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Rutin from Ginkgo biloba L. leaves (78.63 mg g−1) was mildly and effectively extracted using an ultrasound-assisted process with tailor-designed natural deep eutectic solvent-based cellulose polymer adsorbents. The physicochemical properties and structural characteristics of the synthesized natural deep eutectic solvent-modified cellulose polymers were examined by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, and elemental analysis. The ultrasound-assisted extraction conditions were optimized using a response surface methodology (extraction time, 40 min; sample to solvent ratio, 1:29 g/mL; extraction temperature, 81 °C; and ultrasound frequency, 180 W). The ultrasound-assisted extraction method is environmentally friendly and allows the simple and easy recovery of components. In addition, this approach is effective for the extraction, separation, and detection of rutin. These findings might promote the applications of rutin from G. biloba L. leaves in several fields. [ABSTRACT FROM AUTHOR]

Growing concerns related to antibiotic residues in environmental water have encouraged the development of rapid, sensitive, and accurate analytical methods. Single‐drop microextraction has been recognized as an efficient approach for the isolation and preconcentration of several analytes from a complex sample matrix. Thus, single‐drop microextraction techniques are cost‐effective and less harmful to the environment, subscribing to green analytical chemistry principles. Herein, an overview and the current advances in single‐drop microextraction for the determination of antibiotics in environmental water are presented were included. In particular, two main approaches used to perform single‐drop microextraction (direct immersion‐single‐drop microextraction and headspace‐single‐drop microextraction) are reviewed. Furthermore, the impressive analytical features and future perspectives of single‐drop microextraction are discussed in this review. [ABSTRACT FROM AUTHOR]

Eight deep eutectic solvents composed of choline chloride and various acids were used to synthesize chitosan derivatives. All acidic deep eutectic solvents resulted in high transmittance and stable chitosan derivatives under the appropriate reaction conditions. Choline chloride–oleic acid–chitosan provided the best performance and was used for the ultrasound-assisted extraction of rutin, quercetin, and isorhamnetin from sea buckthorn (Hippophae rhamnoides L.) leaves coupled with reversed-phase high-performance liquid chromatography (RP-HPLC). The extraction provided recoveries of 107.5 ± 0.16 rutin, 30.22 ± 0.37 quercetin, and 43.5 ± 0.22 isorhamnetin mg g−1 dry powder using the optimal conditions at 41 °C, solid/solvent ratio of 1:24 g mL−1, and six adsorption/desorption cycles. The linear range was from 1.0 to 1000.0 µg mL−1 and the limits of detection (LODs) for rutin, quercetin, and isorhamnetin were 0.12, 0.16, and 0.23 µg g−1, respectively. The results showed that sea buckthorn (H. rhamnoides L.) leaves, a food industry by-product, may be used as an inexpensive source of flavonoids. [ABSTRACT FROM AUTHOR]

β‐Sitosterol is a major bioactive constituent in plants with potent anticancer effects against many human cancer cells, but its bioavailability and therapeutic efficacy are limited by its poor solubility in water. In this study, C6‐imidazole chitosan, C6‐1‐methylimidazole chitosan, C6‐1‐ethylimidazole chitosan, C6‐1‐vinylimidazole chitosan, C6‐1‐allylimidazole chitosan, and C6‐1‐butylimidazole chitosan were prepared to extract β‐sitosterol from edible oil samples via ultrasonic‐assisted solid liquid extraction. The structures and properties of the newly synthesized products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and elemental analysis. The extraction abilities of the derivatives were tested in the experiment with high‐performance liquid chromatography (limit of detection 0.21 μg/g and limit of quantification 0.67 μg/g), and the % relative standard deviation (<3.25%) and recovery values of the prepared chitosan derivatives toward β‐sitosterol (average: 100.20%) were acceptable. The spiked interday and intraday recoveries of β‐sitosterol were 102.60 ± 2.78 and 103.90 ± 3.04%, respectively. The actual amounts of β‐sitosterol extracted from three real samples using C6‐imidazole chitosan according to the solid phase extraction method were 3302.40, 901.70, and 2045.60 mg/kg for corn oil, olive oil, and pea oil, respectively. [ABSTRACT FROM AUTHOR]

A reliable and efficient method for the simultaneous extraction and determination of antibiotics of ciprofloxacin and levofloxacin from milk was developed with solid phase extraction based on tailored adsorbent materials of deep eutectic solvents modified phenolic resin (DES-R-SPE). Six types of polyhydric alcohol-based hydrophilic DESs were prepared to modify the phenolic resin with the compositions of 3-aminophenol as a functional monomer, glyoxylic acid as a crosslinker, and polyethylene glycol 6000 as a porogen. And the prepared DES-Rs showed better extraction capacities for the target analytes than the unmodified phenolic resin because of more hydrogen bonding and electrostatic interactions supplied by DESs. The choline chloride-glycerol–based resin (DES1-R) with the highest adsorption amounts was selected and the adsorption behavior of it was studied with static adsorption and the dynamic adsorption performance; the adsorption process followed Freundlich isotherm (R2 ≥ 0.9337) and pseudo-second-order (R2 ≥ 0.9951). The present DES1-R-SPE method showed good linear range from 0.5 to100 μg mL−1 (R2 ≥ 0.9998), good recoveries of spiked milk samples (LEV, 96.7%; CIP, 101.5%), and satisfied repeatability for intra-day and inter-day (LEV, RSD≤5.4%; CIP, RSD≤4.6%). [ABSTRACT FROM AUTHOR]

Ultrasonic-assisted extraction methods have been applied in many fields in recent decades. In this study, chlorogenic acid was isolated from capillary artemisia ultrasonically using the designed poly (natural deep eutectic solvents-ethylene glycol dimethacrylate) cellulose. The actual quantity of chlorogenic acid extracted was 62.83 mg g−1 dry powder using the following optimal conditions: raw material to liquid ratio of 1:40 g mL−1, extraction temperature of 80 °C, ultrasonic power of 160 W, and extraction time of 40 min. The limit of detection for chlorogenic acid in capillary artemisia was 0.14 µg mL−1, and the intraday and interday precision values as the relative standard deviation (n = 6) after spiking with 5, 100, and 500 µg mL−1 were both less than 4.21%. This paper reports an effective method that provides facile operation, is low cost, and has excellent selectivity for chlorogenic acid in capillary artemisia. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) which possess hydrophobicity were synthesized from various carboxylic acid or fatty acids and menthol to remove bisphenol A, a micropollutant present in water-based environments, via liquid–liquid extraction. The bisphenol A concentration was measured quantitatively by ultraviolet-visible spectroscopy. The structure and properties of the DES were examined by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy, and the interaction of the cephalic compound was investigated. The menthol–propionic acid and menthol–formic acid DES provided the satisfactory extraction performance and several parameters, including the type and volume, stirring speed, and time of the extraction procedure, were optimized. Excellent recovery rates of 98.2%–99.0% for bisphenol A were obtained under the optimized conditions. [ABSTRACT FROM AUTHOR]

