A green air assisted-dispersive liquid-liquid microextraction based on solidification of a novel low viscous ternary deep eutectic solvent for the enrichment of endocrine disrupting compounds from water.

A green air-assisted dispersive liquid-liquid microextraction based on floating organic droplet solidification (DLLME-SFOD) was introduced for the enrichment of five endocrine disrupting compounds (EDCs) from water using a ternary deep eutectic solvent (TDES) as an extracting solvent prior to their determination by HPLC-PDA. The eutectic solvents were synthesized by combining various fatty acids which can concurrently act as both hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD). Adding a third component to classical two-component eutectic solvents allows to purposefully control density, melting point, and viscosity of the synthesized solvents. Ternary and binary eutectic solvents with C9 acid provided excellent extraction efficiency in comparison with other eutectic solvents with C8 acid, while ternary solvents provided superior extraction efficiency to binary ones. Different variables that could influence the microextraction efficiency were optimized applying central composite face-centered design (CCF). At the optimum conditions, the method had low detection limits ranging from 0.96-2.30 µg/L with a preconcentration up to 134-folds. The method showed good linearity from the linear regression with an excellent correlation coefficient (r > 0.999). A good inter- and intraday precision (%RSD < 7%) and%recovery > 90% were achieved proving the method high precision and accuracy. Furthermore, the potential of using the TDES for determining the EDCs from five real water samples was proved through the higher extraction efficiency of the EDCs (90.06-104.43%) with results uncertainty < 20% for most of the compounds. Finally, the method greenness was evaluated by Raynie pictogram, analytical eco-scale, and Green Analytical Procedure Index (GAPI) approaches which confirm the superior eco-friendship of our method in comparison with other reported methods.