Calculation of electrophoretic mobility in mixed solvent buffers in capillary zone electrophoresis using a mixture response surface method

摘要

The electrophoretic mobilities of three beta-blocker drugs, practolol, timolol and propranolol,have been measured in electrolyte systems with mixed binary and ternary water-methanol-ethanol solvents with acetic acid/sodium acetate as buffer using capillary electrophoresis. The highest mobilities for the analysts studied have been observed in pure aqueous, the lowest values in ethanolic buffers. The measured electrophoretic mobilities have been used to evaluate the accuracy of a methematical model based on mixture response surface method that expresses the mobility as a function of the solvent composition. Mean percentage error (MPE) has been computer considering experimental and calculated mobilities as an accuracy criterion. The obtained MPE for practolol, timolol and propranolol in the binary mixtures are between 0.9 and 2.6%, in the ternary water-methanol-ethanol solvent system the MPE was about 2.7%. The MPE values resulting from the proposed equation lie within the experimental relative standard deviation values and can be considered as an acceptable error.