Carrier solution, displacement chromatography

Displacement chromatography is characterized by the introduction of a discrete volume of sample into the chromatographic column that has been previously equilibrated with a weak mobile phase, termed the carrier. This carrier is chosen so that the individual components of the sample (the solutes) are significantly retained by the stationary phase. The displacement is accomplished by following the sample with a new mobile phase containing some concentration of the displacer, a molecule with a higher affinity for the stationary phase than that of any of the solutes. The solutes are displaced from the stationary phase by the higher-... 

Following elution of the isotachic train and the displacer solution from the column, the column must be regenerated and reequilibrated with the carrier before any subsequent displacement separation. This reequilibration step can be lengthy and is frequently considered a major Umitation to efficient displacement operation. Displacement chromatography requires the competitive isotherms of the solutes and the displacer to be convex upward and to not intersect each other. (See the entry Distribution Coefficient for related information.)... 

---