Dispersive Liquid-phase Microextraction Research Articles

Development of an ecofriendly dispersive liquid phase microextraction method for the preconcentration of β-blockers in waste and environmental samples

Effective sample preparation is crucial in instrumental analysis to enhance selectivity, sensitivity, and instrument protection. The current trend of miniaturization in liquid–liquid extraction aims to conserve solvents and promote environmental sustainability. Liquid phase microextraction, requiring only small volumes of the extractant, facilitates sample preconcentration without the need for evaporation and reconstitution. This study presents the development of an eco-friendly dispersive liquid–liquid microextraction method employing solidification of floating organic droplets for the determination of five β-blocker drugs in waste and environmental samples. The optimization of key variables affecting extraction efficiency, including extractant type and volume, pH of the diluent, dispersion technique, vortexing, and centrifugation time, was carried out. Optimal results were achieved using 50 μL of dodecanol as the extractant, 1 min of vortexing for dispersion, followed by 2 min of centrifugation for phase separation. The sample was then subjected to a 5 min cooling in an ice bath to solidify the dodecanol before UHPLC/UV analysis. The method yielded enrichment factors within the range of 23–55. The applicability of this approach was demonstrated in laboratory waste and environmental water analysis, with acceptable % recoveries ranging from 98.07 % to 101.83 % and %RSD below 1.96. Moreover, we assessed the method’s performance and greenness with ComplexGAPI, BAGI, and carbon footprint. This method not only provides high efficiency and reliability but also aligns with the principles of sustainablility.

Preparation and investigation of green and cheap deep eutectic solvents for determination of essential and toxic metal ions at trace levels in different coffee products

In this research, a vortex-assisted hydrophobic deep eutectic solvent-based dispersive liquid phase microextraction (VA-HDES-DLPME) method was developed to extract some essential (Fe, Mn and Zn) and toxic (Cd and Pb) metal ions from coffee products. After the VA-HDES-DLPME method, the amounts of the metal ions in the HDES-phase were determined by flame atomic absorption spectrophotometry (FAAS). For selective extraction of metal ions, five HDESs (as extraction solvent) were prepared and tested according to the ultrasonic-assisted procedure. Some dispersive solvents were investigated to ensure the dispersion of HDES in the sample solution. In the VA-HDES-DLPME method, heating and centrifugation steps were not required to separate the HDES-phase from the sample solution. Key factors were investigated and optimized to achieve selective and rapid extraction of metal ions. Under optimized conditions, the working range of the VA-HDES-DLPME method for metal ions ranged from 0.03 to 280 μg kg−1. The detection limits of Fe(II), Mn(II), Zn(II), Cd(II), and Pb(II) ions were 0.01, 0.27, 0.02, 0.015, and 0.18 μg kg−1, respectively. Relative standard deviation and extraction recovery for five replicate runs of 5 μg kg−1 of metal ions were in the range of 1.3%–1.9% and 94 ± 4%-98 ± 2%, respectively. Validation of the VA-HDES-DLPME method was tested by studies on three reference materials. In the final step, the VA-HDES-DLPME method was successfully applied to microwave digestion of coffee samples using a standard addition method. The obtained quantitative recoveries showed the good accuracy of the method.

Development of an effervescence‐assisted dispersive liquid phase microextraction using a binary solvent as a simultaneous extraction and preconcentration approach specialized for the analysis of pesticides in grape juice without dilution