A visual, rapid, and sensitive micro‐solid phase extraction method was developed for the detection of p‐hydroxybenzoic acid using molecularly imprinted chitosan microspheres based on deep eutectic solvents, both as a functional monomer and template. The parameters were optimized by using the response surface methodology strategy. The extraction capacity of p‐hydroxybenzoic acid from pear rind under the optimized conditions using response surface methodology was 46.32 mg/g, when the pH of the extract solution (2), extraction time (35 min), extraction temperature (30°C), and adsorbent dosage (2 mg). The molecularly imprinted chitosan microspheres produced higher selectivity and extraction capacity than the traditional materials. [ABSTRACT FROM AUTHOR]

A deep eutectic solvent (DES) was prepared from choline chloride (ChCl) and methacrylic acid (MAA) and used as an eco-friendly surfactant and functional monomer. The process of producing DES and its free energy of formation (ΔG = −37.225 kcal mol−1) were evaluated theoretically by density-functional theory. The designed DES (ChCl–MAA) was introduced as a novel eco-friendly functional monomer (MAA as the control group) during the preparation of levofloxacin-imprinted nanoparticles (LINs) based on molecular imprinting technology. The nanoparticles were characterized using a range of techniques. The nanoparticles were applied as an adsorbing material to the selective removal of levofloxacin from environmental waste water. The selective removal and adsorption capacity of the adsorbing material were evaluated by high-performance liquid chromatography. Based on the introduction of DES, DES–LINs had better adsorption capacity for levofloxacin than common LINs. This method had the simple operation, rapid adsorption and efficient decontamination. [ABSTRACT FROM AUTHOR]

Novel molecularly imprinted chitosan microspheres were prepared on the surface of magnetic graphene oxide, with deep eutectic solvents both as a functional monomer and template. The prepared molecularly imprinted chitosan microspheres‐magnetic graphene oxide was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, Brunauer‐Emmett‐Teller surface area, thermogravimetric analysis were subsequently combined with solid‐phase micro‐extraction for simultaneous separation and enrichment of the extraction of chlorophenols from environmental water. Factors affecting the extraction efficiency of chlorophenols were optimized using response surface methodology. The actual extraction capacities under the optimal conditions (liquid to solid ratio = 3, cycles of adsorption/desorption = 5, 40°C extraction temperature, and extraction time for 35 min) were 86.90 mg/g. Compared to the traditional materials, the molecularly imprinted chitosan microspheres‐magnetic graphene oxide produced higher selectivity and extraction capacity. [ABSTRACT FROM AUTHOR]

Air assisted dispersive liquid–liquid microextraction (AA-DLLME) using hydrophilic–hydrophobic deep eutectic solvents (DES) was developed for the simultaneous isolation of monosaccharides and amino acids with wide ranges of polarities from kelp using high performance liquid chromatography (HPLC). A response surface methodology (RSM) on a Box–Behnken design (BBD) model was employed to identify the optimal extraction parameters. Air assisted dispersive liquid-phase microextraction performed using the optimum deep eutectic solvent system, five push–pull cycles, a ratio of solid to liquid equal to 3 mg·mL−1, 10% (w/v) NaCl, and a centrifugation time of 6 min provided the best analytical performance. The optimal extracted concentrations of d-(+)-galactose, l-(-)-fucose, dl-tyrosine, and dl-valine in kelp were 16.7 ± 0.2, 8.6 ± 0.2, 2.6 ± 0.1, and 1.6 ± 0.1 mg·g−1, respectively. The method recoveries for d-(+)-galactose, l-(-)-fucose, dl-tyrosine, and dl-tyrosine were from 87 to 102%, 84 to 103%, 87 to 104%, and 85 to 103%. The relative standard deviations (RSDs) (n = 4) for the intra-day and inter-day determinations were <6.17%. [ABSTRACT FROM AUTHOR]

Hexagonal boron nitride (h-BN) is introduced as a 2D scaffold during the preparation of molecularly imprinted polymers (MIPs). The MIPs were prepared from deep eutectic solvents (DES) or from DES containing h-BN, crosslinking agent (ethylene glycoldimethacrylate), initiator (AIBN), porogen (methanol), and template (quercetin). The recognition site of the monomer is protected by the hydrogen bond of the DES before the MIP is polymerized. The formation of the final MIP was analyzed theoretically using density-functional theory. The nanoparticles were characterized by scanning electron microscopy, nitrogen sorption analysis, thermogravimetry and Fourier transform infrared spectroscopy. The introduction of h-BN resulted in an increase in the surface area of the nanoparticles. They were applied as a solid phase extraction sorbent for the extraction of flavonoids (specifically of quercetin, isorhamnetin and kaempferol) from Ginkgo biloba leaves. Following extraction with ethanol, they were quantified by HPLC. The new sorbent has distinctly improved recognition capability for flavonoids compared to conventional MIP nanoparticles. [ABSTRACT FROM AUTHOR]

Beta-carotene is a carotenoid with strong antioxidant activity that has been used in many areas and attracted significant attention. Among the articles reported, however, there are few examples of the convenient and eco-friendly use of magnetic chitosan biopolymers to extract beta-carotene. This paper reports the ultrasonic-assisted solid phase extraction of beta-carotene. The beta-carotene in carrot samples was extracted using synthesized magnetic chitosan beta-cyclodextrin biopolymers prior to high-performance liquid chromatography (HPLC) detection. Under the optimal conditions, the beta-carotene content of carrot was found to be 41.06 ± 0.02 μg/g. This newly developed method using magnetic chitosan cyclodextrin biopolymers is a promising method for the ultrasonic-assisted solid phase extraction of carotenoids from vegetables because the procedure is facile and rapid and the magnetic biopolymers can be removed using simple process. [ABSTRACT FROM AUTHOR]

