Liquid–liquid extraction of strontium from acidic solutions into ionic liquids using crown ethers

90 Sr is one of the most monitored fission products. New efficient methods for strontium separation are therefore sought. Over the past 20 years, crown ethers solutions in ionic liquids (ILs) have been confirmed to efficiently extract strontium from acidic solutions. Despite all the work done in this field, the extraction mechanism is still not completely clear. Depending on experimental conditions, the extraction is believed to proceed either in the form of an ion-association complex [Sr·CE·(NO 3 ) 2 ] or via exchange between [Sr·CE] 2+ and two IL cations. This work aims to study the influence of several extraction parameters and compare them with the presumed mechanisms.