Nanofluid of magnetic-activated charcoal and hydrophobic deep eutectic solvent: Application in dispersive magnetic solid-phase extraction for the determination and preconcentration of warfarin in biological samples by high-performance liquid chromatograph

In this study, for the first time, nanofluid of magnetic-activated charcoal and hydrophobic deep eutectic solvent (AC@Fe3 O4 -DES) based dispersive magnetic solid-phase extraction was successfully applied for the determination and preconcentration of warfarin in plasma and urine samples. The hydrophobic DES was prepared by mixing tetramethylammonium chloride (as hydrogen bond acceptor) and thymol (as hydrogen bond donor) and acted simultaneously as both carrier and stabilizer for magnetic nanoparticles. In this method, the nanofluid as a new extraction solvent was rapidly injected into the aqueous sample, which led to improvement of the mass transfer of the analytes into the sorbent and reduction of the extraction time. In the screening step, the fractional factorial design was applied for selecting some important parameters which significantly affected the extraction procedure. The effective parameters were then optimized by Box-Behnken design. Under the optimal conditions, the limits of detection were in the range of 0.3-1.6 ng/ml. A good linear range was observed in the range of 1.0-500.0 ng/ml for water and 5.0-500.0 ng/ml for urine and plasma. The intra- and inter-day relative standard deviations were 2.7-3.2 and 1.9-4.5% for five replications, respectively. Based on the results, the proposed method was successfully applied for the determination of warfarin in biological samples, using high-performance liquid chromatography.

Nooraee Nia N ，Hadjmohammadi MR 《-》

Hydrophobic borneol-based natural deep eutectic solvents as a green extraction media for air-assisted liquid-liquid micro-extraction of warfarin in biological samples.

In the present study, a new generation of water-immiscible natural deep eutectic solvents (DESs) was synthesized using borneol as a hydrogen-bonding acceptor and decanoic acid, oleic acid, and thymol as a hydrogen-bonding donor in different molar ratios. These green hydrophobic solvents which are chemically stable in aqueous solutions were used as extraction solvents for isolation and pre-concentration of warfarin in biological samples. In this method, fine droplets of DESs were dispersed into the sample solution by using the air-assisted liquid-liquid micro-extraction method to accelerate the cloudy emulsion system formation and increase the mass transfer of the analyte to the DES-rich phase. The borneol based deep eutectic solvent is a worthy generation of the extraction solvents in the ALLME method due to low-cost and less toxicity. A Plackett-Burman design was utilized for screening the experimental parameters. The effective parameters were then optimized by Box-Behnken design (BBD). Optimized extraction conditions were pH of sample solution of 3.9, number of aspiration/dispersion cycles of 15, the volume of DES of 60 μL, and rate and time of centrifuge of 6000 rpm and 10 min, respectively. Under the optimized conditions, the developed NADES-ALLME method exhibited a wide linear range of 5-500 µg L - 1 for plasma and urine samples with satisfactory recoveries above 88.80%. Limit of detections (LODs) and Limit of quantifications (LOQs) of warfarin were in the ranges of 0.5-2.7 and 1.65-8.91, respectively. The enrichment factors were obtained in the range of 148-164 and precisions were lower than 5.87%. Finally, the proposed method was successfully employed for the analysis of warfarin in human urine and plasma samples.

Majidi SM ，Hadjmohammadi MR 《-》

Combination of dispersive solid phase extraction and deep eutectic solvent-based air-assisted liquid-liquid microextraction followed by gas chromatography-mass spectrometry as an efficient analytical method for the quantification of some tricyclic antidep

A dispersive solid phase extraction coupled with deep eutectic solvent-based air-assisted liquid-liquid microextraction has been developed and applied to the extraction and preconcentration of some tricyclic antidepressant drugs in the human urine and plasma samples prior to their determination by gas chromatography-mass spectrometry. In this method, a sorbent (C18) is first added into an alkaline aqueous sample and dispersed by vortexing. By this action, the analytes are adsorbed onto the sorbent. Then, the sorbent particles are isolated from the aqueous solution by centrifugation. Afterward, a deep eutectic solvent, prepared from choline chloride and 4-chlorophenol is used to desorb the analytes from the sorbent. Subsequently, the supernatant solution is removed and added into an alkaline deionized water placed into a test tube with a conical bottom. The resulting mixture is rapidly sucked into a glass syringe and then injected into the tube. This procedure is repeated for several times and a cloudy solution consisting of fine droplets of deep eutectic solvent dispersed into the aqueous phase is formed. After centrifuging the obtained cloudy solution, the tiny droplets of the extractant, containing the extracted analytes, settle at the bottom of the tube. Finally, an aliquot of the extractant is taken and injected into the separation system for quantitative analysis. Several significant factors affecting the performance of the proposed method are evaluated and optimized. Under optimum extraction conditions, the method shows low limits of detection in the ranges of 5-10, 8-15 and 32-60 ng L-1 in deionized water, urine, and plasma, respectively. Enrichment factors are observed to be between 325 to 385 in deionized water, 155 to 185 in urine, and 64 to 72 in plasma. Extraction recoveries are in the range of 65-77 (in deionized water), 62-74 (in urine), and 64-72% (in plasma). The relative standard deviations of the proposed method are ≤ 6% for intra- (n = 6) and inter-day (n = 4) precisions at a concentration of 200 ng L-1 of each analyte. Finally, the applicability of the introduced method is investigated by analyzing the selected drugs in different biological fluids. In the proposed method, for the first time, a deep eutectic solvent composed of safe, cheap, and biodegradable compounds was synthesized and used (at μL-level) as an elution and extraction solvent, simultaneously which led to omit the consumption of toxic organic solvents. This represents a significant advantage in the era of green chemistry. In addition, the introduced method is sensitive, simple in operation, rapid, and efficient.

