微波消解——双道原子荧光光谱法同时测定土壤中的砷和汞

采用硝酸—盐酸氢氟酸作为消解体系,以微波消解的方法处理土壤样品,双道原子荧光光谱法同时测定土壤样品中的砷和汞。设定最佳的样品前处理条件和仪器测定条件,通过国家标准参考物质和加标回收试验,对方法进行验证。结果表明,采用该方法,砷、汞的浓度范围分别在(0~50),(0~10)μg·L~(-1)时校正曲线呈线性,检出限分别为0.012,0.049μg·L~(-1),测定不同土壤标准物质,砷、汞测定结果均在标准值允差范围内,RSD范围分别为1.2%~3.5%和1.8%~4.2%,测定土壤中砷、汞的回收率范围分别为96%~112%和90%~117%。说明该方法稳定性好、精密度高、操作简便、成本低,适用于大量土壤样品砷、汞的同时测定。

Simultaneous Determination of Arsenic and Mercury in Soil by Microwave Digestion and Double Channel Atomic Fluorescence Spectrometry

Soil samples collected were treated by microwave digestion of nitric acid hydrochloric acid and hydrofluoric acid system to determine arsenic and mercury in soil simultaneously by using double channel atomic fluorescence spectrometry.The experimental conditions for treating and analyzing samples were optimized;the accuracy of the method was validated by determination of the certified reference materials,and spike recovery test.The results showed that the concentration curve was linear within the range of 0-50.0 μg · L-1 of arsenic and 0-10.0 pg · L-1 of mercury,the detection limits were 0.012 μg · L-1 and 0.049 μg · L-1 for arsenic and mercury,respectively.This method was used to determine arsenic and mercury in different soil reference materials,and the results fell within the allowable range.The relative standard deviations (RSD) were in the range of 1.2％-3.5％ and 1.8％-4.2％,and the recoveries of the soil samples collected were 96％-112％ and 90％-117％ for arsenic and mercury,respectively.This method was proved to be good in stability,high in precision,easy in operation and low in cost,and can be applied to determine arsenic and mercury simultaneously in a large number of soil samples.