Simultaneous Determination of Arsenic and Mercury in Sludge by Double Channel Atomic Fluorescence Spectrometry

The sample was dissolved with nitric acid-perchloric acid,and the method for the simultaneous determination of mercury and arsenic in sludge by double hannel atomic fluorescence spectroscopy was established.The digestion system,high voltage of PMT,lamp current,speed of carrying gas,shield gas flow and potassium borohydride concentration were investigated and optimized.The linearity ranges of method for arsenic and mercury were respectively 0.0—60.0ng/mL and 0.0—6.0 ng/mL with the correlation coefficients r great than or equal to 0.9998,and the detection limit of arsenic and mercury were all 0.03ng/mL with RSD less than or equal to 2%.The standard addition recoveries of the samples were in the rang of 91.0%—104.0% for arsenic and 90.0%—96.0% for mercury.This method is simple and rapid with high sensitivity,and that could be applied to simultaneously detecting arsenic and mercury in sludge.