Determination of the hydrolysis rate constants and activation energy of aesculin with capillary electrophoresis end-column amperometric detection

J Chromatogr A. 2005 Dec 9;1098(1-2):194-8. doi: 10.1016/j.chroma.2005.10.029. Epub 2005 Nov 8.

Abstract

Aesculetin is the product of the hydrolysis reaction of aesculin. A high sensitivity and good repeatability method based on capillary electrophoresis with amperometric detection (CE-AD) was developed for simultaneous determination of aesculin and aesculetin in the hydrolysate of aesculin. Under the optimum condition: 10mmol/L KH(2)PO(4)-5mmol/L Na(2)B(4)O(7) (pH 6.0) buffer, separation at 18kV and +900mV (versus Ag/AgCl) as the detection potential, the hydrolysis rate constants of aesculin hydrolysis at 25, 30, 35, 40 and 45 degrees C in 0.1mol/L KOH were obtained as 1.45x10(-2)min(-1), 2.01x10(-2)min(-1), 2.93x10(-2)min(-1), 3.76x10(-2)min(-1) and 5.05x10(-2)min(-1), respectively. It was calculated that the activation energy for aesculin hydrolysis was 49.4kJ/mol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Buffers
  • Electrochemistry
  • Electrodes
  • Electrophoresis, Capillary / methods*
  • Esculin / chemistry*
  • Esculin / metabolism
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Kinetics
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Umbelliferones / chemistry*
  • Umbelliferones / metabolism

Substances

  • Buffers
  • Umbelliferones
  • Esculin
  • esculetin