Carbonized π-conjugated polymer-coated porous silica: preparation and evaluating its extraction ability for berberine

In view of the limitations of existing berberine solid-phase extraction adsorbents, this paper proposes a novel carbonized pi-conjugated polymer-coated porous silica (SiO2@C-pi-CP) adsorbent with simple process and low cost for efficient extraction of berberine by multiple interactions. Characterization methods, including Brunner-Emmet-Teller measurement, thermogravimetric analysis, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques, were used to verify the successful modification of carbonized pi-conjugated polymer on the surface of porous silica. The berberine was selected as target molecule, and the adsorption mechanism and process were investigated through adsorption kinetics, adsorption isotherms, and thermodynamic studies. The fitting results show that the adsorption of berberine by SiO2@C-pi-CP well conforms to the pseudo-second-order and Langmuir models. By optimizing the main SPE parameters, the SPE method based on SiO2@C-pi-CP was developed. Excellent results were obtained, including low limit of detection (0.75 ng mL(-1)) and limit of quantification (2 ng mL(-1)), wide linearity (2-13,000 ng mL(-1)), and satisfactory relative standard deviations (RSD) of inter-day (1.5%) and intra-day (6.2%). Finally, the SiO2@C-pi-CP also has been successfully used to the enrichment of berberine in real urine samples. This research makes clear that SiO2@C-pi-CP has outstanding potential for trace enrichment of berberine alkaloids.

Automated summary

This paper proposes a novel carbonized pi-conjugated polymer-coated porous silica adsorbent for efficient extraction of berberine alkaloids. The adsorption of berberine by SiO2@C-pi-CP conforms to the pseudo-second-order and Langmuir models. The developed SPE method based on SiO2@C-pi-CP achieves excellent results in terms of detection limit, linearity, and relative standard deviations.