  We use near infrared spectroscopy to obtain concentration dependent glucose
absorption spectra in their aqueous solutions in the near-infrared range (3800
- 7500 cm^{-1}). We introduce a new method to obtain reliable glucose
absorption bands from aqueous glucose solutions without measuring the water
displacement coefficients of glucose separately. Additionally, we are able to
extract the water displacement coefficients of glucose, and this may give a new
general method using spectroscopy techniques applicable to other water soluble
materials. We also observe red shifts in the absorption bands of water in the
hydration shell around solute molecules, which comes from contribution of the
interacting water molecules around the glucose molecules in solutions. The
intensity of the red shift get larger as the concentration increases, which
indicates that as the concentration increases more water molecules are involved
in the interaction. However, the red shift in frequency does not seem to depend
significantly on the concentration up to our highest concentration. We also
performed the same measurements and analysis with sucrose instead of glucose as
solute and compare.
