Recapitulation Of Basics:

As stated earlier in this unit, we are going to confine ourselves to liquid-solid chromatography (LSC) and liquid-liquid partition chromatography (LLC); both of them being operated on a column. While a sample mixture is injected within a liquid chromatographic column, it starts to migrate down the column under the influence of the mobile phase. During this procedure, several components of the mixture will begin to separate depending upon their affinity for the stationary phase in the presence of the mobile phase. The elements that are weakly retained through the stationary phase will pass through the column and be eluted earlier. Therefore, there will be peaks in the order in the resulting chromatogram. The robustly retained components will elute later, the relative separation being dependent upon the degree of retention through the stationary phase for each sample component. Therefore, the components pass down the column at different speeds which can be related to the distribution of each component in the stationary and mobile phases. The two forms of chromatography, (LSC) and (LLC), basically differ in the mechanism responsible for separation.