Molecularly imprinted polymer based potentiometric sensor for the determination of 1-hexyl-3-methylimidazolium cation in aqueous solution

Abstract

The molecular imprinting technique is powerful to prepare functional materials with molecular recognition properties. In this work, a potentiometric sensor was fabricated by dispersing molecularly imprinted polymers (MIPs) into 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. The as-prepared electrode exhibited a Nernstian response (58.87 ± 0.3 mV per decade) to [C6mim]+ in a concentration range from 1.0 × 10−6 to 0.1 mol kg−1 with a low detection limit of 2.8 × 10−7 mol kg−1, high selectivity, and little pH influence. The as-prepared electrode was used for the detection of the [C6mim]+ in distilled water, tap water, and river water with a good recovery. 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.