Mechanisms of separation using the ternary mixture di-chloromethane-ethanol-water in high-performance liquid chromotography

The mechanisms of separation using the ternary system dichloromethane— in high-performance liquid chromatography were investigated. The use of an eluent saturated with water results in a separation based on partition of the component between a polar stationary phase, held in the pores of the porous support, and an apolar mobile phase percolating through the packed bed. Selective separations according to an adsorption mechanism are obtained by using an eluent partially saturated with water, corresponding to a point outside the miscibility gap of the three solvents.