Liquid-liquid equilibrium data for the ternary system based on ionic liquid + organic solvents + water at 298 K and atmospheric pressure applied in antidepressant partitioning

Abstract

Antidepressants are drugs widely used in nervous disorders, such as anxiety, depression, and panic, and are eliminated through the urinary system. In bodies of water, they present high persistence and toxicity, even at low concentrations, conforming to the classification of emerging micropollutants. This work addresses the construction of phase diagrams for different biphasic systems, based on ionic liquids (ILs) and organic solvents, and their subsequent application in the partitioning of antidepressants such as fluoxetine hydrochloride, paroxetine hydrochloride and sertraline hydrochloride. The phase diagrams were measured gravimetrically at 298.15 ± 1.00 K and atmospheric pressure using the turbidity method. The ILs of the imidazolium family, with shorter chain length [C2mim]+, were the only ones able to form biphasic systems using 1,3-dioxolane. The driving force for phase separation is the comparison of hydrophobic/hydrophilic characteristics between the constituents. In this sense, the pair of constituents [C2min][OAc] and 1,3-dioxolane provided the phase diagram with the largest biphasic area. The partitioning of antidepressants was studied in systems formed by IL (25 wt%) + 1,3-dioxolane (50 wt%) + water (25 wt%) containing 1.05 µg·L−1 of fluoxetine hydrochloride, 1.42 µg·L−1 of paroxetine hydrochloride or 0.23 µg·L−1 sertraline hydrochloride at 298.15 ± 1.00 K and atmospheric pressure. The partitioning followed the characteristics of antidepressant σ-profiles generated through COSMO-RS. The recoveries were high, and the proposed systems were shown to promote the selective isolation of pairs of these antidepressants.