微波消解-电感耦合等离子体质谱法测定土壤中10种重金属元素

Determination of ten heavy metals in soil by microwave digestion-inductively coupled plasma-mass spectrometry

利用硝酸、盐酸、氢氟酸混合液和微波消解仪密闭消解样品,建立了一种微波消解-电感耦合等离子体质谱(ICP-MS)法同时测定土壤中铜、铅、锌、锰、钒、铬、镉、镍、锡、铊10种重金属的分析方法。取0.1000 g土壤样品于消解罐中,采用4 mL硝酸+1 mL盐酸+1 mL氢氟酸消解体系按照设定程序进行微波消解,冷却,定容后利用电感耦合等离子体质谱法进行。结果表明,以铑元素作为内标,10种重金属元素在一定的质量浓度范围内与其信号强度呈线性关系,线性相关系数均不小于0.9998,检出限为0.010~0.92 mg/kg。对3种标准物质进行测定,测定值的相对标准偏差为2.89%~7.72%(n=10),相对偏差为-5.95%~4.11%。该方法分析流程简单,工作效率高,检出限低,适合大批量土壤样品的多元素同时分析。

The soil sample was digested with mixture nitric acid,hydrochloric acid,and hydrofluoric acid in microwave digestion instrument,ten heavy metals such as opper,lead,zinc,manganese,vanadium,chromium,cadmium,nickel,tin and thallium in which were determined simultaneously by inductively coupled plasma-mass spectrometry(ICPMS).0.1000 g soil samples were taken in the digestion tank,and 4 mL nitric acid+1 mL hydrochloric acid+1 mL hydrofluoric acid were used as digestion system to microwave digest soil samples according to the set procedure.After cooling and volumetric fixing,inductively coupled plasma mass spectrometry was exploited for determination.The results indicated that utilizing Rh as the internal standard,there was a linear relationship between the ten heavy metal elements contents and their signal intensity within a certain mass concentration range with the corelation coefficients all not less than 0.9998.The detection limits were 0.010 to 0.92 mg/kg.Three reference materials were determined by this method,and the relative standard deviations were 2.89%to 7.72%(n=10),and the relative errors were-5.95%to 4.11%.This method has the advantages of simple process,high efficiency and low detection limit,which is suitable for the simultaneous analysis of multiple elements in large quantities of soil samples.