Comparison of mixed-mode anion-exchange performance of N-vinylimidazole-divinylbenzene sorbent.

A newly synthesized copolymer based on N-vinylimidazole-divinylbenzene (NVIm-DVB) was evaluated as a mixed-mode anion-exchange sorbent for SPE, since the NVIm monomer apart from its hydrophilic properties can be protonated at a certain pH, and then performs as an anion-exchanger. To investigate the behavior of the NVIm-based sorbent, the SPE performance was evaluated under reversed-phase (RP), weak anion-exchange, and strong anion-exchange conditions. The results for the NVIm-DVB sorbent were also compared to commercial reference sorbents from each group: Oasis HLB, Oasis WAX, and Oasis MAX, respectively. SPE results from this evaluation showed that NVIm-DVB can be used as an RP material, compared to Oasis HLB. It also has the potential to act as a strong anion-exchange sorbent, compared to Oasis MAX, since under the proper conditions it was able to fraction and quantitatively recover a group of selected solutes.