Comparative investigations of the secondary ion emission of metal complexes under MeV and keV ion bombardment

Abstract

A series of ionic and neutral Group VIII transition metal complexes with molecular masses up to 2500 u were analysed by time-of-flight secondary ion mass spectrometry (SIMS) and plasma desorption mass spectrometry (PDMS). The secondary ion emission, the secondary ion yields and the yield ratios Y(PDMS)/Y(SIMS) of 20 ionic and neutral metal complexes were determined. Both techniques generally provide both molecular and fragment ion information. Characteristic fragmentation patterns give useful data for structural cbaracterization. Additionally, the stabilities of different secondary ion species were compared by their half-lives. Both PDMS and SIMS are very sensitive, yielding optimum spectra from total sample sizes as low as 5 nmol, and the sample consumption is negligible.( 1 ) D btai ;kh;ol e (chelat) = L, (N03-)2 Me = Pd, P t Figure 1 . General scheme of the investigated dicationic metal complexes (after Ref. 8).

Application of secondary ion and matrix‐assisted laser desorption‐ionization time‐of‐flight mass spectrometry for the quantitative analysis of biological molecules

“…Thus, in the case where the molecular species prefers cationization with the substrate material, surface coverage of the substrate (€I) will be inversely related to P(M --f Xy). Systematic studies have been carried out to determine the transformation probability for a variety of biomolecules (105,106), and as a general rule biomolecules less than 2,500 Da can be assumed to have a transformation probability of 1 Op4. The transformation probability depends not only on molecular size and structure, but also on surface environment.…”