Simultaneous Determination of Arsenic and Mercury in Aweto by HG-AFS with Microwave Assisted Sample Digestion

Double channel AFS with hydride generation was applied to the simultaneous determinations of arsenic and mercury in aweto.The working conditions of instrument were described in detail,and influential factors,including the sample digestion conditions,amount of potassium borohydride added,concentration and kinds of acids used were studied and optimized.Linear relationships between the fluorescence intensity and mass concentration of As and Hg found were in the ranges within 10 μg·L-1 and 1 μg·L-1,with detection limits (3S/N) of 0.2 μg·kg-1 and 0.02 μg·kg-1,respectively.Values of RSD′s (n=10) of the method found were less than 4.0%.The proposed method was applied to the analysis of samples of aweto.Using these samples as matrixes,tests for recovery were made by standard addition method,values of recovery found were in the range of 93.8%-104.4%for arsenic,and 94.0%-98.0% for mercury.