Analysis of the diffusive properties of vitamin C aqueous solutions by quasi elastic neutron scattering. 1.

Quasi elastic neutron scattering (QENS) results on aqueous solutions of L-a scorbic acid (vitamin C) are reported. Data were collected by the IRIS spec trometer at the ISIS facility on partially deuterated L-ascorbic acid in D2 O and on hydrogenated L-ascorbic acid in H2O to clearly separate the diffus ive dynamics of hydrated L-ascorbic acid from that of water. The data analy sis furnishes quantitative evidences of a random jump diffusion motion of h ydrated L-ascorbic acid and reveals that the diffusive dynamics of the neig hboring water molecules is strongly affected by the presence of L-ascorbic acid.