Isotope dilution inductively coupled plasma quadrupole mass spectrometry in connection with a chromatographic separation for ultra trace determinations of platinum group elements (Pt, Pd, Ru, Ir) in environmental samples
M. Muller et Kg. Heumann, Isotope dilution inductively coupled plasma quadrupole mass spectrometry in connection with a chromatographic separation for ultra trace determinations of platinum group elements (Pt, Pd, Ru, Ir) in environmental samples, FRESEN J AN, 368(1), 2000, pp. 109-115
An isotope dilution inductively coupled plasma quadrupole mass spectrometri
c (ID-ICP-QMS) method was developed for the simultaneous determination of t
he platinum group elements Pt, Pd, Ru, and Lr in environmental samples. Spi
ke solutions, enriched with the isotopes Pt-194, (108)pd, Ru-99, and Ir-191
, were used for the isotope dilution step. Interfering elements were elimin
ated by chromatographic separation using an anion-exchange resin. Samples w
ere dissolved with aqua regia in a high pressure asher. Additional dissolut
ion of possible silicate portions by hydrofluoric acid was usually not nece
ssary. Detection limits of 0.15 ng g(-1), 0.075 ng g(-1), and 0.015 ng g(-1
) were achieved for Pt, Pd, Ru, and Lr, respectively, using sample weights
of only 0.2 g. The reliability of the ID-ICP-QMS method was demonstrated by
analyzing a Canadian geological reference material and by participating in
an interlaboratory study for the determination of platinum and palladium i
n a homogenized road dust sample. Surface soil, sampled at different distan
ces from a highway, showed concentrations in the range of 0.1-87 ng g(-1).
An exponential decrease of the platinum and palladium concentration with in
creasing distance and a small anthropogenic contribution to the natural bac
kground concentration of ruthenium and iridium was found in these samples.