Simultaneous Determination of As and Hg in Water by Hydride Generation-Atomic Fluorescence Spectrometry

HG-AFS was applied to the simultaneous determinations of arsenic and mercury in water.The working condition of instrument,including negative high-voltage,lamp current,the rates of carrier and shield gases,was described in detail.Influential factors,including the concentration and kinds of acids,amount of potassium borohydride added,concentration of mixed solution of thiourea and ascorbic acid,and interferences of the coexisting ions were studied.Linear relationships between the fluorescence intensity and mass concentration of As and Hg found were in the ranges of 0.20-100.00 and 0.01-80.00 μg·L-1,with detection limits (3S/N) of 0.06 μg·L-1 and 0.006 μg·L-1,respectively.Values of RSD′ (n=11) of the method found were less than 5%.The proposed method was applied to the analysis of samples of tap water and landscape water.Using these samples as matrixes,tests for recovery were made by standard addition method,values of recovery found were 100.2%,104.9% for arsenic,and 98.0%,101.0% for mercury.