Ultrasound-assisted Liquid-phase Microextraction Research Articles

Alcohol-based hydrophobic deep eutectic solvents and ultrasound-assisted liquid phase microextraction followed by GC-MS for the extraction and analysis of organophosphorus pesticides in the blood of farmers.

Organophosphorus pesticides (OPPs) are a group of pesticides that are most widely used in the agricultural sector, and farmers are exposed to these chemicals more than other members of society. In this work, an environmentally friendly, simple, and safe ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) method using alcohol-based hydrophobic deep eutectic solvents (HDESs) followed by gas chromatography-mass spectroscopy (GC-MS) was developed for the extraction and determination of OPPs in the blood of farmers studied in Ravansar cohort. DESs synthesized from thymol as hydrogen bond donor (HBD) and aliphatic alcohols as hydrogen bond acceptor (HBA) have been used as extractants. Under optimal experimental conditions, the reproducibility of the method based on 7 replicate measurements of 10 µg L-1 of OPPs in blood samples was in the range of 1.4-3.8%. The method showed a linearity in the range of 0.01-150 µg L-1. The limits of detection and limits of quantification were between 0.003 and 0.02 µg L-1 and 0.01-0.05 µg L-1, respectively. The matrix effect and accuracy of the method were confirmed by spiking different amounts of OPPs in real blood samples and obtaining relative recoveries in the range of 91-112%. The results showed that the concentration of OPPs in the case group was significantly higher than in the control group, which is because the case group was exposed to OPPs during the spraying of agricultural products.

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.

An eco-friendly ultrasound-assisted deep eutectic solvent-based liquid–phase microextraction method for enrichment and quantification of nickel in environmental samples

An eco-friendly and easy ultrasound-assisted liquid phase microextraction approach using deep eutectic solvent (UA-DES-LPME) was established to preconcentrate and separate trace amount of nickel (Ni(II)) in various environmental samples before flame atomic absorption spectrometric estimation. In this method, Ni(II) was complexed with 2-(benzothiazolyl azo) orcinol reagent. The impacts various parameters on the microextarction of Ni(II) was investigated. The calibration graph is linear in the range of 1–500 µg L−1 and limits of detection and quantification were determined as 0.27 and 0.90 μg L−1, respectively. The RSD% and preconcentration factor were 2.30% and 100, respectively. The analysis of certified reference materials demonstrated the validity of the established procedure. The microextraction method provided here simple, rapid, cheap, green and was effectively used to determine nickel levels in a variety of environmental samples with recoveries ranged of 95.0–98.54%.

Sustainable eutectic mixture-based ultrasound assisted multifaceted valorisation of pineapple waste for bromelain and bioethanol production

A large number of pineapple residues like peels, leaves and stems generated during processing remains underutilized. The current investigation provides one-pot task-specific valorisation of these residues by sequential extraction of bromelain and saccharification of cellulose residue for bioethanol production. Employing natural deep eutectic solvents (NADES) prepared by mixing ammonium salts with imidazole and glycerol has guaranteed sustainable extraction of bromelain. Ultrasound-assisted liquid phase microextraction (UA-LPME) was performed and NADES with moderate density (TBC:I:G/sodium sulphate) was observed to have a higher bromelain yield and purity. Response Surface Methodology-based optimization of UA-LPME was carried out and solid: liquid ratio (25 ml/g), ultrasound time (17.5 min) and ultrasound temperature (45 °C) were observed to be influential variables resulting in an optimal bromelain yield of (87%). Sequential fractionation of the enzyme concentrate with gel filtration chromatography and anion exchange chromatography has resulted in a corresponding purity fold of 89.27. The cellulose-rich residue remaining after bromelain extraction was enzymatically saccharified (Cellic CTec2) for bioethanol production (12.7 g/L). This novel approach guarantees sustainable valorisation of pineapple waste using NADES as a sustainable extraction medium.

