ALTERNATIVE MERCURY PALLADIUM CHEMICAL MODIFIER FOR THE DETERMINATION OF SELENIUM IN COAL FLY-ASH BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

An alternative chemical modifier containing HgCl2-PdCl2 was used to develop an accurate method for the determination of selenium in coal fly ash. Wall atomization and the Smith-Hieftie background correction method were used. The determination was done either by the standard additions method or by using a calibration graph obtained for selenium in matrix-free solutions with the modifier. A detection limit of 7.45-mu-g l-1 and an optimum concentration range of up to 120-mu-g l-1 were obtained.