Differentiation of Methyl-glucopyranoside Anomers by Infrared Multiple Photon Dissociation with a Tunable CO₂ Laser

Abstract

Fragmentation of lithium cation-attached alpha- and beta-O-methyl-glucopyranoside precursor ions, formed by electrospray ionization (ESI) and trapped in a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer, was produced by infrared radiation from a tunable CO(2) laser. Irradiation over the wavelength range from 9.20 to 10.80 microm yielded unique fragmentation patterns that were a function of both product ion mass and laser wavelength. Comparison of the relative percent abundances of fragment ions for the two anomers revealed statistically significant differences for wavelengths between 9.20 and 9.70 microm at the 95% confidence level. On the basis of these results, differentiation of anomeric configurations of monosaccharides within oligosaccharides may be possible to address by wavelength-selective infrared multiple-photon dissociation (IRMPD).