Fabrication of a monolithic adsorbent with multi-sites and its application in the extraction of active components from traditional Chinese medicine formula

A vinylic functionalized covalent organic framework (V-COF) was introduced to the preparation of a porous organic polymer (POP)/V-COF monolithic cartridge, via one-step polymerization reaction in a 50-mm-long and 4.6-mm-inner diameter stainless steel column. The fabricated POP/V-COF monolith was characterized with scanning electron microscope, Fourier transform infrared spectrometer and specific surface area measuring instrument, which indicate that the monolithic material in the cartridge occupies porous structure, multiple functional groups and high specific surface area of 188.2 m2 g−1. The POP/V-COF monolith was used as a solid-phase extraction (SPE) cartridge, which was online combined with an octadecyl-silane analytical column of high-performance liquid chromatography (HPLC) to extract, enrich and detect dihydrotanshinone Ⅰ, cryptotanshinone, tanshinone I and tanshinone ⅡA from traditional Chinese formula of POP/V-COF adsorbent. Furthermore, the POP/V-COF cartridge was used to extract and enrich the bornyl acetate from the Salvia Miltiorrhiza Drink by offline SPE procedure, and the extractive solution was subsequently analysed using capillary-gas chromatography method. These results show that the POP/V-COF SPE cartridge can remove the matrices of the Salvia Miltiorrhiza Drink, and simultaneously can extract the target active components with specific selectivity. Quantitative methodology validation indicates the applicable of this method for determination of the four active components in Salvia Miltiorrhiza Drink with the fabricated online SPE-HPLC. It is worth noting that the present cartridge can be reused for at least 100 times, with the RSD values based on the peak areas of the four components are less than 6.3% (n = 100).