scholarly journals Deep eutectic solvent-based emulsification liquid–liquid microextraction for the analysis of phenoxy acid herbicides in paddy field water samples

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Nur ‘An Nisaa Mohamad Yusoff ◽  
Nurul Yani Rahim ◽  
Rania Edrees Adam Mohammad ◽  
Noorfatimah Yahaya ◽  
Mazidatulakmam Miskam

An emulsification liquid–liquid microextraction (ELLME) method was successfully developed using phenolic-based deep eutectic solvent (DES) as an extraction solvent for the determination of phenoxy acid herbicides, 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 2-methyl-4-chlorophenoxyacetic acid (MCPA) in environmental water samples. Five different phenolics-based DESs were successfully synthesized by using phenol (DES 1), 2-chlorophenol (DES 2), 3-chlorophenol (DES 3), 4-chlorophenol (DES 4) and 3,4-dichlorophenol (DES 6) as the hydrogen-bond donor (HBD) and choline chloride as the hydrogen-bond acceptor (HBA). The DESs were mixed at 1 : 2 ratio. A homogeneous solution (clear solution) was observed upon the completion of successful synthesis. The synthesized DESs were characterized by using Fourier transform infrared and nuclear magnetic resonance (NMR). Under optimum ELLME conditions (50 µl of DES 2 as extraction solvent; 100 µl of THF as emulsifier solvent; pH 2; extraction time 5 min), enrichment factor obtained for dicamba and MCPA were 43.1 and 59.7, respectively. The limit of detection and limit of quantification obtained for dicamba were 1.66 and 5.03 µg l −1 , respectively, meanwhile for MCPA were 1.69 and 5.12 µg l −1 , respectively. The developed ELLME-DES method was applied on paddy field water samples, with extraction recoveries in the range of 79–91% for dicamba and 82–96% for MCPA.

2020 ◽  
Vol 58 (9) ◽  
pp. 880-886
Author(s):  
Xiao Li ◽  
Tao Yuan ◽  
Ting Zhao ◽  
Xiaomei Wu ◽  
Yaling Yang

Abstract An environmentally friendly method for the determination of testosterone and methyltestosterone by acid–base-induced deep eutectic solvents liquid–liquid microextraction (DES-ABLLME) combining with high-performance liquid chromatography was established. The deep eutectic solvent (DES) consisting of menthol:lauric acid:decanoic acid (3:1:1) can act as both hydrogen bond donor and hydrogen bond acceptor. In this approach, ammonia solution (NH3•H2O) is used as an emulsifier to react with DESs in the extraction process to generate salt and form milky white solution, achieving high extraction efficiency. Hydrochloric acid was used as a phase separator to change the emulsification state and promote the separation of extraction agent from water phase. A series of parameters were optimized including the volume of DES and the emulsifying agent, glucose concentration as well as hydrochloric acid volume. The method was linear in the range 0.5–100 μg mL−1 with a correlation coefficient (R) of 0.9999, and the limits of detection were 0.067 and 0.2 μg mL−1 for testosterone and methyltestosterone, respectively. This method was applied to analyze testosterone and methyltestosterone in milk samples, and the recoveries were between 89.2 and 108.2%.


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2785 ◽  
Author(s):  
Rawikan Kachangoon ◽  
Jitlada Vichapong ◽  
Yanawath Santaladchaiyakit ◽  
Rodjana Burakham ◽  
Supalax Srijaranai

A green, simple and sensitive hydrophobic DES-based dispersive liquid–liquid microextraction coupled with high-performance liquid chromatography (HPLC) was developed for the analysis of neonicotinoid insecticide residues in various samples. A hydrophobic deep eutectic solvent (DES) was synthesized using decanoic acid as a hydrogen bond donor and tetrabutylammonium bromide (TBABr) as a hydrogen bond-acceptor. DESs were synthesized and characterized by Fourier transform-infrared (FTIR) spectroscopy. Two disperser solvents were substituted with surfactants and acetonitrile, which could afford more effective emulsification and make the extraction relatively greener. The hydrophobic DES extraction phase occurred 10 min after centrifugation, being easy to be collected for analysis. Several parameters were investigated and optimized. Under the optimum condition, the calibration curve of this method was linear in the range of 0.003–1.0-µg·mL−1, with a correlation coefficient (R2) higher than 0.99 and a good repeatability, with the relative standard deviations (RSDs) were less than 5.00%. The limits of detection were in the range of 0.001–0.003 µg·mL−1; the limits of quantitation were in the range of 0.003–0.009 µg·mL·mL−1. Finally, the presented method was implemented to determine the neonicotinoid insecticide residues in water, soil, egg yolk samples and acceptable recoveries were obtained.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1599
Author(s):  
Jinke Liu ◽  
Letian Qi ◽  
Guihua Yang ◽  
Yu Xue ◽  
Ming He ◽  
...  