AbstractIn this study, a swift and economical extraction and preconcentration method called effervescence‐assisted dispersive liquid‐phase microextraction was developed to analyze the pesticide content of different grape juices. To propel the microextraction method, the sample was transferred to a conical bottom glass test tube, and ammonium chloride was added and vortexed to dissolve. Then, sodium bicarbonate and a mixture of 1,2‐dibromoethane and n‐hexane were added. The tube was located in a water bath and the produced carbon dioxide bubbles dispersed the extraction solvent into the sample. Finally, it was centrifuged and one microliter of the sedimented phase was injected into a gas chromatograph equipped with a flame ionization detector. Under the optimum conditions, the limits of detection and quantification ranged from 0.9 to 4.1 and 3.0 to 13.6 μg/L, respectively. Extraction recoveries and enrichment factors were achieved in the ranges of 36%–80% and 180%–404%, respectively. The inter‐ and intra‐day relative standard deviations were in the ranges of 3.4%–10.6% and 2.6%–9.7%, respectively. Also, the coefficients of determination in the calibration curves were ≥0.990. Short extraction time, no sorbent or costly apparatuses, using inexpensive chemicals, applying microliter levels of the extractant, and no dilution of the real samples are the highlights of the study.

An air-assisted dispersive liquid phase microextraction method based on a hydrophobic magnetic deep eutectic solvent for the extraction and preconcentration of melamine from milk and milk-based products.

In the current research, a fast and sustainable air-assisted hydrophobic magnetic deep eutectic solvent-based dispersive liquid phase microextraction followed by UV-Vis spectrophotometry measurements was optimized for the extraction and determination of melamine in milk and milk-based products. The central composite design was applied for the optimization of factors affecting the recovery of melamine. Quantitative extraction of melamine was achieved using hydrophobic magnetic deep eutectic solvents prepared from a mixture of octanoic acid, aliquat-336, and cobalt(II) chloride. The optimum conditions for extraction were found as follows: 6 extraction cycles, pH 8.2, extraction solvent volume 260µL, and acetone volume 125µL.Interestingly, a centrifugation step was not required to achieve phase separation. Under the optimum conditions, melamine was determined in the linear range of 3-600ngmL-1, the limit of detection (3Sblank/m) of 0.9ngmL-1, and the enrichment factor of 144. The validation of the method was investigated by the analysis of reference materials. Consequently, the method was successfully applied for the analysis of melamine residues in milk and milk-based products.

Optimization of vortex-assisted hydrophobic magnetic deep eutectic solvent-based dispersive liquid phase microextraction for quantification of niclosamide in real samples.

In this manuscript, a green and fast vortex-assisted hydrophobic magnetic deep eutectic solvent-based dispersive liquid phase microextraction (VA-HMDES-DLPME) method was developed for the selective extraction and determination of niclosamide in read samples, including rice, medicine tablets, and water samples. Here, hydrophobic magnetic deep eutectic solvents were used as the extracting solvent without requiring any centrifugation step. In the light of preliminary experiments, important parameters, such as volume of extraction solvent, pH, acetonitrile volume and vortex time, affecting the extraction efficiency of niclosamide were optimized using a Box-Behnken design. The linear dynamic range (0.25-120 µg/L), the limit of detection (0.08 µg/L), the limit of quantitation (0.25 µg/L), preconcentration factor (180), and enrichment factor (130) of the method were determined using optimized data. In particular, the validation parameters of the optimized VA-HMDES-DLPME, including robustness, matrix effect accuracy, and precision, were investigated. In addition to this, intra- and inter-day precisions were determined as≤3.5 % and≤4.1%, respectively. Finally, the optimized method was successfully used for the extraction of niclosamide in the selected samples prior to spectrophotometric analysis.

Dl-carnitine-based green hydrophobic deep eutectic solvent for the enrichment of bisphenol A in mineral water based on ultrasound-assisted liquid-phase microextraction

