Approaches used in the reduction of the buffer electrolysis effects for routine capillary electrophoresis procedures in pharmaceutical analysis

A quantitative study of continuous flow‐counterbalanced capillary electrophoresis for sample purification

“…Zwitterionic buffers are known to perform particularly well in this regard. Because of their minimal charge, these buffers promote increased sample introduction and also generate very little current and have been extensively used in E k injection to improve sample loading, as well as to increase the number of injections that can be successfully performed from the same sample vial [21]. Additionally, the use of a low-conductivity buffer can also minimize the negative effects of buffer depletion.…”

Parameters affecting reproducibility in capillary electrophoresis

“…Buffer electrolysis due to the prolonged application of voltage leads to poor quantitation due to the pH gradient that is generated across the capillary. Kelly et al [10] found that these problems could be reduced by using high capacity buffers or zwitterionic buffers. An alternative way of reducing buffer depletion is the use of short-end injections, which reduce the analysis time [8].…”

“…Faller and coworkers [21] demonstrated that the choice of the flushing buffer solutions could play an important role in migration time reproducibility. Temperature variations and corresponding changes in viscosity have been determined to be detrimental to obtaining reproducible results [2,10,20,28,29]. With an increase in temperature the viscosity decreases, the rate of EOF increases, and buffer depletion occurs more rapidly.…”

Enantiomeric purity determination of propranolol by capillary electrophoresis using dual cyclodextrins and a polyacrylamide-coated capillary

“…The overall analysis time was 23 min. With the extended analysis times buffer depletion [8] becomes an issue, with fewer assays possible before the buffer vials require changing.Therefore an enhanced method for enantiopurity of the propranolol drug substance was developed using a combination of a polyacrylamide-coated capillary and a mixture of CD chiral selectors. Combinations of charged and neutral CDs have been shown to give enhanced separations when compared to use of either charged or neutral CDs alone [9±11].…”