RESOLUTION OF INFRARED-SPECTRA AND KINETIC-ANALYSIS OF MUTAROTATION OF D-GLUCOSE IN WATER BY SEQUENTIAL RANK ANALYSIS

Mutarotation of D-glucose in water has been studied by attenuated total internal reflectance Fourier-transform infrared spectrometry. Infrared spectra of solutions of both alpha-D-glucose and beta-D-glucose in water were acquired at regular time intervals. The spectral profiles of the evolving mixtures were first-order differentiated and sequential rank analysis was used to obtain the concentration profiles of the anomers. The concentration profiles were subsequently used to obtain resolved infrared spectra of the two anomers. A crucial assumption for the resolution procedure used in this work is that the spectral peaks of the pure anomers are symmetric in the proximity of local maxima or minima. Rate constants for the conversion of alpha- to beta-glucose and for the conversion of beta- to alpha-glucose have been calculated from the concentration profiles. The calculated rate constants as well as equilibrium concentrations derived from them agree well with previously reported values.