Topic overview

Start with the big picture

In paper chromatography, analytes partition between polar cellulose paper and a solvent that moves by capillary action. TLC uses a thin layer of silica or alumina and generally offers faster separation and better resolution than paper methods. HPLC pumps a liquid mobile phase through a packed column, supporting efficient, reproducible analysis and convenient coupling to detectors such as UV absorbance, fluorescence, or mass spectrometry. Paper and TLC results can be characterized by the retention factor (Rf), while HPLC uses retention time and peak area. The methods also differ in cost, quantitative performance, sample preparation, and clinical applications. These principles provide a foundation for understanding how chromatography supports qualitative and quantitative laboratory testing.