Mobile phase is constantly fed into the column inlet at a constant rate by a pump. The sample is injected from a sample injector, located near the column inlet. The injected sample enters the column with the mobile phase and the components in the sample migrate through it, passing between the stationary and the mobile phases. Compounds move in the column only when they are in the mobile phase. Compounds that tend to be distributed in the mobile phase therefore migrate faster through the column while compounds that tend to be distributed in the stationary phase migrate slower. In this way, each component is separated on the column and sequentially elutes from the outlet. Each compound eluting from the column is detected by a detector connected to the outlet of the column.
PRINCIPLE OF RP-HPLC
In RP-HPLC compounds are separated based on their hydrophobic character.retension is the result of interaction of then nonpolar components of the solutes and the non-polar stationay phase. Figure 2 High Performance Liquid Chromatography