微波消解-电感耦合等离子体质谱法测定土壤中稀土元素条件优化

Optimization of microwave digestion inductively coupled plasma mass spectrometry for determination of rare earth elements in soil

稀土元素因其用途广泛,已经得到了越来越多的关注,被应用于各个行业。研究表明,稀土元素对作物的光合作用、产量、抗逆、品质、发育和养分吸收等具有重要作用。作物中的稀土元素主要来自对土壤中稀土元素的吸收,因此,有效分解并快速测定土壤中的稀土元素,可以合理指导稀土元素的施用,对作物的生长和土壤的营养状况具有重要作用。本文比较了敞口酸溶、密闭消解、微波消解和碱熔等4种消解样品前处理方法,最终确定采用微波消解-电感耦合等离子体质谱法(ICP-MS)快速测定土壤中的稀土元素,并通过优化微波消解的条件,选择合适的试剂用量、消解温度、消解时间,对方法的检出限、精密度、准确度、回收率进行了实验,结果显示其测定均值与标准值基本吻合,相对误差(RE)绝对值为0.16%~3.39%,精密度为0.27%~5.09%,均小于10%,加标回收率为93.1%~106.0%。该方法准确度高、稳定性好,可以有效地应用于土壤中稀土元素的分析测定。

The widespread use of rare earth elements has attracted increasing attention.Studies have shown that rare earth elements play an important role in such aspects of the crop as photosynthesis,yield,stress resistance,quality,development and nutrient absorption of crops.Therefore,effective decomposition and rapid determination of rare earth elements in soil can reasonably guide the application of rare earth elements and play an important role in crop growth and soil nutrition.Methods of digestion such as acid digestion,closed acid digestion,microwave acid digestion and alkali melting were studied in this experiment.Microwave digestion-ICP-MS method was adopted which can rapidly and effectively determine rare earth elements in soil.The experiment optimized the digestion conditions including microwave digestion program,dosage of chemical reagent,digestion temperature,and digestion time.The detection limit,precision,accuracy and recovery were tested,which shows the method is effective and feasible.The value was 0.16%~3.39%,0.27%~5.09%and 93.1%~106.0%.