Ultrasound-assisted emulsification-microextraction of propranolol in plasma using a natural hydrophobic deep eutectic solvent for fluorescence detection: A green analytical approach

This study aimed to explore and assess the feasibility of measuring propranolol within the hydrophobic deep eutectic solvent (NHDES) as an extractant using a spectrofluorometer. Accordingly, the optimization and application of an ultrasound-assisted emulsification microextraction (USAEME) method, employing NHDES to extract propranolol prior to determination by a spectrofluorometer, were investigated. The NHDES was prepared using fatty acids, which act as both hydrogen bond acceptors and donors. The fluorescence spectra of propranolol in methanol, NHDES, and a mixture of methanol and NHDES were analyzed. The study further explored the selection of NHDES composition using a univariate method and examined the effects of other parameters including NHDES volume, pH, salt concentration, and sonication time through a multivariate optimization approach. Optimal extraction conditions were identified, and the method's analytical performance was validated using plasma samples. The calibration curve exhibited good linearity (R² = 0.9977), with limits of detection (LOD) and quantitation (LOQ) of 11.62 and 35.22 ng/mL, respectively. The method demonstrated excellent precision, making it a reliable technique for the extraction and quantification of propranolol in complex matrices. Additionally, the Complex Green Analytical Procedure Index (ComplexGAPI) tool was employed to evaluate the method's environmental impact, confirming its superior greenness compared to other methods.