Understanding the effects of ionic liquids and antisolvent addition on the extraction and recovery of Pinus radiata bark components

Abstract Ionic liquids (ILs) are being increasingly explored as extraction solvents due to their tunable properties, which can control their ability to dissolve an array of solutes. IL selection requires an in-depth understanding of the consequences of IL structure on extraction outcomes for different substrates. Here, 14 ILs containing cations and anions that have been systematically modified to examine key structural effects have been explored for the extraction of chemical components from Pinus radiata bark. The extraction efficiency relative to the mass of bark ranged from 4 to 70%, and the isolation of bark components was evaluated using antisolvent addition. Extraction outcomes highlighted the importance of the IL anion in affecting extraction efficiency and selectivity, with a secondary role from the IL cation, and point toward a simple route for improving the overall selectivity of biomass extractions through control of the antisolvent addition process.