A novel choline-based deep eutectic solvent (DES) with low halogen content—namely choline lactate-lactic acid (CLL)—was synthesized by replacing the chloride anion with lactate anion in choline chloride-lactic acid (CCL). CLL and CCL treatments were conducted at 140 °C for 12 h with hydrogen bond acceptor/hydrogen bond donor =1/10, thereafter composition analysis and characterizations of the lignin extracted by DES treatment (DES lignin) and the solid residue were carried out. The proposed low halogen content DES presented an improved lignin extraction efficiency. The CLL treatment extracted 90.13% of initial lignin from poplar, while CCL extracted 86.02%. In addition, the CLL treatment also provided DES lignin with an improved purity (91.17%), lower molecular weight (Mw/Mn=1805/971 g/mol) and more concentrated distribution (polydispersity index=1.86). The efficient lignin extraction was mainly ascribed to the cleavage of β-O-4 bonds in lignin macromolecule, especially in the guaiacyl units, thereby breaking them into smaller molecules, facilitating the lignin extraction. The replacement of chloride anion allowed CLL acting as a more efficient DES to interact with lignin macromolecules, thus providing lignin with higher uniformity and suitable molecular weight. The low halogen content DES system proposed in present work could benefit the fractionation of biomass, improve the valorization of lignin compounds and facilitate industrial process in the downstream.


2017 ◽  
Author(s):  
◽  
Maryam Al Ameri

In this study, green solvent-based pretreatment was developed for improving the conversion of switchgrass to acetoin. Deep eutectic solvents (DESs), comprising choline chloride (ChCl) as a hydrogen-bond acceptor (HBA) and various chemical as a hydrogen-bond donor (HBD), were used to pretreat switchgrass. Different HBD groups, including polyalcohol, amid, diazole, and carboxylic acid, were used to synthesize DESs. The DESs using ChCl-formic acid and ChCl-lactic acid-acetic acid showed excellent performance in enhancing switchgrass digestibility. The obtained hydrolysate was successfully detoxified by using overliming detoxification, which was further used for acetoin fermentation by Bacillus licheniformis (NRRL B-642). The yield and titer of the produced acetoin were 0.377 g/g and 19.6 g/L, respectively. Our research demonstrates that DES pretreatment is an effective method for reducing biomass recalcitrance and improving the conversion of biomass into chemicals.


2018 ◽  
Vol 19 (3) ◽  
pp. 864-870 ◽  
Author(s):  
Cennet Karadaş ◽  
Derya Kara

Abstract In this paper, a novel emulsification liquid–liquid microextraction method based on deep eutectic solvents (DESs) for the preconcentration of lead from water samples and its determination by flame atomic absorption spectrometry is described. Purpurin was used as complexing ligand and the Pb(II)-purpurin complexes were extracted and preconcentrated from the aqueous phase using a choline chloride/2-chlorophenol (at a 1:2 molar ratio) based DES as a water-miscible extraction solvent and tetrahydrofuran as an emulsifier solvent. Some analytical parameters affecting the extraction yield were investigated and optimized. Using a 20 mL aqueous sample, the limit of detection and preconcentration factor of the method were 5.93 μg L−1 and 20, respectively. The accuracy of the method was assessed through the analysis of certified reference surface water (SPS-SW2 Batch 127) and spiked water samples. The certified and obtained values were statistically in good agreement at 95% confidence level. The recovery values of spiked water samples were between 102% and 105%.


2016 ◽  
Vol 18 (27) ◽  
pp. 18145-18160 ◽  
Author(s):  
Claire R. Ashworth ◽  
Richard P. Matthews ◽  
Tom Welton ◽  
Patricia A. Hunt

Computational analysis indicates flexibility and diversity in the hydrogen bonding, but limited charge delocalisation, within the choline chloride–urea eutectic.


2021 ◽  
Author(s):  
Huazi Wang ◽  
Qinqin Xu ◽  
Jinglong Jiao ◽  
Hai Wu

A solidified floating organic drop-dispersive liquid-liquid microextraction (SFOD-DLLME) was established for extraction of four benzophenone-ultraviolet filters (BP-UV filters) from water samples using a fatty acid deep eutectic solvent (DES) as...


2020 ◽  
Vol 15 (2) ◽  
pp. 1934578X1990070 ◽  
Author(s):  
Weida Zhang ◽  
Shaobo Cheng ◽  
Xiaona Zhai ◽  
Junshe Sun ◽  
Xuefang Hu ◽  
...  

Deep eutectic solvents (DESs) were proposed for the extraction of polysaccharides from Poria cocos (PCPs). Six types of DESs were prepared, and the DES composed of choline chloride and oxalic acid was proved to be suitable. Based on the results of single-factor test, the Box-Behnken experimental design with response surface methodology was carried out, giving the optimal extraction conditions including mole ratio of 1:2 (choline chloride:oxalic acid) and extraction 15 minutes at 100°C. Under the optimal extraction conditions, the extraction yield (46.24% ± 0.13%) was 8.6 times higher than that of hot water. The reusability of DES was demonstrated by a 6-run test, and an extraction yield of PCP was 38.40% ± 0.23% after reusing for 6 times without adding any additional chemicals. Moreover, molecular weight distributions of the resulting PCP were analyzed, and then mainly distributed in the range of 753 to 3578 g/mol. Therefore, DESs were proved to be an excellent extraction solvent alternative to the extraction of PCP.


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