Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1240511 | Spectrochimica Acta Part B: Atomic Spectroscopy | 2012 | 7 Pages |
The abundance of metal argide (MAr+) ions during laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is measured during ablation of pure samples of transition metals. As expected, the relative abundance of MAr+ ions to M+ ions for various elements increases as the dissociation energy (D0) of the ion increases. Gas kinetic temperatures (Tgas) are determined from the calculated MAr+/M+ ratios and are used to indicate the origins of MAr+ ions. The determined Tgas values are very high, 8000 K to ≥ 20,000 K, which indicate that MAr+ ions are much less abundant in the mass spectrum than expected based upon plasma conditions. Collision-induced dissociation (CID) during the ion extraction process is suggested to be responsible for removal of MAr+ ions. Factors responsible for these collisions are discussed.
► MAr+ ions are less abundant than would be expected from Tgas conditions in the ICP. ► Errors in dissociation energies or mass bias do not account for the MAr+ abundances. ► Collision-induced dissociation of MAr+ ions during extraction is a likely cause.