A powerful pretreatment technique, ultrasound-assisted dispersive liquid-phase microextraction (USA-DLPME) based on dl-Carnitine-based deep eutectic solvent (DES), has been developed to efficiently enrichment of bisphenol A from mineral water samples. The DES-based USA-DLPME technique demonstrated superior extraction efficiency for bisphenol A compared to established organic solvent-based liquid-liquid extraction techniques. The conditions for the extraction of bisphenol A were predicted using the response surface methodology. The effects of pH (A: 2–10), NaCl concentration (B: 0.2–1.0%w/v), DES volume (C: 30–150 μL), and sonication time (D: 1–5 min) were examined using an experimental design. The extraction recovery of Bisphenol A under optimum conditions was achieved at 99.897% (A = 8, B = 0.4%w/v, C = 120 μL, and D = 5 min). Under these conditions, a wide linear range of 1–600 ng mL−1, an enrichment factor of 81.52, a low detection limit of 0.26 ng mL−1 and a limit of quantification of 0.87 ng mL−1 were obtained. Lastly, the proposed technique was used to accurately and reliably identify bisphenol A in various mineral water samples, yielding relative recoveries in the 92–96% range with RSD≤3%. These findings imply that DESs can be widely and successfully used to extract chemicals from actual materials. DESs are a class of innovative green solvents with the potential to replace organic solvents.

Application of instantaneous nebulization dispersive liquid-phase microextraction combined with HPLC for the determination of chalcone and isoflavone in traditional Chinese medicines.

A simple and rapid instantaneous nebulization dispersive liquid-phase microextraction method was developed, and combined with high-performance liquid chromatography for determination of the contents of seven analytes in traditional Chinese medicines. In this study, using the sprinkler device to achieve instantaneous synchronous dispersion and extraction, only one spray can rapidly achieve the concentration and enrichment of seven kinds of chalcone and isoflavones. The key factors affecting the extraction efficiency were optimized including the type and volume of extractant, the pH and salt concentration of the sample phase, and the number of dispersion. Under the optimal conditions, the enrichment factor of the target analytes ranged from 103.1 to 180.9, with good linearity and correlation coefficients above 0.9970. The limits of detection ranged from 0.02 to 0.15ng/mL, with good accuracy (recoveries 91.1 to 108.9%) and precision (relative standard deviations 1.5-7.1%). This method has short extraction time (2 s), low organic solvent consumption and high enrichment effect, so it has a wide application prospects.

Dispersive Liquid Phase Microextraction (DLPME) as a Strategy for CdII Separation and Determination in High-Salinity Produced Waters by Graphite Furnace Atomic Absorption Spectrometry

In this study, we propose a microextraction method for the determination of CdII in produced waters. The process is based on the conversion of CdII ions into a hydrophobic diethyldithiocarbamate (DDTC) complex with its subsequent dispersive liquid phase microextraction (DLPME) from the aqueous medium with chloroform. The organic phase was then diluted with ethanol and Cd absorbance was measured by graphite furnace atomic absorption spectrometry (GF AAS). The experimental conditions related to the DLPME process were investigated, and the best microextraction conditions were achieved at pH = 6.0 (acetate buffer), 7.5 × 10-6 mol L-1 of DDTC, and when using 200 µL of chloroform as the extracting solvent. No dispersing solvent was needed, which allowed the recovery of approximately 140 µL of chloroform extract. Pyrolysis and atomization temperatures of the GF AAS program were determined through the construction of the respective curves. The estimated limits of detection (LOD) and quantification (LOQ) were 5 and 17 ng L-1, respectively, whereas the enrichment factor for the method was 17. Six samples of seawater and five samples of produced waters with salinities between 30 and 270‰ were analyzed as well as two certified reference materials of saline waters.

