Sm. Eggins et al., DEPOSITION AND ELEMENT FRACTIONATION PROCESSES DURING ATMOSPHERIC-PRESSURE LASER SAMPLING FOR ANALYSIS BY ICP-MS, Applied surface science, 129, 1998, pp. 278-286
Citations number
21
Categorie Soggetti
Physics, Applied","Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
We have used an ArF excimer laser coupled to a quadrupole inductively
coupled plasma mass spectrometry (ICP-MS) for the measurement of a ran
ge of elements during excavation of a deepening ablation pit in a synt
hetic glass (NIST 612). Analyte behaviour shows progressive volatile e
lement enrichment at shallow hole depths, with a change to refractory
element enrichment as the ablation pit deepens further. Examination of
ablation pit morphology and the surface condensate deposited around t
he ablation site reveals the importance of sequential condensation of
refractory. then volatile phases from the cooling plasma plume after t
he end of the laser pulse. We interpret the observed element fractiona
tion behaviour to reflect a change in ablation processes from photothe
rmal dominated to plasma dominated mechanisms. The development of the
surface deposit is greatly reduced by ablating in an ambient atmospher
e of ne instead of Ar and is accompanied by a two- to four-fold increa
se in ICP-MS sensitivity. (C) 1998 Elsevier Science B.V.