HPLC Post Column Derivatization

HPLC is a technique that separates mixtures into their respective component substances using adsorption, ion exchange or partitioning effects to move the substances through a packed column (stationary phase) at different rates of speed. The separation relies on the relative polarity or strength of a solvent (mobile phase) competing with the strength of the packing to attract sample molecules. The molecules that are most strongly attracted to the mobile phase elute early while those molecules strongly attracted to the packing elute later. Slight differences in the molecular structure of sample molecules can result in separation due to chemical forces that occur in the column.