Molecularly Imprinted Polymer Based Potentiometric Sensor For The Determination Of Ionic Liquid Cations

Ionic liquids?ILs?have aroused extensive attention from the academia owing to their unique chemical and physical properties.Scientists and engineers are delving deeply into their synthesis,physicochemical property measurements,and fundamental researches and industrial applications.However,recently,many research results have shown that ILs have bad effects?such as the acute and chronic toxicity reaction,induction of teratogenesis and mutagenesis?on organisms.They may have different degrees of potential toxicity to the humen and environments.Their large-scale use would give rise to environmental pollution through accidental spills or effluents.The determination of ILs in aqueous solution is a basis to accurately assess their environmental impact,physicochemical properties,or basic and applied research.It is essential to develop an efficient method for the determination of ILs.Potentiometric sensors are easy-to-use devices that allow rapidly and accurately qualitative or quantitative analysis at relatively low concentration.Molecular imprinting technology?MIT?,a novel molecular recognition technology,can be used for the preparation of molecularly imprinted polymers?MIPs?.MIPs completely match with the template on three-dimensional structure and thus are prior to identify the template compared to other interfering ions.Combining the two together,it will bring a new opportunity and development for Ils' determination and application.As a part of Financial supports from the National Natural Science Foundation of China?Nos.21173070,21303044,21573058?,and Program for Innovative Research Team in Science and Technology in University of Henan Province?15IRTSTHN 003?,the main contents in this paper are as follows:1.A potentiometric sensor was fabricated by dispersing MIPs in plasticized PVC matrix,and used for the determination of 1-hexyl-3-methylimidazolium cation?[C₆mim]⁺?in aqueous solution.The MIPs were synthesized by precipitation polymerization,using 1-hexyl-3-methylimidazolium chloride?[C₆mim]Cl?as the template molecule,methacrylic acid?MAA?and ethylene glycol dimethacrylat?EGDMA?as the functional monomers,and EGDMA also as the cross-linking agent.2.The MIP-modified electrode exhibited a good Nernstian response in a wide concentration range of 1.0×10-6 to 1.0×10-1 mol·kg-1 with a lower detection limit.The electrode also demonstrated a good performance,such as a short response time,and a satisfactory long-term stability.The novel as-prepared electrode was successfully applied to the detection of the [C₆mim]⁺ in distilled water,tap water,and riverwater.It was also successfully applied in the determination of mean activity coefficients of [C₆mim]Br in fructose + water systems based on the potentiometric method at 298.15 K.3.According to the method for making MIP-based potentiometric sensor for the determination of[C₆mim]⁺,MIP-based potentiometric sensor for the determination of N-butyl pyridinium cation?[BPy]⁺?was prepared.The sensor showed a good response performance and the recoveries are in a reasonable range.This provides a reference for the preparation of MIP-based potentiometric sensor for other type of ILs.