Chitosan derivatives have been studied widely, but poor solubility in water restricts their applications. In this study, four types of amine‐based chitosan derivatives were prepared and modified further with beta‐cyclodextrin. The sequential microextraction of catechins ((+)‐catechin and (−)‐epigallocatechin gallate) from green tea powder by an optimized solid‐phase extraction method using these four derivatives was investigated. The optimal conditions for the extraction of catechins were 60°C for a 40 min extraction period. The purity and amount of each catechin were determined by high‐performance liquid chromatography. The different amines strengthened the extraction capacity of chitosan. Among the four types of amines, ethylene diamine grafted chitosan beta‐cyclodextrin had the highest extraction capacity to catechins. Therefore, this material was used in the extraction assay, and the standard curves of (+)‐catechin and (−)‐epigallocatechin gallate were linear over the concentration range, 0.25–500 µg/mL, after assaying five data points in duplicate. Solid‐phase extraction with the amino‐based chitosan beta‐cyclodextrin system is a new application of chitosan, which has potential applications in the extraction of bioactive compounds from plant materials or the removal of different impurities from specific extracts. [ABSTRACT FROM AUTHOR]

Isoflavone exhibits estrogen-like structure and activity and has various physiological and pharmacological functions, such as anticancer, antioxidant, and anti-inflammatory. In this study, several deep eutectic solvents (DESs) were synthesized and used as mobile phase additives to optimize the analytical conditions of five isoflavones. The DES composed of choline chloride:citric acid (molar ratio 1:1) was the most effective mobile phase additive with reduced peak tailing, improved peak shape, and increased number of theoretical plates. The effectiveness of the DES highlights its potential as a mobile phase additive. The optimal high-performance liquid chromatography (HPLC) conditions for the isoflavones were determined by the Intelligent HPLC simulator. The optimal conditions for gradient elution were water (A): acetonitrile (B) for 0 min, 25% B; 15 min, 25% B; 17 min, 35% B; and 50 min, 35% B. This approach provided excellent linearity (0.5 to 500 μg/mL, R2 ≥ 0.9991), limits of detection (0.024 to 0.109 μg/mL), limits of quantification (0.079 to 0.363 μg/mL), and precision (1.74 to 4.80%). [ABSTRACT FROM AUTHOR]

A novel method was developed to simultaneously determine the ciprofloxacin and levofloxacin levels in human urine using an ionic‐liquid‐based, dual‐molecularly imprinted polymer‐coated graphene oxide solid‐phase extraction monolithic column coupled with high‐performance liquid chromatography. The molecularly imprinted monolithic column was prepared using ciprofloxacin and levofloxacin as templates, 1‐vinyl‐3‐ethylimidazolium bromide as the functional monomer, and graphene oxide as the core material. The resulting imprinted monoliths were characterized by scanning electron microscopy and fourier transform‐infrared spectroscopy. The efficiency and capacity of the ionic‐liquid‐based imprinted monolithic column were investigated by varying the synthesis conditions (ciprofloxacin/levofloxacin ratio and template/functional monomer/cross‐linker ratio). The solid‐phase extraction process was optimized by changing the washing and eluting conditions. The results suggested that the proposed ionic‐liquid‐based molecularly imprinted solid‐phase extraction monolithic‐high‐performance liquid chromatography method could separate ciprofloxacin and levofloxacin efficiently and simultaneously from human urine. The mean recoveries of ciprofloxacin and levofloxacin ranged from 89.2 to 93.8 and 86.7 to 94.6%, respectively. The intra‐ and interday relative standard deviation ranged from 0.9 to 3.2 and 0.8 to 2.9%, respectively. Under the optimized conditions, the recoveries of ciprofloxacin and levofloxacin were more than 93.8%. [ABSTRACT FROM AUTHOR]

A ternary deep eutectic solvent (TDES) was used as both template and functional monomer in the synthesis of TDES-based molecularly imprinted polymers (TDES-MIPs). A meticulous miniaturized solid-phase microextraction (mini-SPME) method followed by high-performance liquid chromatography (HPLC) were used for the optimal speciation of 3,4-dihydroxybenzoic acid (3,4-DHBA) in the needle of a syringe system with response surface methodology (RSM). Under the optimal conditions for the determination of 3,4-DHBA (amount of adsorbent (2 mg), sample volume (1 mL), cycles for adsorption and desorption (6)), the actual extraction amount was 8.46 μg g−1. The limits of detection (LODs, S/N = 3) for 3,4-DHBA in Ilex chinensis Sims were 0.26-0.31 μg mL−1, and the intra-day and inter-day precision (relative standard deviations, n = 4) after spiking with 5 μg mL−1, 100 μg mL−1, and 200 μg mL−1 were both less than 4.21%. The meticulous method (TDES-MIP-mini-SPME) combined with RSM offers a significant advance over existing methods, because of the meticulous operation and excellent selectivity of 3,4-DHBA from complex samples.ᅟ [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Controllable thermo-responsive T-MIR preparation via hydrophilic thermo-responsive monomer synergy in water solution. • The details of possible mechanism of zipper-like controllable adsorption/release of T-MIR for target. • A DSPE method was developed for selective enrichment of alkaloids by T-MIR. Abstract A novel controllable hydrophilic thermo-responsive molecularly imprinted resin (T-MIR) with a switchable zipper-like architecture was synthesized in the aqueous phase and applied to the selective recognition and extraction of alkaloids by positive temperature regulation. In this synthesis process of T-MIR, 2-acrylamide-2- methylpropanesulfonic acid (AMPS) and acrylamide (AAm) were coupled as zipper-like thermo-responsive monomers, resorcinol, and melamine as hydrophilic monomers, formaldehyde as a cross-linker, and berberine chloride (BerbC) as the template. The resulting T-MIR achieved the controlled rebinding and release of BerbC from temperature stimuli (25–45 °C) and the adsorption process followed the Langmuir isotherm (R2>0.99856) and pseudo-second-order kinetic model (R2>0.98138). The highest theory adsorption ability (33.44 mg/g) and recognition ability (imprinting factor: 4.71) of T-MIR was activated between poly(AMPS) and poly(AAm) in the zipper-like architecture at 35 °C. T-MIR was then applied to the selective recognition alkaloids by dispersive solid phase extraction. The limit of detection and limit of quantitation of the method were less than 0.025 mg/L and 0.082 mg/mL, respectively. The recoveries of the proposed method at three spiked levels were 96.8–100.8%, with a relative standard deviation of less than 4.8%. In contrast to previous thermo-responsive materials, this switchable zipper-like hydrophilic T-MIR with good adsorption, specificity recognition, and excellent temperature controllable properties provides a unique alternative to the selective recognition and controlled rebind-release alkaloids by the temperature signal. [ABSTRACT FROM AUTHOR]

