CHM 2123 Study Guide - Elution, Ethyl Acetate, Supersaturation
Document Summary
Chromatography is most reliable and rapid method separating mixtures. Greek for colour and initially it was used to separate coloured compounds. In chromatography, mixtures are separated according to differences in their distribution between two phases. In chromatography, the mixture to be separated is dissolved in the mobile phase and the resulting solution is passed through the stationary phase which show a substance"s affinity toward each phase. Rf value describes the movement of the compound on a tlc plate. This value is determined by the compound displacement (d1) divided by the displacement of the solvent front (ds) The rf value is a measure of polarity in a compound. Where small rf value will indicate a polar molecule that moved slowly through the silica gel, and large rf value will indicate a non-polar molecule that moved fast through the silica gel. It is a process to separate different compounds by using their solubility in two immiscible solvents, called phases.
