AFS Determination of Mercury in Arsenic Ingot
A method of AFS for the determination of mercury in arsenic ingot was proposed.The sample was dissolved in mixed acid of HCl-HNO3(1+1),and Hg(Ⅱ)in the sample solution was extracted into n-butyl alcohol. Mercury(Ⅱ)in the organic phase was reduced to mercury vapor with 10g·L-1 potassium borohydride solution and determined by AFS.Linear relationship between values of fluorescence intensity and mass concentration of mercury was kept in the range of 0.15-80μg·L-1,with detection limit(3s/k)of 0.20μg·L-1.The proposed method was applied to the analysis of 2samples of arsenic ingots,giving values of RSD′s(n=6)less than 2%,and values of recovery found by standard addition method in the range of 96.3%-97.2%.