Separation of 1-(4-tert.-butylphenyl)-4-(4-hydroxypiperidinyl)-butan-1-one and its O-alkylated isomer by capillary zone electrophoresis

Abstract This paper describes the development and the validation of a capillary zone electrophoresis (CZE) method for the separation of position isomers: 1-(4- tert. -butylphenyl)-4-(4-hydroxypiperidinyl)-butan-1-one (hydroxybutyridine) and 1-(4- tert. -butyphenyl)-4-(piperidin-4-yloxy)-butan-1-one (O- (O-alkylated compound). In order to fix the optimum buffer pH the theoretical estimation of p k a is used. Rapid and efficient separation is shown with very low detection and quantification limits and excellent detection linearity. Good values of precision and accuracy were obtained as well as ruggedness and robustness.