Applications of 1.06-micron IR laser desorption on a Fourier transform mass spectrometer

Anal Chem. 1998 Dec 1;70(23):4890-5. doi: 10.1021/ac980914s.

Abstract

Various sugars, peptides, and lipids were analyzed on a Fourier transform mass spectrometer using laser desorption and ionization with and without the assistance of matrixes. A compact Nd:YAG laser with an output at 1.06 microns corresponding to fundamental frequency was employed. Gram-negative and Gram-positive bacteria were also subjected to laser desorption mass spectrometry. Characteristics ions of conjugated lipid, formed by attachment of alkali metal cations, endogenous to the cells, were observed. Particle/liquid matrixes (e.g., cobalt in glycerol) proved to be useful with the 1.06-micron laser. The particles absorb efficiently laser radiation in a broad wavelength range. The liquid provides the same advantages as in fast atom bombardment: increased signal-to-noise ratios and enhanced sample lifetimes. The effect of laser power on total ion current was shown to differ for samples with and without the particle/liquid matrix. The Fourier transform analyzer provides MS/MS capability for both positive and negative ions from complex mixtures. Ions desorbed externally are introduced into the cell via a quadrupole ion guide with a lower mass cutoff. Such a setup allows matrix ions to be excluded and thus provides excellent signal-to-noise ratios for lower mass range fragment ions formed inside the cell.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus / chemistry
  • Erwinia / chemistry
  • Lasers*
  • Molecular Weight
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Spectroscopy, Fourier Transform Infrared / methods*
  • Substance P / chemistry

Substances

  • Substance P