Abstract: Three types of choline chloride based deep eutectic solvents were prepared and used to modify magnetic chitosan. The adsorption capacity of the three deep‐eutectic‐solvent‐modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin for removing methyl orange from wastewater was examined. The different deep eutectic solvents were used to strengthen the adsorption capacity of magnetic chitosan. Deep‐eutectic‐solvent‐modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin materials were characterized by Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller surface area measurements. Among the three deep eutectic solvents, choline chloride/glycerol (1:2) modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin showed the highest adsorption capacity to methyl orange. Therefore, choline chloride/glycerol (1:3, 1:4, 1:5, 1:6) deep eutectic solvents were prepared for the assay, and choline chloride/glycerol‐modified magnetic chitosan/carboxymethyl‐β‐cyclodextrin prepared with choline chloride/glycerol (1:3) (volume: 40 μg, contact time: 30 min, and pH: 6) had the best adsorption capacity over the concentration range of 10–200 μg/mL. [ABSTRACT FROM AUTHOR]

Abstract: A hydrophobic ionic liquid modified thermoresponsive molecularly imprinted monolith was synthesized using N‐isopropylacrylamide as a thermoresponsive monomer and a long‐chain hydrophobic ionic liquid as an auxiliary modification monomer. The ionic‐liquid‐modified thermoresponsive molecularly imprinted polymer was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. When the column temperature was 50°C, the synthesized monolithic column was successfully applied to the selective separation of homologue tanshinones within 7 min and eluted only by water (mobile phase) (theoretical plates more than 1.00 × 105 per meter). The negative Gibbs free energy (≤–2.37) values showed that the transfer of the tanshinones from the mobile phase to the stationary phase on this monolithic column was a thermodynamically spontaneous process. Good linearity of the five tanshinones by thermoresponsive monolith was obtained in the range of 0.100–25.0 μg/mL. The limit of detection (S/N = 3) and limit of quantitation (S/N = 10) were less than 0.0390 and 0.0630 μg/mL, respectively, with a relative standard deviation of <4.8%. In this proposed thermoresponsive chromatography method, the separation of homologue analytes can be achieved by changing the column temperature, and the use of water as the mobile phase would decrease the economic cost and organic pollution. [ABSTRACT FROM AUTHOR]

Abstract: Ternary deep eutectic solvent magnetic molecularly imprinted polymers grafted on silica were developed for the selective recognition and separation of theophylline, theobromine, (+)‐catechin hydrate, and caffeic acid from green tea through dispersive magnetic solid‐phase microextraction. A new ternary deep eutectic solvent was adopted as a functional monomer. The materials obtained were characterized by FTIR spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, NMR spectroscopy, and powder X‐ray diffraction. The practical recovery of the theophylline, theobromine, (+)‐catechin hydrate, and caffeic acid isolated with ternary deep eutectic solvent magnetic molecularly imprinted polymers in green tea were 91.82, 92.13, 89.96, and 90.73%, respectively, and the actual amounts extracted were 5.82, 4.32, 18.36, and 3.69 mg/g, respectively. The new method involving the novel material coupled with dispersive magnetic solid‐phase microextraction showed outstanding recognition, selectivity and excellent magnetism, providing a new perspective for the separation of bioactive compounds. [ABSTRACT FROM AUTHOR]

A type of magnetic ionic liquid based molecularly imprinted polymer coated on SiO 2 (Fe 3 O 4 @SiO 2 @IL-MIPs) was prepared with 1-vinyl-3-ethylimidazole ionic liquid as functional monomer, and 1,4-butane-3,3′-bis-1-ethylimidazole ionic liquid as cross linker, 4-Chlorophenol as template was successfully applied as a selective adsorbent for selective extraction of 5 chlorophenols in seawater samples by using the magnetic solid-phase extraction (MSPE) method. 11 types of Fe 3 O 4 @SiO 2 @IL-MIPs were synthesized and investigated for their different compositions of functional monomer (such as [C 2 min][Br], [C 2 min][BF 4 ], [C 2 min][PF 6 ], acrylamide, methacrylic acid and 4-vinyl pyridine) and cross-linker (such as [C 4 min 2 ][Br], [C 4 min 2 ][BF 4 ], [C 4 min 2 ][PF 6 ], divinylbenzene, and ethylene glycol dimethacrylate), respectively. The [C 2 min][BF 4 ] and [C 4 min 2 ][PF 6 ] based Fe 3 O 4 @SiO 2 @IL-MIP with the highest extraction efficiencies was applied to the optimization experiment of MSPE process (including extraction time, adsorbent mass and desorption solvents). Good linearity was obtained with correlation coefficients (R 2 ) over 0.9990 and the relative standard deviations for the intra-day and inter-day determination were less than 3.10% with the extraction recoveries ranged from 85.0% to 98.4%. The results indicated that the proposed Fe 3 O 4 @SiO 2 @IL-MIPs possesses great identification and adsorption properties, and could be used as a good sorbent for selective extraction of CPs in environment waters. [ABSTRACT FROM AUTHOR]

Size exclusion chromatography (SEC) was developed for the separation of large molecules, such as proteins, polymer, peptides, nucleic acid, and polysaccharides. In this study, ionic liquid-modified silica was synthesized to examine the retention behavior of polysaccharides, such as dextran, fucoidan, alginic acid, and laminarin. Commercial SEC column separated large molecules according to their molecular size. However, Ionic liquid-modified silica is expected to retention behavior by the functional group between ionic liquid-modified silica surface with polysaccharides. The SilprBimCl column has larger retention than the other ionic liquid-modified silica columns owing to the large pore size and specific physical and chemical properties of the ionic liquids. 2.93 was the largest retention factor in SilprBimCl column from 5 kDa dextran. Under the SilprBimCl column, the molecular weights of fucoidan, alginic acid and laminarin were 205, 245, and 7–650 kDa respectively. [ABSTRACT FROM AUTHOR]

Microextraction is considered as one of the most critical steps in the entire analytical process because it can effectively remove interference and pre-concentrate the target analytes. Molecularly imprinted polymers (MIPs) are synthetic polymers with a predetermined selectivity for a given analyte, or group of structurally related compounds, which are excellent materials for sample preparation in the process of microextraction owing to their high selectivity and ability. This review provides a critical overview of the synthesis and characterization of MIPs, with a focus on recent applications in the field of solid-phase microextraction (SPME) and liquid-phase microextraction (LPME). The advantages and drawbacks of the applications of MIPs used in SPME and LPME as well as the future expected trends are also discussed. [ABSTRACT FROM AUTHOR]

