Kiran Qadeer, Tania Mirza, Zufi Shad, Iqbal Ahmad.
Photodegradation of Cyanocobalamin in the Presence of Ascorbic Acid.
Baqai J Health Sci Jan ;14(1):13-5.

The photodegradation of cyanocobalamin at pH 4.0 in the presence of ascorbic acid has been studied. Hydroxocobalamin has been identified as a major degradation product of the reaction. Cyanocobalamin and hydroxocoblamin in degraded solutions have been assayed at 550 and 525nm by a two-component spectrophotometirc method in which ascorbic acid does not interfere. The apparent first-order rate constants for the photodegradation of cyanocoblaamin at pH 4.0 are in the range of 2.21-2.70×10-3 min-1. These values indicate that the photodegradation of cyanocobalamin is enhanced in the presence of ascorbic acid by mutual interaction and needs protective measures to control the degradation of the vitamin.

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