Only a 15% of the known compounds lend themselves to analyze by gas chromatography owing to insufficient volatility or thermal instability. Liquid column chromatograph does not have this limitation. The interchange or combination of solvents can provide special selectivity effects that are absent when the mobile phase is a gas. Ionic compounds, liable naturally occurring compounds, polymers and high molecular weight poly functional compounds are conveniently analyzed by liquid
column chromatography was achieved by gravity, modern Liquid chromatograph uses high pressure pumps with relatively short, narrow-bore columns containing small particles of packing.