New magnetic molecularly imprinted polymers with two templates were fabricated for the recognition of polysaccharides (fucoidan and alginic acid) from seaweed by magnetic solid-phase extraction, and the materials were modified by seven types of deep eutectic solvents. It was found that the deep eutectic solvents magnetic molecularly imprinted polymers showed stronger recognition and higher recoveries for fucoidan and alginic acid than magnetic molecularly imprinted polymers, and the deep eutectic solvents-4-magnetic molecularly imprinted polymers had the best effects. The practical recovery of the two polysaccharides (fucoidan and alginic acid) purified with deep eutectic solvents-4-magnetic molecular imprinted polymers in seaweed under the optimal conditions were 89.87, and 92.0%, respectively, and the actual amounts extracted were 20.6 and 18.7 μg/g, respectively. To sum up, the developed method proved to be a novel and promising method for the recognition of complex polysaccharide samples from seaweed. [ABSTRACT FROM AUTHOR]

Fe3O4@hybrid-molecular-imprinted polymers (Fe3O4@HMIPs) with three monosaccharide templates (D-(+)-galactose, L-(−)-fucose, and D-(+)-mannose), and hybrid materials were modified by deep eutectic solvents (DESs). The materials obtained were combined with solid-phase extraction (SPE) to purify of D-(+)-galactose, L-(−)-fucose, and D-(+)-mannose from seaweed, and the SPE procedure was optimized further. Compared to Fe3O4@HMIPs, DESs-Fe3O4@HMIPs were developed to achieve stronger recognition and higher recoveries of D-(+)-galactose, L-(−)-fucose, and D-(+)-mannose from seaweed. The optimal practical recoveries of the three monosaccharides, D-(+)-galactose, L-(−)-fucose, and D-(+)-mannose, purified by DESs-4-Fe3O4@HMIPs from seaweed were 90.12, 92.82, and 91.94%, respectively. When acetone was used as the washing solution, the actual amounts extracted were 6.87, 4.17, and 5.29 mg · g−1, respectively. [ABSTRACT FROM AUTHOR]

A series of ecofriendly ternary deep eutectic solvents (DESs) with different molar ratios were prepared as candidate functional monomers. Three of the optimal ternary DESs as functional monomers were applied to the preparation of molecularly imprinted polymers (MIPs). After synthesis, the proposed polymers were characterized by elemental analysis (EA), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller surface area measurements (BET) and Fourier transform infrared spectroscopy (FT-IR). These MIPs based on ternary DESs with different molar ratios exhibited different absorption capacities of levofloxacin. A sample of levofloxacin (500 ng) was dissolved in a millet extractive (10 mL). All MIPs were used as SPE adsorbents to purify the extracts. According to characterization result, the ternary DES-3 (1:3:1.5) was joined in the synthetic process of MIP-1. The green ternary DES-3-based MIPs had the best selectivity recovery for levofloxacin (91.4%) from the millet extractive. The best selectivity of MIP-1 was attributed to the novel monomer (ternary DES) in the preparation of the materials. Overall, ternary DES-based MIPs have potential applications as media in many research areas. [ABSTRACT FROM AUTHOR]

Ionic liquids with length of alkyl chain and different anions, deep eutectic solvents with choline chloride and 7 different hydrogen bond donors were applied as extraction additives after optimizing the extraction conditions to increase the extraction amounts of rutin, quercetin, and scoparone fromHerba Artemisiae Scopariae. The extraction conditions were optimized as follows: refluxing with methanol with a solid/liquid ratio of 1:120 under 60°C for 60 min after changing the different extraction conditions of: extraction methods (dipping, ultrasonic, reflux and soxlet), extraction solvents (methanol, water and ethanol), extraction temperature (30, 40, 50, 60, 70 and 80°C), extraction time (30, 60, 80, 100 and 120 min), extraction ratio of solid to liquid (1:5, 1:10, 1:20, 1:50, 1:100, 1:120 and 1:150). Under these optimal conditions, the best preformed extraction additive among the 7 kinds of ionic liquids and 7 kinds of deep eutectic solvents extraction additives were selected and optimized with its contraction of 0.5mg/mL. Using the most effective extraction additive, [BMIM][Br], 10275.92 µg/g rutin, 899.73 µg/g quercetin, and 554.32 µg/g scoparone were obtained. Overall, ionic liquids and deep eutectic solvents have potential applications as extraction additives for the extraction of bioactive compounds from nature plants. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents, as an alternative to ionic liquids, have greener credentials than ionic liquids, and have attracted considerable attention in related chemical research. Deep eutectic solvents have attracted increasing attention in chemistry for the extraction and separation of various target compounds from natural products. This review highlights the preparation of deep eutectic solvents, unique properties of deep eutectic solvents, and synthesis of deep-eutectic-solvent-based materials. On the other hand, application in the extraction and separation of deep eutectic solvents is also included in this report. In this paper, the available data and references in this field are reviewed to summarize the applications and developments of deep eutectic solvents. Based on the development of deep eutectic solvents, an exploitation of new deep eutectic solvents and deep eutectic solvents-based materials is expected to diversify into extraction and separation. [ABSTRACT FROM AUTHOR]

Hydrophilic molecularly imprinted chitosan microspheres (HMICS) were synthesized using deep eutectic solvents (DESs)-(3-aminopropyl) triethoxysilane (APTES) as co-functional monomer for the extraction of catechin from green tea with micro-solid phase extraction (micro-SPE). Various factors were studied to optimize the extraction condition during extraction process. The actual extraction amount under the optimal conditions (amount of adsorbent (20 mg), type and volume of washing (acetone, 1.2 mL) and eluting solvent (acetone/acetic acid, 1.0 mL), extraction time (30 min), extraction temperature (40 °C), and sample pH (4)) were obtained at 97.06 mg·g−1. The catechin recovery ranged with ranged with limit of detection (LOD) within 0.09–0.24 µg·mL−1, and limit of quantification (LOQ) within 0.18–0.28 µg·mL−1. From the experimental results in this system, the HMICS was proved to have higher extraction capacity, improving as a promising adsorbent for the extraction of catechin. [ABSTRACT FROM AUTHOR]

Silica-confined ionic liquids were synthesized for solid-phase extraction of polysaccharides, which was determined by high-performance liquid chromatography coupled with RI detection. The sorbent with amino-imidazolium groups was found to be the optimal material by a comparison of the adsorption capacity of fucoidan and laminarin onto different synthetic sorbents. The proper elution solvents for both laminarin and fucoidan were decided from practical tests. The sorbent performed stably and selectively, demonstrating potential applications in the separation of hydrophilic biomacromolecules, such as polysaccharides. [ABSTRACT FROM AUTHOR]

