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Kinetics and mechanism of oxidation of chondroitin-4-sulfate polysaccharide by
chromic acid in aqueous perchlorate solutions

Research Authors
Refat Hassana, Samia Ibrahim, Abdel Rahman Dahy, Ishaq Zaafarany, Fahd Tirkistani b, Hideo Takagi
Research Abstract

The kinetics of chromic acid oxidation of chondroitin-4-sulfate polysaccharide as sulfated carbohydrates
at a constant ionic strength of 4.0 mol dm−3 has been investigated, spectrophotometrically. The reaction
kinetics showed a first-order dependence in chromic acid and fractional-first-order kinetics with respect
to the chondroitin-4-sulfate concentration. The influence of [H+] on the reaction rates showed that the
oxidation process is acid-catalyzed. Added Mn2+ ions indicated the formation of Cr(IV) as intermediate
species. A kinetic evidence for formation of 1:1 intermediate complex was revealed. The kinetic parameters
have been evaluated and a tentative reaction mechanism in good consistent with the kinetic results
obtained is discussed.

Research Department
Research Journal
Carbohydrate Polymers
Research Rank
1
Research Vol
Vol.92
Research Year
2013
Research Pages
PP.2321– 2326