Selective extraction of female hormones using aqueous two-phase system composed of double protic ionic liquid + acetonitrile

Abstract

Estrogens are currently considered the most prescribed drugs in the world. These contaminants are not entirely metabolized by humans and therefore, they have been detected in different effluents. Several studies already demonstrated that the hormones are classified as the major responsible for causing endocrine changes in living organisms. 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 ATPS pseudo-ternary phase diagrams, were determined at 298.15 ± 1.00 K and 0.10 ± 0.01 MPa. Thereby, their performance as extraction strategies was evaluated using four hormones (Progesterone, 17β-estradiol, estriol and 17α-ethinylestradiol). The binodal curve follows the order of PILs hydrophobicity, exhibiting intermediate biphasic region size between systems using the single PILs. 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 (K > 1), while estriol (E3) 17α-ethinylestradiol (EE2) has higher affinity for the PIL-rich phase (K < 1). Maximum extraction was reached using ATPS formed by 50% of each PIL in a single-step: PROG (99.93%), E2 (99.92%), E3 (99.90%) and EE2 (99.92%). The results obtained show that ATPS based on ACN + double PIL allow the selective extraction of hormones.