Highlights: [•] A kind of water compatible magnetic imprinted microspheres (WCMM) is synthesized. [•] The WCMM adsorbent of dispersive solid-phase extraction can efficiently extract cyanazine and atrazine from environmental water. [•] The application of dummy template effectively eliminates the problem of template leakage. [ABSTRACT FROM AUTHOR]

Glucose is primarily derived from plant metabolism; it is the primary source of energy for cellular respiration in living organisms. Bioethanol, which is used as fuel, can be obtained from the fermentation of biomass. This article summarizes the current methods of separating glucose and bioethanol. Glucose is generally analyzed by liquid chromatography using a range of sorbents.In the fermentation broth of glucose, the primary produced compound, ethanol, is dissolved in water. Nevertheless, ethanol should be separated to obtain high purity. Distillation is a widely used method and ionic liquids are added to ethanol–water systems to increase separation efficiency. This review discusses the application of new materials (based on silica and membrane) in the separation of ethanol from ethanol–water systems. [ABSTRACT FROM AUTHOR]

This paper reports the application of a multiphase dispersive extraction method to the extraction, separation, and determination of the phenolic acids from Salicornia herbacea L. using silica-confined ionic liquids as sorbents. A suitable sorbent for phenolic acid extraction and separation was first identified based on the adsorption behavior of the phenolic acids on different silica-confined ionic liquids. The sample was then mixed with the optimized sorbent and solvent to achieve multiphase dispersive extraction. The sample/sorbent ratio was optimized using theoretical calculations from the adsorption isotherm and experiments. After transferring the supernatant to an empty cartridge, an SPE process was used to separate the three phenolic acids from the other interference. Through systematic optimization, the optimal conditions produced high recovery rates of protocatechuic acid (91.20%), caffeic acid (94.03%), and ferulic acid (91.33%). Overall, the proposed method is expected to have wide applicability. [ABSTRACT FROM AUTHOR]

The gas chromatographic analysis of fatty acids has attracted considerable interest. In this analysis, the common derivatives of fatty acids, such as fatty acid methyl esters, can be detected using a flame ionization detector and the mass spectra can indicate the true structure of fatty acids. This paper reviews gas chromatographic methods for obtaining fatty acids from marine organisms. The stationary phase and detector for applications in gas chromatography are discussed. This article also reviews the components of fatty acids in marine animals, marine plants and marine microorganisms. [ABSTRACT FROM AUTHOR]

A 17-run Box-Behnken design (BBD) with three factors was used to improve the conditions for extracting astaxanthin from shrimp waste. The astaxanthin level was determined by high performance liquid chromatography (HPLC) using a C18column and a UV detector at 476 nm. The mean extraction yield of astaxanthin at the improved conditions (extraction time 1.4 h, extraction temperature 72.4°C, and liquid-solid ratio 27.3) was 98.7 ± 2.6 µg g−1. A solid-phase extraction (SPE)-HPLC method was developed with a new hybrid organic-inorganic hybrid monolith for further purification of astaxanthin from shrimp waste. The SPE recoveries were ranging from 81.3 ± 2.4% to 86.5 ± 3.3%, and the intra-day and inter-day relative standard deviations (RSDs) of the proposed method were less than 4.3 ± 0.5% and 4.8 ± 0.2%, respectively. BBD increased the extraction efficiency and shortened extraction times significantly. SPE-HPLC with hybrid monolith showed good selectivity and purified astaxanthin from shrimp waste. [ABSTRACT FROM PUBLISHER]

Biogenic amines are present in large quantities in fermented foods and are a key marker for assessing food safety. This paper proposes a novel method for high‐performance liquid chromatography analysis of biogenic amines using deep eutectic solvent as a mobile phase additive. After screening eight synthetic deep eutectic solvents and comparing them with several common additives, deep eutectic solvents based on choline chloride and ethylene glycol showed significant effects in improving the separation of biogenic amines. A Box–Behnken design of 17 runs was used to screen and optimize the key chromatographic parameters, resulting in an expected composition of the mobile phase of 0.73% deep eutectic solvent, 65% acetonitrile, and a column temperature of 28°C. The proposed method exhibited excellent linearity (0.1–50 μg/ml, R2 ≥ 0.9987), limit of detection (0.007–0.031 μg/ml), precision (1.28%–5.34%) and accuracy (87.2%–110.6%). The method can be applied successfully to the separation and analysis of biogenic amines in cooking wine samples. [ABSTRACT FROM AUTHOR]

Abstract: Polyethyleneimine (PEI) and ethylenediamine (EDA) as modifiers were bonded on active carbon (AC) surface for specific selective extraction of quercetin from Oldenlandia diffusa. The characteristics of the modified AC materials that were obtained were investigated by field emission-scanning electron microscopy (FE-SEM) and Fourier transform infrared spectrometer (FT-IR). The interactions between quercetin and the AC materials were investigated by fitting the static adsorption data to four linear and nonlinear adsorption isotherm models. Of these four models, the Langmuir–Freundlich adsorption isotherm was proved the best for investigating quercetin on AC materials. Scatchard analysis was used to evaluate the binding properties of the AC materials for quercetin. Solvent extraction and solid-phase extraction (SPE) were optimized, and the effect of the mobile phase pH was investigated to improve the performance for the separation of quercetin on high performance liquid chromatography (HPLC). The results from the validation of the proposed analytical method demonstrated that the EDA-modified AC was the most suitable SPE cartridge for the purification of quercetin from O. diffusa. [Copyright &y& Elsevier]

Abstract: Water-compatible molecularly imprinted polymers (MIPs) were prepared in water–methanol systems for selective extraction and separation of ciprofloxacin from human urine samples. Molecular recognition properties, binding capability, and chromatographic applications of the MIPs were evaluated and the results revealed the obtained MIPs have high affinity for ciprofloxacin in aqueous environment and the selectivity can be easily controlled by adjusting the pH of mobile phase. After centrifugation, the urine samples were directly injected into the MIPs column and ciprofloxacin could be selectively retained on the column while other biological matrixes were quickly washed out. Good linearity was obtained from 0.1 to 100mgL−1 (r =0.999) with the relative standard deviations less than 3.6%. The limit of detection of the method was 0.03μg/mL and the recoveries were more than 94.5% at three different concentrations. Moreover, by increasing the injection volume, the detection limits of the method could be improved more than 100-folds. [Copyright &y& Elsevier]

