土壤中重金属的测定,前处理过程中消解效果是关键,分析过程电感耦合等离子体质谱法(ICP-MS)分析模式、内标及其浓度的选择很重要。实验分别利用三酸-微波消解和四酸-石墨消解对7种土壤标样进行消解,ICP-MS对其中的12种金属元素进行测定,通过测定结果对比石墨消解不同消解温度条件下的消解效果差异,比较不同浓度内标对土壤标样定量结果的影响;考察碰撞模式和干扰校正方程测定土壤中镉的结果差异;利用离子色谱评估两种消解方式消解后的酸根残留。结果显示,一定条件下两种消解方法对随机选取的大多数土壤标样,大多数元素均有较好的效果,7种土壤标样的12种元素,微波消解约87%的测定结果在参考值范围内,石墨消解约95%的测定结果在参考值范围内;离子色谱结果显示石墨消解的酸根残留更少。

For the determination of heavy metals in the soil, the digestion effect of the pretreatment process is the key. The selection of the inductively coupled plasma mass spectrometry(ICP-MS) analysis mode, internal standard and its concentration during the analysis process is very important. The experiment uses three kinds of acid-microwave digestion and four kinds of acid-graphite digestion to digest 7 kinds of soil standard samples.ICP-MS measures 12 kinds of metal elements among them, and compares the different digestion temperature conditions of graphite digestion through the measurement results. The difference in the digestion effect under the following conditions, compared the effects of different concentrations of internal standards on the quantitative results of the soil standard; the difference in the results of the collision mode and the interference correction equation in the determination of cadmium in the soil was investigated; the acid radicals after the two digestion methods were evaluated by ion chromatography residue. The results show that under certain conditions, the two digestion methods have good effects on most of the randomly selected soil standard samples and most elements. For the 12 elements of 7 soil standard samples, about 87% of the determination results of microwave digestion are in the reference within the value range, about 95% of the determination results of graphite digestion are within the reference value range; the ion chromatography results show that there are fewer acid radicals remaining in the graphite digestion.