Novel asymmetric 1,3-di(alkyloxy)imidazolium based ionic liquids for liquid-phase microextraction of selected analgesics and estrogens from aqueous samples

In this study, four novel and pure room temperature ionic liquids were synthesized from basic chemicals and examined on their applicability as extraction media for liquid-phase microextraction of selected analgesics and estrogens from aqueous samples. Analyses were performed with high-performance liquid chromatography equipped with ultraviolet detection. The molecular structures of newly synthesized ionic liquids were elucidated by nuclear magnetic resonance spectroscopy. Three different extraction experiments were performed to verify their suitability as extraction media in liquid-phase microextraction. Recoveries and enrichment factors were calculated and extraction time profiles recorded to evaluate their extraction performance. Under optimized conditions high recoveries (84–92%) and acceptable enrichment factors (36–68) were obtained for the extraction of naproxen, ibuprofen, estrone and estradiol from aqueous samples. Extraction time profiles showed that equilibrium was reached after 40–80 min depending on analyte and applied ionic liquid. The proposed method was also tested on complex water samples from the nearby river (Inn) in which case same recoveries and enrichment factors were obtained. Calibration curves were linear with a coefficient of determination ranging from 0.9992 to 0.9997 for a concentration level between 2 and 20 μg mL−1. Limit of detection and limit of quantification were calculated according to DIN 32645:2008-11 for the four analytes an...
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research