Mohebbi A ，Yaripour S ，Farajzadeh MA ，Afshar Mogaddam MR ... -  《-》

Alcohol-based deep eutectic solvent as a carrier of SiO(2) @Fe(3) O(4) for the development of magnetic dispersive micro-solid-phase extraction method: Application for the preconcentration and determination of morin in apple and grape juices, diluted and a

In this study, a hydrophilic deep eutectic solvent was synthesized as a carrier and disperser of magnetic nanoparticles based on ferrofluid and used to develop the dispersive micro-solid-phase extraction method. Ethylene glycol/tetramethylammonium chloride deep eutectic solvent and SiO2 @Fe3 O4 were used to provide the highly stable ferrofluid with strong sorbing properties without any additional stabilizer, which was employed to extract and determine morin in apple and grape juices, diluted and acidic extract of dried onion, and green tea infusion samples. The dispersibility of SiO2 @Fe3 O4 and prevention of its aggregation in the sample solution were improved using the deep eutectic solvent-based ferrofluid. Also, it facilitated the fast injection of sorbent into the sample solution that led to an increase of the contact surface between the sorbent and analyte, and reduction of the extraction time and consumption of the sorbent. The important experimental parameters influencing the extraction efficiency of morin were examined. Under the optimal conditions, a linear calibration curve was obtained in the range of 3-500 µg/L with a determination coefficient of 0.9994. The limits of detection and quantification were of 0.91 and 2.98 µg/L, respectively. While an extraction recovery of 97.7% with relative standard deviation of 3.8% (interday) was obtained via three replicated measurements on a 30 µg/L of morin standard solution, the enrichment factor was 39.1. Finally, this method was successfully used to extract and preconcentrate morin in various samples, followed with their determination by high-performance liquid chromatography with ultraviolet detection.

Majidi SM ，Hadjmohammadi MR 《-》

Deep eutectic solvent magnetic bucky gels in developing dispersive solid phase extraction: Application for ultra trace analysis of organochlorine pesticides by GC-micro ECD using a large-volume injection technique.

Novel deep eutectic solvent (DES) magnetic bucky gels (MBG) were formed by choline chloride/urea deep eutectic solvent and magnetic multi-walled carbon nanotube nanocomposite (MMWCNT) and were used in developing dispersive solid-phase extraction (dSPE) method. The hydrophilic DES based MBGs were developed with the features of magnetic susceptibility to permit fast injection of sorbent into the aqueous sample, rapid retrieval of the sorbent, high dispersion of MWCNT in water and compatibility with GC. In this work we investigated the application of DESs as a new class of carriers for CNT based nanofluids. In this gel DES acts simultaneously as a carrier and stabilizer for MMWCNT nanoparticles. By combining the MWCNT nanocomposite and DES, a highly stable (stability against sedimentation) viscous magnetic bucky gel or soft material was prepared without any additional stabilizer. This gel possesses fluidity, stability, magnetic properties and the unique strong sorbing properties of MWCNT simultaneously. We used the advantages of this magnetic DES based soft material in developing a new DES magnetic bucky gel based dispersive solid phase extraction. By coupling this method with GC- micro ECD and using large-volume-injection technique we achieved low LOD values which is a necessity in the ultra trace analysis of organochlorine pesticides (OCPs) in environmental water samples. Under the optimized conditions, the enrichment factors were in the range of 270-340. The limits of detection were between 0.04 and 0.27ng/L and the relative standard deviations were <10%. This method was successfully used for the determination of OCPs with good reproducibility and recovery.

Yousefi SM ，Shemirani F ，Ghorbanian SA 《-》