Synthesis of a green high density deep eutectic solvent and its application in microextraction of seven widely used pesticides from honey.

A green dispersive liquid-liquid microextraction using a new high density deep eutectic solvent (as an extraction solvent) has been developed and utilized in the simultaneous preconcentration and extraction of seven pesticides in honey followed by gas chromatography-flame ionization detection. The deep eutectic solvent is synthesized using menthol (as a hydrogen bond acceptor) and dichloroacetic acid (as a hydrogen bond donor) at a molar ratio of 1:2. Initially the analytes are extracted into acetone from the sample. After centrifuging, the synthesized deep eutectic solvent is added to the extract obtained from the previous step. Then this mixture is quickly injected into deionized water by a syringe for more concentration. A cloudy solution is formed by dispersion of fine droplets of the deep eutectic solvent by acetone into the aqueous solution and the pesticides are transferred into the extraction solvent. After extraction, phase separation is performed by centrifugation and the enriched analytes in the sedimented phase are determined. The influence of different parameters affecting the extraction efficiency was investigated and optimized. Under the optimized extraction conditions, enrichment factor for the analytes was obtained in the range of 279-428 with extraction recovery of 56-86%. Limits of detection and quantification were obtained in the ranges of 0.32-1.2 and 1.1-4.0 ng g-1, respectively. Relative standard deviations were ≤ 7% for intra- (n = 6) and inter-day (n = 5) precisions calculated at two concentrations of 10 and 50 ng g-1 of each analyte. Finally, some honey samples were effectively analyzed by the proposed method and diazinon was determined at ng g-1 concentration in one sample.

Farajzadeh MA ，Abbaspour M ，Kazemian R 《-》

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 ... -  《-》

Synthesis and characterization of phosphocholine chloride-based three-component deep eutectic solvent: application in dispersive liquid-liquid microextraction for determination of organothiophosphate pesticides.

A new type of deep eutectic solvent based on three components using phosphate salts has been synthesized, characterized, and applied in the extraction of eight organothiophosphate pesticides from honey samples. In this study, the deep eutectic solvent was prepared from phosphocholine choline chloride as a hydrogen bond acceptor and dichloroacetic acid and decanoic acid as hydrogen bond donors. The method consisted of two steps in which initially the analytes were extracted from the samples into a water-miscible organic solvent. In the second step, the extracted phase was mixed with the prepared deep eutectic solvent and the mixture was used in the following dispersive liquid-liquid microextraction method. The method was validated under optimal conditions, and it was found that it has low limits of detection (0.05-0.10 ng g-1 ) and quantification (0.19-0.36 ng g-1 ), good linearity (r2  ≥ 0.994), broad linearity (0.36-1000 ng g-1 ), and satisfactory repeatability (relative standard deviation ≤10% for intra- (n = 6) and inter-day (n = 4) precisions at a concentration of 2 ng g-1 of each analyte). The proposed method was applied in different honey samples, and malathion was found at a concentration of 29 ng g-1 in one sample. © 2019 Society of Chemical Industry.

Mokhtari N ，Torbati M ，Farajzadeh MA ，Afshar Mogaddam MR ... -  《-》

Preparation of a new three-component deep eutectic solvent and its use as an extraction solvent in dispersive liquid-liquid microextraction of pesticides in green tea and herbal distillates.

A new solvent, deep eutectic solvent, in which there is growing interest, has been prepared and used as an extraction solvent in the dispersive liquid-liquid method of microextraction. To prepare the solvent, dichloroacetic acid, l-menthol, and n-butanol are mixed at a molar ratio of 4:1:1 and the deep eutectic solvent is formed after heating. Then a dispersive liquid-liquid microextraction method using the prepared solvent is used for the extraction and preconcentration of some pesticides from an aqueous sample. To carry out the procedure, the deep eutectic solvent is mixed with methanol and rapidly injected by a syringe into the aqueous sample containing the analytes. After centrifuging, an aliquot of the sedimented phase is injected into the gas chromatograph. The influence of several variables on the extraction efficiency was investigated and optimized. Extraction recoveries and enrichment factors were obtained in the ranges of 53-86% and 1760-2853, respectively. The intra- (n = 6) and inter-day (n = 5) precision of the method was satisfactory, with relative standard deviations ≤ 7% obtained at two concentrations of 10 and 50 μg L-1 of each analyte. Moreover, detection and quantification limits for the target analytes were obtained in the ranges of 0.11-0.23 and 0.38-0.74 μg L-1 , respectively. Different samples, including green tea, rose water, lemon balm, mint, and pussy willow distillates were analyzed successfully using the method that was developed, and chlorpyrifos was found in rose water at a concentration of 17 ± 1 μg L-1 (n = 3). © 2019 Society of Chemical Industry.

Farajzadeh MA ，Abbaspour M ，Kazemian R ，Afshar Mogaddam MR ... -  《-》

Combination of dispersive solid phase extraction with solidification organic drop-dispersive liquid-liquid microextraction based on deep eutectic solvent for extraction of organophosphorous pesticides from edible oil samples.

A dispersive solid phase extraction method was combined with deep eutectic solvent-based solidification of floating organic drop-dispersive liquid-liquid microextraction and used for the extraction/preconcentration of some organophosphorus pesticides residues from edible oil samples. The extracted analytes were quantified with gas chromatography-nitrogen phosphorous detector. In this procedure, the sample lipids are saponified with a sodium hydroxide solution and then the analytes are adsorbed onto a primary secondary amine sorbent. After that the analytes are desorbed with acetone as an elution/dispersive solvent and mixed with choline chloride: 3,3-dimethyl butyric acid deep eutectic solvent and the mixture is rapidly dispersed into deionized water. Then, the obtained cloudy solution is centrifuged and placed into an ice bath. The extraction solvent is solidified on the top of the solution. Finally, it is removed and dissolved in acetonitrile, and 1 µL of the solution is injected into the separation system. Validation of the method showed that limits of detection and quantification were in the ranges of 0.06-0.24 and 0.20-0.56 ng mL-1, respectively. Enrichment factors and extraction recoveries of the analytes ranged from 170-192 and 68-77%, respectively. The method had an acceptable precision with relative standard deviations less than ≤9.2% for intra- (n=6) and inter-day (n=6) precisions at four concentrations (3, 10, 50, and 250 ng mL-1, each analyte). Finally the method was used for determination of the analytes in five edible oil samples.

Zahiri E ，Khandaghi J ，Farajzadeh MA ，Afshar Mogaddam MR ... -  《-》