standard solutions of uranium and thorium to a slag sample and analyzed by the proposed method, giving values of average recovery 99. 0% and 101.3% for uranium and thorium, and values of RSD＇s （n= 6） 4. 02% and 3. 54% respectively. Two CRM＇s were analyzed by the proposed method, giving results in consistency with the certified values.