K. Dittrich et al., DETERMINATION OF MERCURY BY FURNACE ATOMIC NONTHERMAL EXCITATION SPECTROMETRY, Spectrochimica acta, Part B: Atomic spectroscopy, 49(12-14), 1994, pp. 1695-1705
The determination of Hg using different variants of the Furnace Atomic
Nonthermal Excitation Spectrometry (FANES) is described. In the direc
t analysis of microvolumes of solutions, the results could be improved
by working with chemical modifiers for the stabilization of Hg during
the thermal pretreatment. The best results were obtained using Ir and
Pd as modifiers, with absolute detection limits of 4 and 12 pg, respe
ctively. The determination of mercury in sample volumes up to 10 ml co
uld be achieved by coupling a cold vapour generation system and an ama
lgam attachment to the FANES source. A detection limit of 22 ng/l was
obtained with this technique. The best results were obtained by using
the cold vapour generation technique and in situ enrichment of Hg onto
the modified inner surface of the graphite tube of the FANES source.
Using Ir for permanent impregnation of the tube a detection limit of 0
.0009 mu g/l was found. The influence of hydride forming elements on t
he determination of mercury by the technique of vapour generation and
in situ enrichment was studied. A reduction of the concentration of Na
BH4 to 0.002% m/v made it possible to determine traces of mercury in p
resence of a high excess of hydride forming elements without any depre
ssion of the Hg emission intensity. The results were validated using s
tandard reference materials.