A simple colorimetric method for the quality control of 1-alkyl-3-methylimidazolium ionic liquid precursors

Abstract
A simple colorimetric method to monitor the production of ionic liquid precursors is developed, which is based on the determination of 1-methylimidazole with copper(II) chloride. The synthesis of 1-ethyl-3-methylimidazolium chloride, an industrially important ionic liquid precursor, can be followed and the purity of the final product can be readily assessed in a quick and convenient manner.