Abstract:An analysis method for the determination of trace impurity element arsenic in the nano-titanium dioxide by microwave digestion - graphite furnace atomic absorption spectrometry (GF-AAS) was established. A mixture digestion reagent which consist of a certain concentration and proportion of hydrofluoric acid and nitric acid were used in the sample digestion experiments. The nano-titanium dioxide samples were quickly and completely digested by high pressure microwave heating technology. The microwave heating control program were optimized. The new method not only solves the problem of difficult digestion of titanium dioxide and the loss of the analyte arsenic due to its evaporation during the high temperature digestion process, but also avoids the erosion of GF-AAS graphite tube due to the low acidity of the test solution. Furthermore, the type of graphite tube, graphite furnace atomization procedures and atomic absorption spectrometer detection parameters have been optimized through the matrix effect testing experiments, and thus the influence of the thermally stable titanium dioxide matrix on the determination of volatile trace element arsenic was eliminated. The detection limit the method is 0.02 μg/L. The recovery rate is in the range of 93.0% to 106.0%. The RSD is less than 9.4%. The results are consistent with those by ICP-MS method.