A novel software tool for high throughput measurements of interconversion barriers: DCXplorer.

The software program DCXplorer is introduced to directly access interconversion rate constants in dynamic chromatography and electrophoresis. The program utilizes the unified equation of chromatography which can evaluate reaction rate constants of all kinds of first order reactions of processes taking place during a separation process. Evaluations with DCXplorer are facilitated by a graphical user interface which allows zooming into the area of interest of an interconversion profile and calculating reaction rate constants without a time consuming simulation process. DCXplorer was applied to determine the enantiomerization barrier of the diuretic drug chlorthalidone by pressure supported dynamic capillary electrokinetic chromatography (DEKC) under acidic conditions at pH 5.00 and pH 3.75. Activation parameters DeltaH(++) and DeltaS(++) were obtained from temperature dependent measurements between 15.0 and 35.0 degrees C in 5 K steps at pH 3.75 and between 30.0 and 50.0 degrees C in 10K steps at pH 5.00.