Development of dispersive inclusion complex microextraction for the analysis of nitrosamines in medicinal products

A new dispersive inclusion complex microextraction (DICM) approach coupled with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the determination of n-nitrosamine impurities in different medicinal products is demonstrated for the first time. The proposed DICM procedures consist of a dispersive liquid phase microextraction steps employing cyclodextrin as an inclusion complex agent to extract n-nitrosamines namely N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosodiisopropylamine (NDIPA), N-ethyl-N-nitrosoisopropylamine (NEIPA) and N-nitroso-di-n-butylamine (NDBA) present in the medicinal products. The sample solutions were prepared by mixing 5% (m/v) NaCl solution with 1.5 mM β-cyclodextrin and 20 mM sodium dodecyl sulphate to form a stable inclusion complex and subsequently extracted into dichloromethane as an extraction solvent. The enriched solution was reconstituted into aqueous solution prior to UPLC-MS/MS analysis. The method showed good linearity in the range of 0.036–1 ng/mL with a correlation coefficient of at least 0.995, acceptable reproducibility (RSD 0.5–5.8%, n=5), low limits of detection (0.011–0.018 ng/mL), and satisfactory relative recoveries (96–105%). The results obtained were found to be at least 10-fold more sensitive comparable to those obtained using validated direct sample dissolutions coupled with UPLC-MS/MS approach.

Determination of Three Pyrethroid Insecticides in Food by Magnetic Ionic Liquid-Based Dispersive Liquid Phase Microextraction (DLLME) with High-Performance Liquid-Chromatography (HPLC)

A simple, green, rapid, and efficient magnet ionic liquid (MIL) dispersive liquid–liquid microextraction (DLLME) method coupled with high-performance liquid chromatography (HPLC) was successfully developed for the determination of three trace pyrethroids (fenvalerate, beta-cypermethrin, and bifenthrin) in water and food samples. Tri-hexyl-tetradecyl-phosphonium tetra-chlorocobalt (II) [P6,6,6,14 +]2[CoCl4 2−] was explored as the extraction solvent due to its magnetic susceptibility, low ultraviolet absorbance, difficulty to hydrolyze in aqueous solution, and high extraction capacity. Important factors of extraction efficiency, such as the mass of MIL, pH, and ionic strength, were optimized. The spiked recoveries of the targets in water and food samples were from 96.3 to 103.8%. The detection limits were from 0.75 to 1.75 ng ml−1. The results indicated that the developed MIL-DLLME method based on [P6,6,6,14 +]2[CoCl4 2−] as the extraction solution has the advantages of rapid and high efficiency and was employed to determine pyrethroids in water and food samples.

Deep eutectic solvent (DES) based dispersive Liquid-Phase microextraction of Sunset yellow FCF in food and pharmaceutical products

In this study, a new, sensitive, rapid, simple, cheap, readily available, and rather safe dispersive liquid–liquid microextraction method (DLLME) utilizing a deep eutectic solvent (DES) as the green extraction solvent was developed for the extraction and determination of sunset yellow forColoringFood (FCF), in drugs, vitamins, beverage, foods, and environmental samples. The method is based on the deep eutectic solvent system containing a kind of cationic and anionic (hydrogen bond donor/ hydrogen bond acceptor) species. For this purpose, decanoic acid and tetrabutylammonium bromide (molar ratio of 2:1) were used to obtain a deep eutectic solvent. Sunset yellow FCF is analyzed with a UV–Vis spectrophotometer after ultrasonication-assisted dispersive liquid-phase microextraction procedure. The essential operational parameters such as pH, DES volume, THF volume and sample volume were found 2.0, 200, 400 μL and 20 mL, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were found at pH 2.0 as 0.05 μg L−1 and 0.17 μg L−1, respectively. The enrichment technique was validated by using addition/recovery studies and applied to the determination of analyte content of various drugs, vitamins, beverages, foods, and environmental samples.

