HG-AFS Determination of Arsenic in Soil

HG-AFS was applied to the determination of arsenic in soil.Sample was digested with mixed solution of conc.HNO3-conc.HCl (1+1) heated in boiling water for 1 h.Influential factors,including negative high-voltage,lamp current,the flow-rates of carrier gas and shielding gas,amount of potassium borohydride added,concentration and kinds of acids,and interferences of coexisting ions were studied and optimized.Linear relationship between the fluorescence intensity and mass concentration of As was obtained in the range within 100 μg·L-1,with detection limit (3s/b) of 0.6 μg·L-1.Value of RSD (n=6) of the method found was less than 5%.The proposed method was applied to the analysis of standard material (ESS-1) and soil samples,and values of recovery found were ranged from 93% to 105%.