Electrochemically modulated liquid chromatography (EMLC) as a probe of the adsorption characteristics of monosubstituted benzenes at porous graphitic carbon

摘要

The utility of electrochemically modulated liquid chromatography (EMLC) as a probe of the adsorption characteristics of monosubstituted benzenes at porous graphitic carbon (PGC) is investigated. An analysis on the extent of the changes in retention as a function of applied potential (E_(appl)) is performed to develop preliminary insights into the critical interactions between these compounds and PGC. The results show that the retention, and therefore the extent of adsorption, of these compounds increases as E_(appl) becomes more positive. Furthermore, the dependence of the increase varies between compounds, reflecting differences in the sensitivities of the adsorption strengths to π-donor/acceptor interactions. Together, these results demonstrate the potential value of EMLC as (1) a tool for investigating fundamental issues related to the adsorption of organic compounds on electrode surfaces and (2) a separation technique for mixtures of this important class of analytes.