COSMO-RS evaluation as a tool for prediction of solvents in dispersive liquid-phase microextraction: Evaluation of conventional solvents and ionic liquids as extractants

This work assesses the prediction capability of COSMO-RS for solvent selection in dispersive liquid phase microextraction systems. The assessment is performed by comparing experimental partition ratios from previous works and calculated ones for different systems, including pesticides, herbicides, polyaromatic aromatic hydrocarbons, and halogen-containing pollutants from water samples. Results indicate that COSMO-RS mainly overestimates the partition ratios. Despite this, a priori analysis was carried out for conventional solvents used as extractants. Results showed that for pesticides and herbicides, COSMO-RS predictions agree just for a few extractants. For polyaromatic hydrocarbons (PAHs), the ring structure is a crucial parameter in extractants’ selection, and for Halogenated pollutants, the halogen content and kind of substitution are crucial to correct trend prediction. Besides this, ILs also were studied, finding that COSMO-RS overestimates the use of ILs, and higher deviations are found for longer alkyl chain cations. However, the Dichlorodiphenyltrichloroethane (DDT) metabolite extraction with ILs is well predicted. Dispersants were also evaluated, but depending on the kind of pollutant, different deviations were found.

Analysis of tamoxifen and its main metabolites in plasma samples of breast cancer survivor female athletes: Multivariate and chemometric optimization.

A sensitive method based on liquid chromatography combined with a diode array detector was developed and validated to simultaneously determine tamoxifen, and its active metabolites N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen in human plasma samples. The green and sustainable vortex-assisted dispersive liquid-phase microextraction technique based on the natural hydrophobic deep eutectic solvent was used for the extraction and preconcentration of the analytes. Chemometrics and multivariate analysis were used to optimize the independent variables including the type and volume of deep eutectic solvent, extraction time, and ionic strength. Under optimal conditions, calibration curves were linear in a suitable range with the lower limits of quantification (0.8-10.0μg/L), which covered the relevant concentrations of the analytes in plasma samples for a clinical study. Intra- and interday precision evaluated at three concentrations for the analytes were lower than 8.2 and 12.1%, respectively. Accuracy was in the range of 94.9-104.7%. The applicability of the developed method on human plasma samples illustrated the range 45.1-72.8, 98.4-128.3, 0.9-1.2, and 2.7-6.1μg/L for tamoxifen, N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen, respectively. The validated method can be effective for the pharmacokinetics, pharmacodynamics, and therapeutic drug monitoring studies of tamoxifen and its main metabolites in biological fluids.

Development of an in–syringe gas–assisted density tunable solidification of floating organic droplet–based dispersive liquid phase microextraction method coupled with HPLC–MS/MS for monitoring amikacin in biological fluids

A new sample preparation method named in–syringe gas–assisted density tunable dispersive liquid phase microextraction based on solidification of floating organic droplet has been introduced. This method was coupled with high–performance liquid chromatography–tandem mass spectrometry and used for the extraction and quantification of amikacin in plasma and exhaled breath condensate (EBC) samples of the patients receiving amikacin. In the proposed approach, an inert gas is bubbled into a syringe barrel containing aqueous solution of the analyte and a mixture of low density extraction solvent and volatile density modifier. Consequently, the density modifier is evaporated and the analyte is migrated into the released extractant droplets. Basic parameters affecting efficiency of the developed method were optimized. Under optimum conditions, the method limits of detection were 0.06 and 0.29 ng/mL in EBC and plasma, respectively. The extraction recoveries were 90% and 87% in EBC and plasma, respectively. Also, the obtained relative standard deviations were below 9.5% and 9.8% for EBC and plasma, respectively. Considering these results, the developed method provides a quick and efficient way to determine amikacin in patients’ biological fluids and can be used widely in drug monitoring and clinical studies.

Sustainable valorization of papaya peels for thrombolytic cysteine protease isolation by ultrasound assisted disruptive liquid phase microextraction with task specific switchable natural deep eutectic solvents

The present investigation deals with task-specific purification of thrombolytic cysteine protease from Carica papaya peels using switchable eutectic solvent-based ultrasound-assisted dispersive liquid-phase microextraction. Four switchable polarity natural deep eutectic solvents were synthesized and their thermo-physical profile was recorded as a function of temperature. Ultrasound-assisted liquid phase microextraction was performed yielding 33.2 mg/g of papaya protease. Kinetic and thermodynamic modeling of the extraction process signifies that first-order rate laws describe the extraction process with an optimal time of 15 min. Ultrapure fractions were obtained from copper immobilized metal affinity chromatography resulting in a purity fold of 48.6 and specific enzyme activity of 112.5. The thrombolytic activity of the resulting ultrapure protease fraction was determined by the blood clot digestion assay yielding 4126 U/mg of thrombolytic papain.

