Determination of Trace Mercury in Copper Smelting Slag by Powder Introduction-Direct Mercury Analyzer

A method for determination of trace mercury in copper smelting slag by powder introduction-direct mercury analyzer was proposed. In the high-purity oxygen atmosphere, 0.15 g of the copper smelting slag sample was dried at 200 ℃ and thermally decomposed at 650 ℃ for 90 s. Then mercury was catalytically decomposed into mercury atoms and formed gold amalgam with gold. Mercury vapor was released at 850 ℃ and its characteristic absorption at 253.7 nm was measured. When the mercury mass were 1-20 ng and 20-400 ng, different standard curves were established between the absorbance and mass of mercury, with detection limit (3s) of 0.044 ng·g^-1. RSDs (n=11) of determined results of three copper smelting slag samples with different mercury contents were in the range of 1.7%-3.5%. Test of recovery was made by the standard addition method, giving results in the range of 91.2%-97.4%. There was no difference in determined results by this method and SN/T 2680-2010.