Measurement of dissociation constants (pKa values) of organic compounds by multiplexed capillary electrophoresis using aqueous and cosolvent buffers.

Evaluation of a multiplexed capillary electrophoresis (CE) method for pK(a) measurements of organic compounds, including low solubility compounds, is presented. The method is validated on a set of 105 diverse compounds, mostly drugs, and results are compared to literature values obtained from multiple references. Two versions of the instrument in two different labs were used to collect data over a period of 3 years and inter-laboratory and inter-instrument variations are discussed.