[Recent progress of covalent organic frameworks as chromatographic stationary phases]

Chromatography is an important separation technique that has been widely applied in environmental monitoring，life sciences，food safety，and pharmaceutical analysis. As the core of chromatographic separation technologies，the stationary phase plays a decisive role in separation performance. Although silica-based stationary phases have been extensively used in chromatographic separations，their further application is severely limited by inherent drawbacks，such as complicated preparation procedures，high mass transfer resistance，and narrow applicable pH ranges. Therefore，the development of novel stationary phases that simultaneously exhibit high chemical stability and excellent separation performance to meet diverse separation requirements has remained a long-standing research focus in the field of chromatographic analysis. Covalent organic frameworks （COFs），as an emerging class of porous crystalline materials，possess distinctive advantages such as large specific surface areas，well-defined and ordered pore structures，and high chemical and thermal stability. These characteristics not only enable COFs to overcome the limitations of conventional chromatographic materials，including slow mass transfer and narrow applicable pH ranges，but also allow for precise recognition and selective separation of target analytes through rational functionalization of their pore structures. Consequently，COFs have been widely recognized as highly promising candidates for the construction of high-performance chromatographic stationary phases. This review systematically summarizes recent advances in the application of covalent organic framework （COF）-based stationary phases for gas chromatography （GC） and liquid chromatography （LC） over the past two years. Emphasis is placed on the rational structural design and performance modulation of COF materials，with particular attention to their applications in the broad-spectrum separation of organic compounds，positional isomer discrimination，and enantioseparation. The underlying separation mechanisms and structure-property relationships are discussed in detail. In light of the current research status and existing challenges，future development directions and potential applications of COF-based chromatographic stationary phases are further discussed，aiming to provide insights for the continued advancement of this emerging field.