An effervescence‐assisted dispersive liquid–liquid micro‐extraction of captopril based on hydrophobic deep eutectic solvent

Synthesis of magnetic molecular imprinted polymer with a new functional monomer for dispersive micro solid phase extraction of captopril from wastewater and biological samples and determination by UV-Vis spectrophotometry

A magnetic molecularly imprinted polymer (MMIP) was fabricated for captopril by surface polymerization of Fe₃O₄@SiO₂ nanoparticles using a new functional monomer of N-(allylcarbamothioyl)-2-chlorobenzamide. It was then employed as a selective nanosorbent for dispersive magnetic micro solid phase extraction (DM-μ-SPE) of captopril from biological and wastewater samples. To characterize the physicochemical properties of the MMIP, different analytical methods such as the vibrating sample magnetometer, field emission scanning electron microscopy, Brunauer-Emmett-Teller, and Fourier transform infrared spectroscopy were utilized. To gain the maximum extraction recovery of captopril, the influence of various operating conditions was investigated and experimental settings optimized. After the extraction step, the concentration of captopril was measured by UV-Vis spectrophotometer at 245 nm. The assessments demonstrated that the MMIP provides higher extraction efficiency in comparison to magnetic non-imprinted polymer, suggesting the establishment of selective recognition binding sites at the MMIP surface. The method depicted desirable figures of merit of a low detection limit of 0.16 μg L^-1, a limit of quantification of 0.50 μg L^-1, a linear dynamic range of 0.50-22.0 μg L^-1, and an acceptable preconcentration factor of 333. The magnetic MIP was successfully employed for preconcentration and extraction of trace amounts of captopril in real samples, such as human blood serum, urine, and wastewater samples, with recoveries in the range 95.7 to 102.6% and relative standard deviations < 5%.

Combination of microwave-assisted solvent extraction and effervescence-assisted deep eutectic solvent-based in-syringe dispersive liquid-liquid microextraction and its application in the extraction of triazine pesticides from apple samples

In the current study, combination of microwave-assisted solvent extraction combined with effervescence-assisted deep eutectic solvent-based in-syringe dispersive liquid-liquid microextraction has been developed as a new sample pretreatment method. The offered method was used for the extraction of five triazine pesticides (atrazine, propazine, cyanazine, ametryn, and simazine) from apple samples before their determination by gas chromatography-flame ionization detection. For this purpose, briefly, the apple sample was contacted with a suitable acidified extraction solvent and the mixture was exposed to microwave irradiations. Then, the supernatant was taken and mixed with a few microliters of a low-density deep eutectic solvent. The supernatant phase containing the extracted analytes was injected into sodium bicarbonate solution filled into a syringe. Consequently, the effervescence reaction occurs and the analytes were extracted into the fine droplets of extractant dispersed throughout the solution. Afterward, an aliquot of this phase was analyzed by the chromatographic system. Satisfactory outcomes including high enrichment factors (228-261) and extraction recoveries (67-87%), good repeatability (relative standard deviations equal or less than 3.2 and 5.3% for intra- and inter day precisions), and low limits of detection (0.4-0.7 ng g^-1 ) and quantification (1.4-2.3 ng g^-1 ) were acquired under the best experimental situations. This article is protected by copyright. All rights reserved.

An effervescence-assisted dispersive liquid-liquid microextraction based on three-component deep eutectic solvent for the determination of fluoroquinolones in foods

An effervescence-assisted dispersive liquid-liquid microextraction approach using three-component deep eutectic solvent based on short-chain and medium-chain carboxylic acids and terpenoid was developed for the first time. The microextraction procedure was applied to the determination of fluoroquinolone antibiotics in foods (milk and shrimp samples) by high-performance liquid chromatography with fluorometric detection. In this microextraction procedure three-component deep eutectic solvent acted as a proton donor agent and an extractant. The carbon dioxide bubbles caused by the fast reaction between precursor of deep eutectic solvent (short-chain carboxylic acid) and effervescent agent (sodium carbonate) promoted the dispersion of the extractant in an aqueous sample phase. Various carboxylic acids were studied as hydrogen bond donors for the formation of deep eutectic solvents and proton donor agents for the generation of CO₂ bubbles. Two natural terpenoids (menthol and thymol) were studied as the hydrogen bond acceptors for the formation of three-component solvent. The extraction system based on heptanoic acid and thymol (1:2, mol/mol) containing formic acid (proton donor for generating CO₂ bubbles) provided maximum extraction recovery (86-99%) and a higher extraction efficiency of analytes compared to their extraction into individual hydrophobic precursors of the system. The LODs, calculated from the blank tests based on 3σ, were varied from 0.03 to 0.06 μg L^-1 and from 0.3 to 0.6 μg kg^-1 for fluoroquinolone antibiotics in milk and shrimp samples, respectively. The proposed approach provided effective dispersion of extractant speeding up the extraction process and fast separation of phases without any external energy assistance.