The usage of a solvent gradient is very nicely developed in column chromatography but is much less common in CCC. The extrusion of stationary section from the column at the tip of a separation experiment by stopping rotation and pumping solvent or fuel by means of the column was utilized by CCC practitioners before the term EECCC was suggested. In twin-mode, the cell and stationary phases are reversed half way by means of the separation experiment. As authentic stationary phases of paper chromat...