Combination of orthogonal array design and overlapping resolution mapping for optimizing the separation of heterocyclic amines by capillary zone electrophoresis

Abstract

This paper describes the application of combined orthogonal array design and overlapping resolution mapping to the optimization of capillary zone electrophoresis for the separation of heterocyclic amines. The factors affecting resolution, such as buffer pH, organic modifier, concentration of buffer solution, capillary tubing temperature, and electric field strength, were studied in two steps. In the first step, orthogonal array design was used to determine the most important factors and interactions. The experiments were carried out according to an OA16 (215) matrix through sixteen pre-designed trials. Based on the results of the first step, the second set of experiments was performed according to a three-dimensional overlapping resolution mapping scheme, in which eleven pre-planned trials were executed and global optimum conditions for the separation within a reasonable analysis time were obtained. The proposed conditions were successfully applied in the separation of thirteen heterocyclic amines.