全自动石墨消解-电感耦合等离子体质谱法测定土壤中12种重金属元素的含量

Determination of 12 Heavy Metal Elements in Soil by Inductively Coupled Plasma Mass Spectrometry with Automatic Graphite Digestion

分取约0.1000 g处理后的土壤样品,用少量水润湿,以3 mL硝酸、3 mL氢氟酸和1 mL高氯酸为酸体系,采用全自动石墨炉消解仪于150℃消解样品2.0 h。消解完成后,赶酸,消解液和水冲洗液一起转移至50 mL容量瓶中,再用水定容,混匀,过0.45μm滤膜,滤液按照电感耦合等离子体质谱仪工作条件进行测定。结果表明:钒、铬、锰、钴、镍、铜、锌、砷、镉、铅、钼、锑等12种重金属元素的质量浓度均在200μg·L^(-1)以内与所对应的响应强度与内标响应强度比呈线性关系,检出限(3s)为0.008~0.250μg·g^(-1);对土壤标准样品GSS-13、GSS-19、GSS-23进行准确度和精密度试验,测定值均在认定值的不确定度范围内,并且测定值的相对标准偏差(n=6)均不大于4.0%;方法用于5个实际土壤样品分析,12种重金属元素测定值均未超过国家土壤环境质量二级标准。

An aliquot about 0.1000 g of treated soil sample was taken,and wetted with a small amount of water.Nitric acid(3 mL),hydrofluoric acid(3 mL)and perchloric acid(1 mL)were used as acid system,and the sample were digested at 150℃for 2.0 h by a automatic graphite furnace digester.After the digestion was completed,the acid was removed,and the digestion solution and water rinsing solution were transferred into a 50 mL-volumetric bottle,and then diluted with water to volume.After mixing well,the above solution was filtered through a 0.45μm filter membrane,and the filtrate was determined according to the working conditions of the inductively coupled plasma mass spectrometer.It was shown that linear relationships between the values of mass concentrations of 12 heavy metal elements including vanadium,chromium,manganese,cobalt,nickel,copper,zinc,arsenic,cadmium,lead,molybdenum and antimony and response intensity ratios of their to internal standards were within 200μg·L^(-1),with detection limits(3s)in the range of 0.008-0.250μg·g^(-1).Tests for accuracy and precision on the soil standard samples GSS-13,GSS-19 and GSS-23 were carried out,and the determined values were within the uncertainty ranges of the confirmed values,and RSDs(n=6)of the determined values were less than 4.0%.The method was used to analyze 5 actual soil samples,and the determined values of 12 heavy metal elements did not exceed the national secondary standard of soil environmental quality.