Advances of covalent organic frameworks as the stationary phases for liquid chromatography

High performance liquid chromatography is widely used in various fields, such as food, medical, environmental, and biological areas. The stationary phase determines the chromatographic separation performance, including the resolution, sensitivity, analytical speed and precision. Recently, covalent organic frameworks (COFs) have been introduced to develop the stationary phases for liquid chromatography, which can provide hydrophobic, hydrophilic, π-π, electrostatic, halogen bond, hydrogen bond, and dipolar interactions, as well as molecular shape and chiral recognition selectivity. Further, the COF-based stationary phases have exhibited excellent separation performances for the different polar compounds, isomers, and enantiomers by several chromatographic modes, including reversed-phase, normal phase, and mixed-mode liquid chromatography. The advances of COF-based stationary phases are very important for analytical chemistry and separation science fields. So, the preparation and applications of COF-based stationary phases in liquid chromatography are summarized, and the current shortcomings and development perspectives are also described.