HPLC Columns: Types, Selection Guide & Applications | Zodiac Life Sciences

What is a C18 Column? A C18 column is one of the most commonly used stationary phases in High-Performance Liquid Chromatography (HPLC) , particularly in reverse-phase chromatography . This column full form refers to "Octadecylsilane", which describes the chemical structure of the bonded phase: 18 carbon atoms (–C18H37) attached to silica particles. This HPLC column works by retaining compounds based on hydrophobic (non-polar) interactions. Non-polar analytes interact strongly with the hydrophobic stationary phase and elute more slowly, while polar compounds move through the column faster. This selectivity makes C18 columns highly effective for separating a wide range of chemical and biological compounds. C18 Column Structure and Chemistry The column structure consists of high-purity, porous silica particles bonded with octadecylsilane chains (C18) . The stationary phase is non-polar, while the mobile phase typically includes water mixed with organi...