Determination of mercury by cold vapour atomic absorption spectrometry after preconcentration with dithizone immobilized on surfactant-coated alumina

Mercury(II) and methylmercury cations at the sub-ppb level were adsorbed quantitatively from aqueous solution onto a column packed with dithizone immobilized on sodium dodecyl sulfate coated alumina. The trapped mercury was then back-extracted into the aqueous phase with 1 hr hydrobromic acid and determined by cold vapour atomic absorption spectrometry by utilizing the reaction with sodium tetrahydroborate. Mercury(II) and methylmercury cations were completely recovered from water with a preconcentration factor of 100. The analytical procedure was applied to the determination of mercury(II) and methylmercury in river and tap water.