In-situ formation of a hydrophobic deep eutectic solvent based on alpha terpineol and its application in liquid-liquid microextraction of three β-blockers from plasma samples

Abstract

A new microextraction procedure based on liquid-liquid microextraction using a deep eutectic solvent has been used for the extraction of three β-blockers (atenolol, propranolol, and metoprolol) from plasma samples. The enriched analytes were analyzed by gas chromatography-mass spectrometry. In this study, both of the microextraction and synthesis processes were accelerated by using microwave radiations. In this procedure, 5 mL diluted plasma sample was transferred into a glass test tube and it was mixed with 0.20 g tetramethylammonium chloride. Then 0.5 mL of dimethylformamide (as a co-disperser) was mixed with 610 µL alpha terpineol and the mixture was dispersed into the solution to form a homogenous solution. The tube was placed under microwave radiations for 1 min. By doing so, tetramethylammonium chloride-alpha terpineol deep eutectic solvent was formed in sample solution as tiny droplets and the analytes were extracted into them. Then the tube was cooled with tap water and centrifuged for 5 min at 5000 rpm. Finally 1 µL of the deep eutectic solvent was injected into the determination system. Low limits of detection (0.130–0.205 ng mL−1) and quantification (0.435–0.692 ng mL−1), high extraction recovery (72–86%), and good precision (relative standard deviation ≤ 5.3%) were obtained. The introduced method was effectively applied for determination of the β-blockers’ concentrations in plasma samples.