Abstract: The concentrations of sucrose and its hydrolysis products were directly monitored by capillary electrophoresis-electrochemical detection due to its high resolution and high sensitivity of detection. The rate constants of sucrose hydrolysis at different temperatures in 0.80 mol/L HCl and 0. 90 mol/L HCl were obtained from the concentration change of sucrose during the process of hydrolysis. At 25℃, 30℃ and 35 ℃, the measured rate constants of sucrose hydrolysis were 7. 81×10^-3 min^-1, 17. 44×10^-3 min^-1 and 33. 09×10^-3 min^-1 in 0. 80 mol/L HCl, and 11.18×10^-3 min^-1, 27. 32×10^-3 min^-1 and 44. 86×10^-3 min^-1 in 0. 90 mol/L HCl, respectively, from which the E_a value of 109. 85 kJ/mol was derived. Compared with the traditional polarimetric method, this method is more visualizable and convenient with satisfactory results.

Key words: Capillary electrophoresis, Electrochemical detection, Sucrose, Hydrolysis rate constant