Abstract: A sensitive, simple, and accurate method for determination of levofloxacin and its (R)-enantiomer was developed to determine the chiral impurity of levofloxacin in Cravit Tablets material by ligand-exchange high performance liquid chromatography. The effects of different kinds of ligands, concentration of ligands in mobile phase, organic modifier, pH of mobile phase, and temperature on enantioseparation were investigated and evaluated. Chiral separation was performed on a conventional C18 column, where the mobile phase consisted of a methanol–water solution (containing10mmolL−1 l-leucine and 5mmolL−1 copper sulfate) (88:12, v/v) and its flow-rate was set at 1.0mLmin−1. The conventional C18 column offers baseline separation of two enantiomers with a resolution of 2.4 in less than 20min. Thermodynamic data (ΔΔH and ΔΔS) obtained by Van’t Hoff plots revealed the chiral separation is an enthalpy-controlled process. The standard curves showed excellent linearity over the concentration range from 0.5 to 400mgL−1 for levofloxacin and its (R)-enantiomer. The linear correlation equations are: y =1.33×105 x +6297 (r =0.9991) and y =1.34×105 x +3565 (r =0.9997), respectively. The relative standard deviation (RSD) of the method was below 2.3% (n =3). [Copyright &y& Elsevier]

Abstract: Catechin compounds from Korean green tea as potential sources of anticancer and antioxidant components were target materials in this work. The methodologies of solvent extraction and partition were utilized to recover catechin compounds from green tea. The optimum experimental condition was obtained by optimizing operating factors, such as, the extraction solvent, extraction time and operating temperature. After extracting the green tea with water at 80°C for 40min, the extract was partitioned with water/chloroform, which was best suited to remove caffeine impurity from the extract. Further, the resulting extract was partitioned water/ethyl acetate to deeply purify the catechin compounds of EGC, EC, EGCG and ECG. The experimental result in this work could be extended to preparative HPLC to obtain EGCG on commercial scale. [Copyright &y& Elsevier]

An efficient optimization method was suggested to separate biologically active peptides by RP-HPLC. In this work, the binary mobile phase of water and acetonitrile was used with the buffer of trifluoroacetic acid (TFA). The elution profiles were calculated by the plate theory based on the linear and quadratic equations of retention factor, ln k=A+BF, ln k=A+BF+CF2, and F was the vol.% of acetonitrile. We modified the plate theory to calculate elution profile in both isocratic and gradient mode. From the final calculated results, the first mobile phase composition was water in 0.1% TFA/acetonitrile in 0.1% TFA, 81/19 vol.%, then after 7–8 min, the second composition of mobile phase was linearly changed to 79/21 vol.%, and finally after 8 min, it was kept at the isocratic mode. In the experimental conditions, the agreement between the experimental data and the calculated values was relatively good. [Copyright &y& Elsevier]

• The DESs showed unique phase behaviors by adjusting pH. • The DES-HLLME was developed for the extraction of LOF and COF in water samples. • The whole process only took a few minutes with only manually shaken. A fast and efficient kind of homogeneous liquid-liquid microextraction based on the pH-induced transition of deep eutectic solvents (DES-HLLME) was developed for the analysis of two common antibiotics in environmental water, levofloxacin (LOF) and ciprofloxacin (COF). The phase transition behavior of the DESs consisting of thymol and medium-chain fatty acids could be induced by adjusting the solution pH. The consistency and completeness of the DES through phase transition were studied. Then DESs were applied as extractant in HLLME, the important factors, such as types of DES, the volume of DES, the concentration of KOH, the addition of HCl and salt were investigated. Under optimal conditions, the proposed method showed good linear range from 0.5 to 100 μg mL−1 (R2 ≥ 0.9998), satisfied repeatability (LOF: RSD ≤ 4.21%; COF: RSD ≤ 3.57%), high extraction recoveries (LOF: 110.83%; COF: 94.52%). [ABSTRACT FROM AUTHOR]

A hydrophobic deep eutectic solvent (DES) based vortex-assisted liquid-liquid microextraction (LLME) procedure was developed for the effective and rapid determination of thiophanate-methyl (TM) and carbendazim (CA) in lake water and tap water samples, with an excellence extraction efficiency (recovery: 87.2% to 97.4%, enrichment factor: 87.2 to 97.4). Twelve hydrophobic DESs based on terpenoids and fatty acids/alcohols were prepared, and those with the highest recovery for TM and CA were selected. The main parameters, including assisting methods, molar ratio of DES components, volume of DES, and NaCl content that may affect vortex-assisted LLME, were optimized. The intra-day and inter-day relative standard deviation (RSD) of this method were from 1.7% to 3.8% and 1.8% to 4.1%, showing excellent precision. The proposed method exhibited suitable limits of detection (TM: 0.053 µg/mL; CA: 0.007 µg/mL) and limits of quantification (TM: 0.177 µg/mL; CA: 0.024 µg/mL). [ABSTRACT FROM AUTHOR]

Deep eutectic solvent (DES) based extraction methods have promising applications in extracting and separating compounds from plants. In this study, a polarity controlled biphasic extraction system consisting of a hydrophilic DES phase (Hexafluoroisopropanol-choline chloride: HFIP-ChCl) and a hydrophobic DES phase (Menthol-tricaprylylmethylammonium chloride: Menthol-N 8881 Cl) was constructed. The DES based biphasic system was successful in the simultaneous extraction and separation of high polarity compounds, such as chlorogenic acid (CHA), quercetin (QUE) and anthocyanidins (ANT), and a low polarity compound artemisinin(ART), from Artemisia annua Leaves in a single step by the polarity driven recognition targets. By adjusting the mole ratio of the component in each DES phase, the HFIP-ChCl(1:1)/Menthol-N 8881 Cl(2:1) biphasic system showed the best extraction and separation performance. A conductor-like screening model for real solvents (COSMO-RS) was used to monitor and analyze the changes in the surface polarity dynamics of each DES. The results showed that the non-polar intensity increased from 11.89 to 21.06 Å2 with increasing proportion of HFIP in HFIP-ChCl and the non-polar intensity weakened from 16.47 to 10.01 Å2 with increasing proportion of Menthol in Menthol-N 8881 Cl. This model can be efficient for screening suitable DESs in a DES based biphasic extraction system to accommodate compounds with a range of polarities. Supported by the model and experimental data of the DES based biphasic system, 6.21 mg/g ART was transferred to the upper layer (Menthol-N 8881 Cl with 2:1 mol ratio) and 7.89 mg/g CHA, 5.5 mg/g QUE, and 8.9 mg/g ANT were transferred to the lower layer (HFIP-ChCl with 1:1 mol ratio) under the optimal condition (15/1 solvent/solid ratio, 40 °C extraction temperature, 1:1 vol ratio and 30 min extraction time). Therefore, the polarity controlled DES based biphasic extraction system was used to expand the application of DESs in the extraction and separation of bioactive compounds with various polarities. Image 1 • A polarity controlled and recyclable DES based biphasic extraction system was constructed. • DES biphasic system achieved the simultaneous extraction and separation of various polarities compounds. • COSMO-RS was used to monitor and analyze the changes in the surface polarity dynamic of each DES. • The DES biphasic system can be recycled and reused to separate compounds of different polarities. [ABSTRACT FROM AUTHOR]

