A novel lignin-bonded polymer monolithic column for multimodal interaction capillary liquid chromatographic...

A lignin-functionalized polymer monolithic stationary phase was successfully prepared by modifying an epoxy ring-containing methacrylate-based monolith and evaluated for capillary liquid chromatography of small aromatic analytes. The effect of polymerization duration on monolith morphology, permeability, and chromatographic performance was systematically investigated. Among the prepared columns, the monolith polymerized for 18 h showed the best overall performance, with a permeability of 3.02 × 10^-14 m² and an average macropore diameter of 1.2 ± 0.30 μm. After lignin immobilization, the modified monolith exhibited enhanced thermal stability and improved chromatographic efficiency, providing theoretical plate numbers of up to 43,500 plates/m for alkylbenzenes under reversed-phase conditions. The lignin-functionalized phase also demonstrated clear structure-recognition capability toward aromatic isomers, including terphenyl isomers and triphenylene. In addition, preliminary separation of selected insecticides showed measurable selectivity, indicating the suitability of this phase for structurally complex hydrophobic analytes. These results establish the lignin-bonded monolithic column as a promising reversed-phase stationary phase with multimodal interaction potential for small aromatic and structurally related compounds, while broader mode evaluation and real-sample validation remain important directions for future work.