Deep eutectic solvent in ultrasound-assisted liquid-phase microextraction for determination of vanadium in food and environmental waters

A method based on ultrasound-assisted liquid-phase microextraction (UA-LPME) was developed for the determination of vanadium in food and environmental water samples. Preconcentration is based on the extraction of V(V) ions in a deep eutectic solvent (DES), composed of choline chloride and phenol at a molar ratio of 1:2. Vanadium is extracted in the form of a complex consisting of V(V) and 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP). The extraction solvent is dispersed in the aqueous solution using ultrasound. Tetrahydrofuran (THF) is used to aid dispersion. Detection was performed directly in the solvent after centrifugation and removal of the rich phase by digital image colorimetry (DIC). Under optimized conditions, the method presented a limit of detection of 0.3 μg L−1 and an enrichment factor of 50. The procedure was successfully applied to determine V(V) and V(IV) species in environmental water. Total vanadium was also determined in food samples. The proposed method follows the principles of green chemistry, as it uses an alternative solvent and generates few residues.

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.

Determination of benzotriazole and benzothiazole derivatives in tea beverages by deep eutectic solvent-based ultrasound-assisted liquid-phase microextraction and ultrahigh-performance liquid chromatography-high resolution mass spectrometry

Benzotriazole (BTRs) and benzothiazole (BTHs) derivatives are a group of high production volume chemicals with emerging health concern, which found in tea beverages raising potential risks for food safety and human health. The present work describes a simple method using a “green” deep eutectic solvent (DES) based-ultrasound-assisted liquid-phase microextraction (UALPME) to rapidly extract BTRs and BTHs from tea beverages, and then applying UHPLC-electrospray ionization (+)-quadrupole time-of-flight mass spectrometry for detection and quantification. To overcome the challenges related to different experimental conditions, a Factorial Multilevel Categoric Design and a Face Centered Central Composite Design were applied to screen and optimize the parameters for the DES-UALPME procedure, respectively. After optimization, the method was validated and shown to possess low limits of quantification (LOQs; 1.5–12 ng mL−1), high precision (3–13%), and satisfactory accuracy (65–107%). The developed method was then successfully applied for the analysis of some selected BTRs and BTHs in tea beverages.

Micro-spectrophotometric determination of nickel in Gentiana rigescens after switchable hydrophilicity solvent-based ultrasound-assisted liquid phase microextraction

In this work, switchable hydrophilicity solvent-based ultrasound-assisted liquid phase microextraction (SHS-UA-LPME) was combined with micro-volume UV-vis spectrophotometry for the determination of trace nickel in the medicinal plant Gentiana rigescens Franch. ex Hemsl. (G. rigescens) samples for the first time. Micro-volume spectrophotometry has the characteristics of microanalysis, economy and low operation cost, which is feasible to be combined with miniaturized enrichment method. Dipropylamine (DPA) as a switchable solvent completed the extraction during the phase conversion process. It was changed from hydrophobic to hydrophilic under the action of HCl, and then completed phase transition under the action of NaOH. The parameters influencing the extraction efficiency were investigated. Under the optimal conditions, the enhancement factor (EF), the limit of detection (LOD), the limit of quantitation (LOQ) and relative standard deviation (RSD, n = 7) were 28, 0.02 µg/L, 0.067 µg/L and 1.4%, respectively. The established method was applied to the determination of G. rigescens samples collected from the local field with satisfactory results.

Deep eutectic solvent-based ligandless ultrasound-assisted liquid-phase microextraction for extraction of cobalt ions from food samples prior to spectrophotometric determination

An innovative environmentally friendly deep eutectic solvent-based ligandless ultrasound-assisted liquid-phase microextraction was introduced for spectrophotometric determination of trace amount of cobalt. n-phenyliminodiacetic acid: choline chloride (2:1 mol ratio) as a novel DES was prepared for extraction of cobalt ions which is both as chelating agent and extraction solvent. The pivotal factors affecting the proposed method including pH, time, temperature, extraction solvent volume, ionic strength, and sample volume were investigated. At optimum conditions, limit of detection and limit of quantification of 5.23 µg L−1 and 17.67 µg L−1 were achieved respectively. The linear range of 20–200 µg L−1 and precision (relative standard deviation %) of 3.4 for 100 µg L−1 Co+2 solution were gained. The proposed method was successfully applied in water samples, tomato sauce, black and green tea, and dark chocolate with high recovery values (%) of 94–105.