A type of molecular-imprinted polymer with magnetic molybdenum disulfide as a base and deep eutectic solvent as a functional monomer (Fe3O4@MoS2@DES-MIP) was prepared with surface molecular imprinting method. It was applied as the adsorbent for the selective recognition and separation of (+)-catechin, (−)-epicatechin, (−)-epigallocatechin, (−)-epicatechin gallate, and (−)-epigallocatechin gallate in green tea in the process of magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography (HPLC). The structure of Fe3O4@MoS2@DES-MIP was characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The adsorption properties and selective recognition ability on (−)-epigallocatechin gallate and the other four structural analogues were examined and compared. The results show that the polymer has excellent selective recognition ability for (−)-epigallocatechin gallate, and its adsorption capacity was much higher than that of structural analogues. The Fe3O4@MoS2@DES-MIP not only has the special recognition ability to template a molecule, but also can be separated by magnets with high separation efficiency and can be used in MSPE. [ABSTRACT FROM AUTHOR]

Dispersive liquid-liquid micro-extraction (DLLME) has developed rapidly in recent years because of its simplicity, miniaturization, cost-effectiveness, easy automation, low consumption of sample, and eco-friendliness. In this particular field, a novel class of solvents, known as deep eutectic solvents (DESs), has arisen as a new and very promising tool. DESs have attracted considerable attention as green alternative solvents to conventional solvents because they are not only eco-friendly, non-toxic, and biodegradable organic compounds, but also low cost and easy to produce. This review briefly discusses the unique properties, preparation, and classification of DESs, with particular focus on the utilization of DESs on the DLLME with different types of assisted modifications. Furthermore, this paper discusses the advantages and disadvantages of the application of DESs in DLLME as well as the future trends. • Dispersive liquid-liquid micro-extraction (DLLME) has developed rapidly. • Deep eutectic solvents (DESs) have attracted considerable attention. • The utilization of DESs-DLLME with assisted-modification. • The future expected trends of DESs used in DLLME. [ABSTRACT FROM AUTHOR]

Quercetin is a phytochemical with disease prevention and health promotion activities that has attracted significant research attention. In this study, choline chloride and betaine-based natural deep eutectic solvents were prepared using a heating method. Their physical and chemical properties were also tested. Then, they were applied to extract quercetin from onion and broccoli with ultrasonic-assisted solid liquid method coupled with HPLC. Three factors (temperature, amount, and time) were considered for the optimization of the extraction assays. In the optimal conditions, the extraction recoveries were 88.91–98.99%, 88.45–99.01%, and 89.56–98.74% for quercetin, isorhamnetin, and kaempferol. Tailor-made natural deep eutectic solvents could be applied as sustainable and safe extraction media for biochemical applications. [ABSTRACT FROM AUTHOR]

A novel water-compatible molecularly imprinted resin was prepared in a green solvent deep eutectic solvent (DES). Resorcinol and melamine, as functional monomers with an abundant hydrophilic group, such as –OH, –NH2 and –NH–, were introduced into the molecularly imprinted resin (MIR). Three DESs (choline chloride-ethylene glycol, tetramethylammonium bromide-ethylene glycol and tetramethylammonium chloride-ethylene glycol) were used to synthesize the molecularly imprinted resin and the resulting deep eutectic solvent-based molecularly imprinted resins were characterized by particle size analysis, elemental analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. The resulting deep eutectic solvent-based molecularly imprinted resins were then applied to the adsorption of quinolones (ofloxacin) in water. The adsorption process of deep eutectic solvent-based molecularly imprinted resin followed the static adsorption model, Langmuir isotherm (R2 ≥ 0.9618) and kinetic model pseudo-second-order (R2 > 0.9814). The highest theory adsorption ability of the three kinds of deep eutectic solvent-based molecularly imprinted resins was more than 23.79 mg/g. The choline chloride-ethylene glycol-based MIR was applied to solid-phase extraction for the determination and purification of quinolones (e.g., ciprofloxacin and ofloxacin). The detection limit of deep eutectic solvent-based molecularly imprinted resin-solid-phase extraction method was less than 0.018 mg/L. The recoveries of the deep eutectic solvent-based molecularly imprinted resin-solid-phase extraction method at three spiked levels were 88.7–94.5%, with a relative standard deviation of ≤4.8%. The novel deep eutectic solvent-based molecularly imprinted resin-solid-phase extraction method is a simple, selective and accurate pre-treatment method and can be used to determine the quinolones in environmental water. [ABSTRACT FROM AUTHOR]

Hydrophobic deep eutectic solvents (DESs) were synthesized and developed for the preconcentration of three chlorophenols from wastewater by dispersive liquid–liquid microextraction (DLLME). The analyte concentrations were determined by high-performance liquid chromatography (HPLC). The hydrophobic DESs were prepared with the combination of hydrogen bond donors of decanoic acid or octanoic acid with different hydrogen bond acceptors of quaternary ammonium salts of tetrabutylammonium chloride, tetraoctylammonium chloride, methyltrioctylammonium chloride, and tetraheptylammonium chloride). Following the study of the stability and characterization by Fourier transform infrared spectroscopy, the hydrophobic DESs were developed as extractants and employed for the removal of 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) from wastewater. Using hydrophobic DESs as the microextraction solvents, several key parameters were optimized, including the type and volume of the hydrophobic DES, pH, and time of the extraction procedure. Under the optimized conditions, good recoveries from 90.8% to 93.0% were obtained for the three chlorophenols. The limits of detection were less than 0.05 µg/mL with relative standard deviations between 1.8% and 3.1%. The method was applied for the isolation and determination of synthetic chlorophenols in wastewater. [ABSTRACT FROM AUTHOR]