Hydration occurs when some ionic species are in pure water. In this research study, optical properties of an electrolytic solution with ionic species that emulated the extracellular environment were analyzed. The attenuated total reflection ATR-FTIR spectra and Raman spectra of electrolyte solutions were measured and the vibrational spectra of pure water (type A) with electrolyte solutions in the spectral region between 2700-4000 cm ?1 was compared. At low ionic concentrations of chloride, sodium, potassium and calcium, a weak effect on the spectrum of water was observed. We found a shifts in the absorption bands of water in IR (3286 cm ?1 and 3492 cm ?1 ) and Raman spectra (3207 cm ?1 and 3432 cm ?1), which increase with ionic concentration. This effect can be interpreted as a result of interactions between water molecules and solvated ions. This result suggests that the presence of ions in pure water modifies the optical properties of water.