Exploration of deep eutectic solvent-based microextraction for quercetin monitoring in plant samples

This study delves into utilizing a microextraction process based on deep eutectic solvents (DES) for determining quercetin (QUR) levels in plant samples. The preparation of the DES involves a choline chloride (CC) to 1, 2-propanediol (PR) in a 1:4 ratio for efficient quercetin extraction. Through multivariate procedures, critical microextraction variables such as extraction time, pH, solvent volume, salinity, and sodium chloride were optimized to enhance quercetin extraction efficiency. Using the proposed procedure, the best response was found with a DES volume of 149 µL, extraction time of 4 min, pH 3.3, and salinity 2.9 % W/V sodium chloride with Desirability = 1. The method exhibited a detection limit of 9.8 ng mL⁻¹ and an enrichment factor of 61-fold for quercetin. The working range for detection was determined to be 30–5000 ng mL⁻¹. These findings highlight the efficacy of the developed microextraction method for accurately determining quercetin levels in plant samples with favorable recoveries in the range of 99.15 % −101.27 %.