摘要 |
A method for preparing a high-purity ionic liquid having a pH value of 7 and an elemental analysis deviation of less than 0.5 wt % between a calculated elemental analysis and a found elemental analysis for each of carbon, hydrogen and nitrogen, wherein the method comprises forming a monophasic or biphasic mixture of an ionic liquid and an inert liquid. When the monophasic mixture is formed, it is filtered to yield a filtrate from which the high-purity ionic liquid is recovered. When the biphasic mixtures is formed, it is separated into an aqueous phase and ionic liquid phase, whereby the ionic liquid phase is filtered to yield a filtrate from which the high-purity ionic liquid is recovered. Furthermore, the present purification procedure can be used for the clean-up of a contaminated ionic liquid by extracting it into a polar extractant to form an extract containing the ionic liquid. Water traces are removed from the extract. Then, the extract is filtered and the high-purity ionic liquid is recovered from the filtered extract.
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