DETERMINATION OF SELENIUM IN COAL FLY ASHES BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY USING A CADMIUM-PALLADIUM CHEMICAL MODIFIER

A simple and reliable method is described for the determination of selenium in coal fly ashes. Wall atomization and Smith-Hieftje background correction were used. A chemical modifier containing CdCl2-PdCl2 was used. Concentrations of selenium in coal fly ashes were calculated directly by a standard additions method. A detection limit of 7-mu-g l-1, a sensitivity of 1.37-mu-g 1(-1) and an optimum concentration range up to 100-mu-g 1(-1) were obtained. The characteristic integrated mass was 13.7 pg of selenium for an absorbance peak of 0.0044 s.