Hydrophilic interaction liquid chromatography with indirect ultraviolet detection for the separation and quantification of pyrrolidinium ionic liquid cations

A method of hydrophilic interaction liquid chromatography with indirect ultraviolet detection was developed to determine three pyrrolidinium ionic liquid cations, i.e. N-methyl-N-ethyl pyrrolidinium cation ([MEPy]+), N-methyl-N-propyl pyrrolidinium cation ([MPPy]+) and N-methyl-N-butyl pyrrolidinium cation ([MBPy]+). Chromatographic separation was achieved on a hydrophilic column using imidazolium ionic liquids and organic solvents as the mobile phase. The effects of the background ultraviolet absorption reagents, the imidazolium ionic liquids, detection wavelength, organic solvents, column temperature and the pH value of the mobile phase on the separation and determination of pyrrolidinium cations were investigated and the retention behaviors in hydrophilic interaction chromatography were discussed. The optimized chromatographic conditions were selected. Under the optimal conditions, the detection limits (S/N = 3) for [MEPy]+, [MPPy]+ and [MBPy]+ were 0.59, 0.53 and 0.46 mg/L, respectively. The method has been successfully applied to the determination of the three ionic liquids synthesized in our chemistry laboratory. This research results may improve the analytical method of ionic liquid cations.

The determination of N-methyl-N-ethyl pyrrolidinium cation ([MEPy]+), N-methyl-N-propyl pyrrolidinium cation ([MPPy]+) and N-methyl-N-butyl pyrrolidinium cation ([MBPy]+) by hydrophilic interaction liquid chromatography with indirect ultraviolet detection is reported.Figure optionsDownload as PowerPoint slide