Preparation of Gluconic Acid by Oxidation of Glucose with Hydrogen Peroxide

Hydrogen peroxide (H 2 O 2 ) is a strong oxidant that oxidizes the hemiacetal hydroxyl to carboxyl group in glucose. In this study, gluconic acid was prepared by oxidation of glucose with H 2 O 2 , and the pH of the mixture was monitored during the preparation. The pH of the mixture was affected by the reaction time, temperature and H 2 O 2 concentration. Under the optimal conditions, i.e. reaction time of 70 min, reaction temperature of 80C and 12% H 2 O 2 , the minimum pH of the reaction mixture was 3.28. Extended reaction times, high temperatures and high H 2 O 2 concentrations did not further decrease the pH of the mixture. High‐performance liquid chromatography and liquid chromatography‐mass spectrometry indicated that the resulting product contained 79.02% gluconic acid and 14.48% glucose. Results demonstrated that the oxidation of glucose with H 2 O 2 could be a promising method for the preparation of gluconic acid. Practical Applications Gluconic acid can be prepared by oxidation of glucose with H 2 O 2 and could be of practical food and medicine applications.