三酸微波消解-硝酸提取-电感耦合等离子体质谱法测定土壤中16种金属元素的含量

Determination of 16 Metal Elements in Soil by Inductively Coupled Plasma Mass Spectrometry with Triacid Microwave Digestion and Nitric Acid Extraction

提出了微波消解-电感耦合等离子体质谱法(ICP-MS)同时测定土壤中Be、V、Cr、Mn、Co、Ni、Cu、Zn、As、Mo、Cd、Sb、Tl、Pb、Th、U等16种金属元素含量的方法。取0.100 0 g土壤样品,在5 mL硝酸、1 mL盐酸和1 mL氢氟酸中微波消解,消解完成后,冷却至室温,于160℃赶酸至液体完全消失为止。残留物中加入2 mL硝酸,用去离子水定容至50 mL,摇匀后过0.45μm滤头,以ICP-MS测定,在线引入内标元素。结果表明:16种金属元素的质量浓度均在一定范围内与其质谱响应强度呈线性关系,检出限为0.008~0.41 mg·kg^(-1)。方法用于分析不同含量的土壤标准物质,测定结果与认定值基本一致,测定值的相对标准偏差(n=6)均小于5.0%。

A method for simultaneous determination of 16 metal elements including Be,V,Cr,Mn,Co,Ni,Cu,Zn,As,Mo,Cd,Sb,Tl,Pb,Th and U in soil by inductively coupled plasma mass spectrometry(ICP-MS)with microwave digestion was proposed.The soil sample(o.1oo 0 g)was digested by microwave in 5 mL of nitric acid,1 mL of hydrochloric acid and 1 mL of hydrofluoric acid.After digestion,the mixture was cooled to room temperature,and the acid was driven at 160℃until the liquid disappeared completely.2 mL of nitric acid was added into the residue,and its volume was made up to 50 mL with deionized water.After shaking well,the solution was passed through O.45μm filter member and determined by ICP-MS,and the internal standard element was introduced online.As shown by the results,linear relationships between the mass spectral intensity and the mass concentration of 16 metal elements were found in definite ranges,with detection limits of 0.008-0.41 mg·kg^(-1).This method was applied to analysis of soil reference materials with different contents,and the determined results were basically consistent with the certified values,with RSDs(n=6)of the determined values less than 5.0%.