电感耦合等离子体质谱法测定白云鄂博矿区土壤及植物中稀土总量

Determination of Total Rare Earth in Soil and Plants in Bayan Obo Mining Area by Inductively Coupled Plasma Mass Spectrometry

利用碱熔融,硝酸和高氯酸破坏滤纸和溶解沉淀处理土壤样品,微波消解处理植物样品,采用ICPMS法测定土壤及植物中稀土含量。通过实验选择最佳测定同位素,对仪器工作条件进行优化,确定功率为1100 W,载气流量为0.80 L/min。讨论了测定条件对结果的影响,确定测定介质为1%盐酸,内标元素为Cs,研究土壤的最佳溶解条件,并用正交实验确定了植物的溶解条件。方法测定下限为:土壤0.030 ng/m L^0.30 ng/m L,植物0.004 ng/m L^0.012 ng/m L,采用实际样品进行测定,回收率均在95%~105%之间,RSD<4%。

The soil samples were decomposed by alkali melt, the filter paper was damaged and the precipitate was dis- solved by nitric acid and perchlorie acid,and the plant samples decomposed by microwave digestion. The total content of rare earth in the soil and the plants was determined by inductively coupled plasma mass spectrometry. The best determination iso- tope was selected by experiment, the working conditions of instrument were optimized, and the power and nebulizer gas flow were determined as 1100 W and 0.80 L/min, respectively. The influence of measurement conditions on the results was investi- gated. Determination medium was determined as 1% hydrochloric acid, and the internal standard elements is Cs. Optimal disso- lution conditions of the soil was determined . Orthogonal experiment was conducted to determine the dissolution conditions of the plants. The detection limit of the method is 0. 030 ng/mL - 0.30 ng/mL for soil, and 0. 004 ng/mL - 0. 012 ng / mL for plant;Recoveries （n =20） were 95% - 105% ;RSDs for the determination of actual samples were less than 4% （n =20）.