DIRECT DETERMINATION OF HEAVY-METALS AT PICOGRAM PER GRAM LEVELS IN GREENLAND AND ANTARCTIC SNOW BY DOUBLE FOCUSING INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

The potential of a double focusing ICP-MS instrument in terms of high sensitivity, sample throughput and low volume of sample consumed was i nvestigated for the direct, simultaneous determination of Co, Cu, Zn, Mo, Pd, Ag, Cd, Sb, Pt, Ph, Ri and U at the low and sub-pg g(-1) level in polar snow, The entire analytical procedure, including cleaning of material, field sampling, sample handling, determination of the blank s and instrumental analysis, is described. The mean concentrations det ected in snow samples collected in Central Greenland (2.7 m deep pit) are (in pg g(-1)): Co 5.8, Cu 4.6, Zn 47, Mo 1.6, Pd 1.1, Ag 0.60, Sb 0.86, Pt 0.61, Bi 2.5 and U 1.8, The Cd, Pb and U concentrations in a snow core section collected in East Antarctica are: Cd 0.39, Pb 5.0, U 0.04 pg g(-1). Repeatability of measurements ranges between 8 and 25% depending on the element considered. For some of the elements investi gated these results constitute the first available for polar snow, The results of direct analysis by double focusing ICP-MS on Cd and Pb in the Antarctic snow samples and on Zn and Cu in Greenland samples are c onsistent with those obtained by differential pulse anodic stripping v oltammetry (DPASV) and graphite furnace atomic absorption spectrometry (GFAAS), respectively.