Aqueous two-phase system based on double protic ionic liquid and acetonitrile as a platform to selective extraction of female hormones

In recent years, environmental concern over hormones that act as endocrine disruptors has increased because of their adverse effects on organisms. Moreover, they can reach the aquatic environment and persist due to their physicochemical characteristics. In this context, this work aims the selective extraction of hormones based on aqueous two-phase systems (ATPS) composed of acetonitrile (ACN) + double protic ionic liquids (PILs) + water. The respective pseudo-ternary phase diagrams were determined at 25°C. The systems were able to extract selectively two hormones for each phase, progesterone (PROG) and 17β-estradiol (E2) preferentially migrated to the ACN-rich phase, while estriol (E3) 17α-ethinylestradiol (EE2) has a higher affinity for the PIL-rich phase. ATPS reached the maximum extraction using systems formed by 50 wt% of each PIL in a single-step: E2 (99.58%), PROG (99.33%), E3 (99.76%) and EE2 (99.75%). In summary, the combination of double PILs and ACN as phase-forming components of ATPS, as well as their compositions, clearly leads to better extraction efficiencies on the partition of hormones.