Differentiation of closely related isomers: application of data mining techniques in conjunction with variable wavelength infrared multiple photon dissociation mass spectrometry for identification of glucose-containing disaccharide ions.

Data mining algorithms have been used to analyze the infrared multiple photon dissociation (IRMPD) patterns of gas-phase lithiated disaccharide isomers irradiated with either a line-tunable CO(2) laser or a free electron laser (FEL). The IR fragmentation patterns over the wavelength range of 9.2-10.

Direct evidence for the ring opening of monosaccharide anions in the gas phase: photodissociation of aldohexoses and aldohexoses derived from disaccharides using variable-wavelength infrared irradiation in the carbonyl stretch region.

All eight D-aldohexoses and aldohexoses derived from the non-reducing end of disaccharides were investigated by variable-wavelength infrared multiple-photon dissociation (IRMPD) as anions in the negative-ion mode. Spectroscopic evidence supports the existence of a relatively abundant open-chain configuration of the anions in the gas phase, based on the observation of a significant carbonyl absorption band near 1710 cm(-1). The abundance of the open-chain configuration of the aldohexose anions was approximately 1000-fold or greater than that of the neutral sugars in aqueous solution.

Differentiation of methyl-glucopyranoside anomers by infrared multiple photon dissociation with a tunable CO(2) laser.

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.