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

Key words: 
• Soil /
• microwave digestion /
• atomic fluorescence spectrometry /
• arsenic /
• mercury

Abstract: 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 μg·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 of1.2%-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.