Preparation and Evaluation of Methacrylate-based Reversed-phase Sorbents for Solid-phase Extraction of Polar Compounds

In solid-phase extraction (SPE), hydrophilic-lipophilic balance (HLB) type sorbents prepared by copolymerization with divinylbenzene (DVB) and polar monomers are widely used. The hydrophobicity of the HLB-type sorbents depends on DVB as the main component, and the extraction efficiency for polar compounds is enhanced by interaction with the polar groups introduced by polar monomers. On the other hand, high adsorption ability, due to the hydrophobicity of DVB, adversely affects the rapid elution of trapped compounds. In this study, the non -aromatic sorbents that has high adsorption ability for polar compounds, and can rapidly elute polar compounds including aromatic rings were developed. Porous polymer particles were prepared with trimethylolpropane trimethacrylate (TMPT), and the solid-phase extraction characteristics were evaluated. By optimizing the pore characteristics of TMPT-type sorbent, it was possible to effectively extract the nucleobases and nucleosides whose extraction efficiency was comparable to that of the commercial HLB-type sorbent. Furthermore, in order to improve the hydrophobicity of the TMPT-type sorbents, non-aromatic sorbents copolymerized with stearyl methacrylate (SMA) were prepared. However, the adsorption abilities of the TMPT-type sorbent could not be improved. The adsorption and desorption properties of the non-aromatic sorbents were evaluated using the TMPT-type sorbent. The aromatic polar compounds were able to be strongly sorbed to the TMPT-type sorbent, but they could be rapidly eluted by low concentration organic solvent as eluent. These results suggest that the TMPT-type sorbents are useful for a solid-phase extraction of the polar compounds and will solve the problem of the poor desorption in the HLB-type sorbents containing DVB.