The determination of 1-methylimidazole in room temperature ionic liquids based on imidazolium cation by cyclic voltammetry

The voltammetric behaviors of room temperature ionic liquids (RTILs) are affected by many factors, including the structure of cation and anion, experimental conditions, impurities and so on. In this work, the determination of 1-methylimidazole (1-MIm) was explored in three imidazolium ionic liquids by virtue of cyclic voltammetry. On the anodic scans, the oxidation peaks of 1-MIm were observed for tested samples, and the linear correlation of the oxidation peak current against the concentration of 1-MIm could be established by standard addition method. The obtained results showed that the limits of detection reached 20–35ppm while the limits of quantification were less than 100ppm. Moreover, the influences of halide ions on the determination of 1-MIm in RTILs were also studied emphatically. It was found that the effect might arise from the reaction between 1-MIm and chlorine or bromine generated from the oxidation of Cl− or Br−, since the response of tri-halide was disappeared in the presence of 1-MIm according to the results of cyclic voltammetry and UV–Vis spectroscopy. [Display omitted] •The oxidation of 1-methylimidazole in imidazolium-based ionic liquids was studied.•There are two oxidation peaks for the CV curves of 1-methylimidazole.•The limits of detection of 1-methylimidazole are about 20–35ppm.•The effects of water and halide were researched.