Preparation Of Boronate Affinity Materials And Study Of Its Properties In Separating And Enriching Cis-diol Molecules

Boronate affinity materials have been widely used in the selective separation and enrichment of cis-diol molecules, such as catecholamine, nucleosides, saccharides and glycopeptides. This selectivity comes from the formation of reversible pH-dependent cyclic esters between cis-diol molecules and boronic acids on the surface of the material. However, most of them are prepared via the activation of materials with a double active-group molecule followed by bonding with phenylboronic acids. The binding capacities of the resulting materials are not satisfactory due to the limited binding sites on the material surface. Therefore, significant effort is still being made to develop new methods for preparation boronate affinity materials with high capacities. To solve this issue, we synthesized high binding capacity boronate affinity adsorbent via surface modification of silica by combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization, and used for selective separation and enrichment of cis-diol-containing compounds in plasma. The thesis includes the following two parts:(1) We prepared a high-capacity boronate affinity adsorbent via the combination of SI-ATRP using 3-acrylamidophenylboronic acid as monomer and chain-end functionalization technology by "click chemistry". The boronate affinity adsorbent characterized by Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA) and the structures of the silica particles. It possesses high binding capacities of 513.6 μmol/g for catechol and 736.8 μmol/g for fructose, which are much higher than those of other reported adsorbents. The proposed strategy was combination of ATRP and chain-end functionalization, which could serve as a promising new alternative for surface modification.(2) We also investigated adsorption performance of the boronate affinity adsorbent and researched the application of separation and enrichment of cis-diol molecules. The results demonstrated that the adsorbent possesses excellent selectivity. The proposed adsorbent was used in SPE-HPLC-UV analysis of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma. The adsorbent could eliminate interferences efficiently and yielded a recovery range of 85.6 to 101.1% with relative standard deviations ranging from 2.5 to 9.7% (n=5). Compared with other methods, the proposed adsorbent possesses the advantages of less dosage and higher sensitivity and accuracy. It has the potential to effectively analyze cis-diol substances in real samples.