In-situ decomposed nanofluids dispersive liquid-phase microextraction for detection of seven triazole fungicidets in fruit juices and tea drinks

A novel, eco-friendly and efficient in-situ decomposed nanofluid dispersive liquid-phase microextraction approach was developed to detect myclobutanil, flusilazole, hexaconazole, penconazole, epoxiconazole, paclobutrazol and diniconazole in tea drinks and fruit juices by high-performance liquid chromatography. Various new nanofluids were prepared physically using multi-walled carbon nanotubes and hydrophilic deep eutectic solvents, with acetic acid/ DL-lactic acid/glycerol/propylene glycol/ethylene glycol/urea and choline chloride used as the hydrogen-bond donor and acceptor respectively. The nanofluids in the sample solutions were decomposed in-situ, while multi-walled carbon nanotubes and deep eutectic solvents served as the adsorbent and carrier/stabilizer/dispersing agent, respectively. One-factor-at-a-time tests showed the optimized parameters for extracting triazole fungicides were 10 mL and pH 6 of sample solutions, 300 μL of nanofluids ([choline chloride: ethylene glycol]: multi-walled carbon nanotubes = [1:2] : 20), 8% sodium chloride, 9 min of vortex, 5 min of centrifugation, 1000 μL of eluent methanol, and 2 min of elution. The new approach performed well with linear range, relative recovery, detection limit, quantification limit, and inter- and intra-day relative standard deviations of 10-10000 μg/L, 70.03-107.14%, 3.34-8.30 μg/L, 10-25 μg/L, < 11.30% and <13.01%, respectively. The adsorption isotherms of triazole fungicides were well fitted by a Freundlich model and a pseudo-second-order kinetic model, revealing that the adsorption process accorded with the theories of multilayer adsorption and chemical adsorption. This environmental approach can triumphantly detect residual triazole fungicides in real tea drinks and fruit juices, and is a potentially promising technique for detecting food matrices.

Vortex-assisted dispersive liquid-phase microextraction for the analysis of main active compounds from Zi-Cao-Cheng-Qi decoction based on a hydrophobic deep eutectic solvent.

In this study, a vortex-assisted hydrophobic deep eutectic solvent dispersive liquid-phase microextraction was developed and used for the extraction and preconcentration of six main active compounds in Zi-Cao-Cheng-Qi decoction. The deep eutectic solvent, prepared by mixing tetrabutylammonium chloride and hexanoic acid at a molar ratio of 1:1, was added to the sample solution containing the analytes. In the absence of disperser, the extractant was rapidly dispersed into fine droplets by the aid of vortex and adequately contacted with the analytes. Some key parameters affecting the approach including extraction solvent type and volume, sample phase pH, extraction time, centrifugation time, and salt concentration were investigated and optimized. Under the optimum conditions, enrichment factors of the target analytes were in the range of 3-330. The calibration graphs were linear with a correlation coefficient (r) ≥ 0.9929. The detection limits were 0.3-0.9ng/mL, and the satisfactory precisions (relative standard deviations, 0.5-8.9%) and accuracies (relative recoveries, 91.1-102.2%) were also obtained. The developed method was rapid (only 2min), eco-friendly, effective, and easy to operate. And it has been successfully applied to simultaneous extraction, enrichment, and determination of the main active compounds in a traditional Chinese medicinal formula coupled with high-performance liquid chromatography.

