Vibrational Spectroscopic Studies of L-Ascorbic Acid and Sodium Ascorbate.

Investigation ofL(+)-Ascorbic acid with Raman spectroscopy in visible and UV light

“…The solution spectrum in Figure 16 did not seem to change significantly when we added HCl, as also seen previously (39). The wavenumber values are given in Table 6 (solid) and Table 7 (solution).…”

“…As seen in Figure 16, the spectrum in the aqueous solution (top) is comparable to that of the crystalline phase (middle), except for the broad OH stretching feature at ∼3650 to ∼3070 cm −1 , as already discussed by Hvoslef and Klaeboe (39). This means that no drastic rearrangement of the structure occurs by dissolution in water compared with the crystal, although the conformer equilibrium might shift.…”

“…Some of the bands (arrows) were highly polarized, and the observations were used to confirm the assignments by comparison to the calculated polarization values. Raman spectra of deuterated and normal aqueous AH 2 solutions are shown and compared in Figure 18, complementing the results of Hvoslef and Klaeboe (39). The comparison reveals that many bands from isotopically undisturbed AH 2 Sodium ascorbate results are shown in Figure 19 and the wavenumber data are included in Table 7.…”

“…Measured Raman spectral bands (in cm ) and assignments for ascorbic acid and sodium ascorbate solids, compared to literature values (39,(44)(45)(46)48). Some data can also be found in Jehlička et al (47) Ascorbic acid…”

“…In 1971 Hvoslef and Klaeboe used a red helium-neon laser to study AH 2 as crystals and in aqueous dilution to supplement infrared absorption experiments. This pioneering work also included deuteration studies (39). Structure clarifications on l-ascorbic acid were later made by infrared (IR) and UV spectroscopy by, for example, Falk and Wojcik (40), Lohmann et al (41,42), and Ferrer and Baran (43).…”