Deflection of laser-produced ions in laser-induced thermal-desorption/fourier-transform mass spectrometry for surface analysis.
A method for deflecting ions, such as K(+), produced outside a Fourier-transform mass spectrometer cell during laser-induced thermal desorption, is described. This technique has been shown to deflect laser-generated K and Ti ions from two Ti foil samples (biomedical implant model surfaces), yielding mass spectra of coadsorbed organic species. Further studies characterizing the laser desorption/deflection parameters have shown that ion deflection improves with higher deflection voltages and greater sample to Fourier-transform mass spectrometry cell separation. Higher laser power densities resulted in greater surface ion production; hence higher deflection voltages were necessary. A 6% increase in laser power necessitated a fourfold increase in deflection voltage for the Ti sample.
Department of Chemistry, University of California, 95616, Davis, CA, USA.
N A
NA
Thomburg
I M
IM
Abdelrehim
S
S
Pullins
D P
DP
Land