IONIC LIQUIDS AS PROMISING FUNCTIONAL MATERIALS FOR MICROEXTRACTION OF STEROID HORMONES

Prospects for the use of imidazolium ionic liquids (IL) as extractants of sex steroid hormones (estrogens and androgens) in microextraction methods (dispersive liquid-liquid microextraction, DLLME, and magnetic solid-phase microextraction, mSPME) are identified. The key parameters of DLLME using CMImNTf IL, affecting the extraction efficiency, are optimized using the design of experiment method. High degrees of recovery (88–99 %) are achieved. An approach of dynamic IL immobilization on the surface of magnetic nanoparticles (MNPs) for steroid extraction under mSPME conditions is proposed. Two types of MNP pre-coating are studied: hydrophilic based on silica and hydrophobic with oleic acid. The capabilities of CMImBF IL as a MNP surface modifier for efficient steroid extraction are revealed. Optimum conditions provided high degrees of recovery (83–97 %), with the exception of estriol (60 %). The detection limits are 0.26–1.29 ng/mL. Limitations of the method related to partial removal of IL from the surface of NPs are revealed, which reduces the reproducibility of the results for estriol.