Electrochemically modulated liquid chromatographic separation of triazines and the effect of pH on retention

Electrochemically modulated liquid chromatography (EMLC) manipulates analyte retention by changing the potential applied (Eapp) to a conductive stationary phase. This paper applies EMLC to the separation of a set of seven triazines which are commonly used but environmentally hazardous herbicides. Experiments herein examine the influence of Eapp and the pH of the mobile phase on triazine retention. The results are discussed in terms of: (1) retention of triazines of dissimilar acid strengths and by correlations with the pH of the mobile phase; (2) how changes in Eapp and acid–base equilibria modulate elution; (3) qualitative insights into EMLC-based retention; and (4) potential merits of EMLC in realizing the rapid separation of the seven-component triazine mixture.