ISSN:
0951-4198
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
An Approach which allows the determination of the specific effects of experimental parameters on the extent of reduction observed in fast-atom bombardment/liquid-assisted secondary-ion mass spectrometry (FAB/LSIMS) has been developed. The methodology is based on the isolation of the different components-background, reduction extent, and isotopic abundances - which contribute to peak intensities in the molecular-ion cluster. The individual contributions of reduction and background are calculated by an algorithm SRBC (simulated reduction and background calculations) which utilizes a Monte-Carlo method to optimize the values obtained for these variables. This approach has been used to examine the effects of analyte concentration, primary-beam energy and beam density on the extent of reduction in FAB/SIMS experiments. The results obtained indicate that the beam energy has no significant effect on the apparent reduction, as measured by the experimental (A+2)/A isotope peak ratio, while analyte concentration and beam density effects are obseerved. However, background and reduction data generated by SRBC demonstrate that in some cases there is little effect of these parameters on the true reduction of the analyte and that the increase in apparent reduction with the variation in these parameters results mainly from an artefact created by an increase in the background signal at lower concentrations and higher beam densities.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/rcm.1290060802
