Buffer Type, Concentration, and pH

Solely phosphate and borate or their mixtures are generally employed as buffer in MEEKC at low concentrations (5-20 mM) to produce EOF without an increment of high-current intensity [42], 

Low concentrations of salts generate high-speed microemulsion [51] and higher concentrations suppress the EOF and generate higher current, which limits the applied voltage for operation [42], 

Organic solvents such as methanol, acetonitrile, 2-propanol have been added to the microemulsion to improve resolution of the analytes, specially those with strong hydrophobicity [53]. The addition of the organic solvents increases the viscosity of the electrolyte reducing the EOF and thus increasing the migration time of the analytes. The addition of cyclodextrins allows to resolve enantiomeric drugs or analytes with closely related structure [46,47]. 

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