Purpose: A pressure-assisted capillary zone electrophoresis method (pCE) was developed to determine the thermodynamic acidity constants (pKa) of phosphocreatine and rate constant of its hydrolysis reaction under acidic conditions.
Materials and Methods: Performed in an uncoated fused-silica capillary under separation voltage of 18 kV and 50 mbar of external pressure applied simultaneously.
Results: The running temperature was controlled at 25°C. The thermodynamic pKa values were calculated using the effective mobility (μeff) of the analyte against pH values of Background Electrolytes (BGEs) ranging from 1.7 to 12.1 with constant ionic strength of 25 mM. The hydrolysis kinetic studies under acidic conditions were conducted and the corresponding rate constants obtained with the pH range of between 2.0 to 7.0.
Conclusions: It could be found that the pCE method was convenient and more applicable to accurately determine the pKa values with degradant coexisted.