Sample Derivatization in Separation Science

Abstract Chromatographic methods have made so much progress that they are today the method of choice in analytical laboratories. Not all molecules can be separated by the desired method. Derivatization reactions are simple chemical modification of the sample that will render it compatible with the selected separation method. Gas chromatography ( GC ) can separate volatile and thermostable compounds. The possible derivatization reactions that will enhance both volatility and thermal resistance of the solutes are summarized and the protocols are outlined. Liquid chromatography ( LC ) can separate solutes soluble in the mobile phase. The main problem is to detect them. Derivatization reactions in LC will modify the solutes adding a chomophore for easy UV detection or a fluorophore for sensitive fluorescent detection. Different protocols including pre‐ or postcolumn reactions are described. Capillary electrophoresis ( CE ) separates solutes by difference in electrophoretic mobility. Derivatization reactions in CE are similar to derivatization in LC when detection is the problem. On‐column and postcolumn derivatizations are common in CE . Derivatization to change the solute electrophoretic mobility can also be performed.