A green and rapid deep eutectic solvent dispersed liquid–liquid microextraction with magnetic particles-assisted retrieval method: Proof-of-concept for the determination of antidepressants in biofluids

In this study, a green and rapid method called deep eutectic solvent dispersed liquid–liquid microextraction with magnetic particles-assisted retrieval (DES-DLLME-MPAR) was proposed, which was applied for extracting antidepressants from biofluids as a proof-of-concept. Vortex-assisted DES extraction enabled rapid extraction and reusable magnetic particles was utilized to assist in the rapid retrieval of the DES. Ethanol, also low in toxicity, was used as the desorption solvent. Optimal conditions for the extraction were achieved as follows: 10 μL of DES composed of methyltrioctylammonium bromide and capryl alcohol in a molar ratio of 1:3 as the extraction solvent, a sampling solution pH of 10.0, a vortex time of 1 min for both extraction and desorption, 10 mg of magnetic particles for assisting DES retrieval, and a desorption solution of 100 μL ethanol. Under these conditions, the extraction recoveries were above 83.4 % and the whole extraction procedure could be completed in approximately 3 min. Linear calibration curves in the concentration range of 0.01–10.00 μg/mL were obtained for four antidepressants, with correlation coefficients exceeding 0.999. The limits of quantification ranged from 0.068 to 0.092 μg/mL, meeting the demand for therapeutic drug monitoring. Satisfied accuracies (relative recoveries: 93.8–111.6 %) and precisions (RSD ≤ 6.0 %) were achieved. The detection selectivity was enhanced by the efficient removal of the interferences. Three greenness evaluation metrics collectively demonstrate the excellent greenness of the developed method. The proposed DES-DLLME-MPAR method was rapid, green, simple, inexpensive and accurate, offering a promising alternative approach for the analysis of hydrophobic drugs in clinical biofluids.