抄録
This study examined the interaction between saccharide and aqueous solution with salts using mid-infrared (MIR) spectroscopy. Since the saccharide-water interaction in the biological products is closely related to the other components such as salts, the direct and simultaneous measurement of the structure and concentration of plural biomolecules in consideration of those interactions is desirable. In this work, we took up alkaline metal chlorides, and studied the influence of the kinds and the concentration of those chlorides on the MIR spectral characteristics of glucose which plays very important role in the organisms. The five types of alkaline metal chlorides (LiCl, NaCl, KCl, RbCl, and CsCl) were used. Each chloride was dissolved into pure water and glucose solution (2.0 M) with different concentrations until the saturated state. Their infrared spectra were collected by use of a Fourier transform infrared spectrometer equipped with an attenuated total reflectance accessory. For each alkaline metal chloride, with the variation of those concentrations, the different spectral patterns were found at the absorption bands of OH stretching and bending vibration in the spectra of both aqueous solutions and solutions with glucose. In addition, we compared the spectral patterns of glucose in the aqueous solution with those in the solution with chlorides. Results showed that, in the fingerprint region spectra, the absorption intensity at the bands of glucose increased with the increase of chlorides concentrations. With these results, we could understand the spectral characteristics of the interactions between glucose and alkaline metal chlorides by using MIR spectroscopy.