A fast and sensitive detection of low-level chloramphenicol in food samples using the IMS/homogenizer assisted DLPME combination

A new dispersive liquid-phase microextraction (DLPME) assisted by a homogenizer was employed for the extraction-preconcentration of chloramphenicol. The combination of this method with the ion mobility spectrometry (IMS) provided a fast and sensitive way to chloramphenicol analysis in food samples. The effect of parameters influencing the extraction efficiency was evaluated. The type and amount of solvent used, the pH and ionic strength of the sample solution, and the rate and time of homogenization were the investigated parameters. The obtained calibration curve under the optimized conditions was linear in the range from 0.5 to 20 μg L−1. The detection limit and limit of quantitation were calculated 0.13 and 0.43 μg L−1. The appraised intra-day and inter-day relative standard deviations of the method were evaluated to be 4.8 % and 6.2 %, respectively. The proposed method allowed to access an enrichment factor of 821. The applicability of this method was examined for the determination of chloramphenicol in a cow milk, and two chicken meat samples purchased from local providers (Zanjan Province, Iran). The relative recoveries were found in the range of 91.4–112.0 %.

Strategies to improve the challenges of classic dispersive liquid-liquid microextraction for determination of the parabens in personal care products-One step closer to green analytical chemistry

Gas flow-assisted dispersive liquid-phase microextraction based on deep eutectic solvent was used to determine parabens in personal care products such as mouthwash, lidocaine gel, aloe vera gel, and skin tonic. A homemade extraction device was innovated, in which by passing the stream of gas bubbles through the deep eutectic solvent a thin layer of the extraction phase is coated on the surface of the bubbles. The extraction is finally achieved when the bubbles are going up through the sample. The single-factor experiments and response surface methodology were applied to optimize the independent variables. The linear range of the method was 0.5 to 1000 µg L−1, the coefficient of determination for the goal analytes was higher than 0.9989, the instrumental limit of detections were in the range 0.2–0.3 μg L−1, and the instrumental limit of quantifications were in the range 0.5–1.1 μg L−1, the relative standard deviations were <5.2% for repeatability and <11.2% for intermediate precision, and the enrichment factors were 66 to 87 obtained under the optimized conditions. A spiking approach by means of standard material was used to estimate accuracy. The relative recoveries were in the range 95.8–105.2%. By using mentioned strategies, the organic waste and energy consumption reduced, toxic reagents replaced with safer ones, and operator safety enhanced. Accordingly, these benefits have been simultaneously attained and, the proposed method was one step closer to automation and sustainable analytical chemistry.

Ultrasound-assisted dispersive liquid-phase microextraction by solidifying L-menthol-decanoic acid hydrophobic deep eutectic solvents for detection of five fungicides in fruit juices and tea drinks.

An ecofriendly and efficient ultrasound-assisted deep eutectic solvents dispersive liquid-phase microextraction by solidifying the deep eutectic solvents-rich phase was developed to determine azoxystrobin, fludioxonil, epoxiconazole, cyprodinil, and prochloraz in fruit juices and tea drinks by high-performance liquid chromatography. A varieties of environmental hydrophobic deep eutectic solvents serving as extraction agents were prepared using L-menthol and decanoic acid as hydrogen-bond acceptor and hydrogen-bond donor, respectively. The deep eutectic solvents were ultrasonically dispersed in sample solutions, solidified in a freezer and easily harvested. The main variables were optimized by one-factor-at-a-time and response surface test. The new method performs well with relative recovery of 71.75-109.40%, linear range of 2.5-5000 μg/L (r ≥ 0.9968), detection limit of 0.75-8.45 μg/L, quantification limit of 2.5-25 μg/L,, and inter- and intraday relative standard deviations below 13.53 and 14.84%, respectively. As for the extraction mechanism, deep eutectic solvents were disposed into many fine particles in the solution and captured the analytes based on the changes of particle size and quantity in deep eutectic solvents droplets after extraction. The environmental method can successfully detect fungicide residues in real fruit juices and tea drinks.