In this study, the metal−organic framework (MOF) material MOF-801 was synthesized and further derivatized to introduce C=C double bonds on its surface. Then, a MOF-801/polymer monolithic column was prepared using derivatized MOF-801, lauryl methacrylate and methacrylic acid as comonomers, ethylene glycol dimethacrylate as a cross-linker, n-hexanol as a porogen, and azobisisobutyronitrile as an initiator. After being characterized, the monolithic material was employed as a solid-phase extraction adsorbent to perform online enrichment and purification of vitexicarpin in Vitex trifolia, which was coupled with high-performance liquid chromatography. The enrichment factor reached up to 212.5. Under this condition, the content of vitexicarpin in the eluate was 60.63%, which was much higher than that in Vitex trifolia (0.03%). This method demonstrated excellent linearity within the range of 0.13 µg/mL to 5 × 102 µg/mL with a calibration equation of y = 0.63135x + 0.70981, and the correlation coefficient was 0.9992. The inter-day and intra-day precision was less than 1.63%. The recovery rate of vitexicarpin in Vitex trifolia was between 95 and 105%.
Liu et al. (Fri,) studied this question.