REDUCTION OF POTASSIUM CHROMATE BY D-FRUCTOSE, D-GALACTOSE, D-MANNOSE, D-GLUCOSE, AND L-SORBOSE

Chromate is readily reduced by various saccharides under different experimental conditions, and its reduction has been followed using absorption and EPR spectroscopies and electrochemistry. The reduction of Cr(VI) was found to be characteristic of the saccharide used and the reductive capabilities follow a trend, D-fructose > L-sorbose > D-galactose > D-mannose > D-glucose at pH 1.65 and D-fructose > D-galactose > D-mannose > L-sorbose > D-glucose at pH 0.35. Similar trends were noticed from EPR and electrochemistry studies. As the reduction of chromate was found to go via soluble, reactive, and relatively long-lived Cr(V) intermediates having different life times, the biological toxicity and ecological hazard created in the presence of Cr(VI) salts by various molecules containing such saccharide moieties is expected to follow a reverse trend.