Task-specific deep eutectic solvent based extraction coupled cascade chromatography quantification of α-glucosidase inhibitory peptide from Ocimum tenuriflorum seeds

A sustainable method for purification and quantification of α-glucosidase inhibitory peptides from Ocimum tenuriflorum is described in the present investigation. Nine tailor-made DESs under diverse categories were synthesized and their thermophysical properties were determined. Selective extraction of these therapeutic peptides using sustainable DESs is carried out. Three DESs having better phase ratios were selected and their partition coefficient was assessed with a tripeptide as a marker. Ultrasound-assisted liquid-phase microextraction (UA-LPME) based purification of bioactive peptides is performed. Further, response surface methodology based optimization for effective isolation of α-amylase inhibitory peptide from mango seed hydrolysate for DES formed with carnitine and maltose was determined as 96%. Preparative purification (43 µg/g) of bioactive peptides was carried out with size exclusion chromatography. The preconcentrated fractions were exposed to anion exchange chromatography and ultrapure peptides (88%) with high inhibitory activity were obtained. α-amylase inhibition kinetics was established for the resultant ultrapure bioactive peptides to evaluate and quantify its inhibitory property.

Deep eutectic-based vortex-assisted/ultrasound-assisted liquid-phase microextractions of chromium species

In the present work, vortex-assisted liquid-phase microextraction (VA-LPME) and ultrasound-assisted liquid-phase microextraction (UA-LPME) techniques were used for the speciation of chromium (Cr3+/Cr6+) followed by their determination using flame atomic absorption spectrometry. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as a chelating agent to form a hydrophobic complex with Cr3+; then, it was extracted by choline chloride–phenol mixture, as an extraction solvent. A solution of 1.0 mol L−1 ascorbic acid was used as a reducing agent to convert Cr6+ to Cr3+ (total chromium), and the concentration of Cr6+ was determined from the subtraction of Cr3+ form total chromium. The efficiency of two microextraction techniques was compared in terms of type and amount of extraction solvent, type and volume of extraction solvent, pH of solution, volume of tetrahydrofuran (THF), and extraction time. Based on the obtained results, the extraction recoveries of VA-LPME and UA-LPME techniques are 52% and 60%, respectively. Therefore, UA-LPME is superior technique than VA-LPME. By optimizing different parameters affecting the recovery percentage (RP) of Cr3+, the calibration curve was depicted in the concentration range of 1.5–375.0 ng mL−1 Cr3+ with a correlation coefficient of 0.9937. The limit of detection was 0.4 ng mL−1, and the relative standard deviation (RSD%) for seven replicate analyses of 50.0 µg L−1 of Cr3+ was 3.6%. Finally, the UA-LPME method was successfully applied for the determination of Cr species in different food and water samples.

High selective purification of IgY from quail egg: Process design and quantification of deep eutectic solvent based ultrasound assisted liquid phase microextraction coupled with preparative chromatography

The present research investigates on task-specific deep eutectic solvents (TDES) based aqueous two-phase extraction and purification of immunoglobulins by chromatography from quail egg. The synthesis of TDES was accomplished with quaternary ammonium salt as hydrogen bond acceptor (HBA) and glycerol as hydrogen bond donor (HBD). Aqueous two-phase (ATPS) formation of TDESs with various salts was established and phase partitioning ability was evaluated using standard bovine immunoglobulin. Ultrasound-assisted liquid-liquid microextraction (UA-LLME) was performed with ATPS of better partitioning ability for quail egg yolk. Optimization of influential variables with response surface methodology was accomplished and maximum yield was achieved for 85% (v/v) of NADES for feed of 18 μg/ml of egg yolk isolate with ultrasound temperature of 35 °C and 12 min contact time respectively. The quantification of recovery was accomplished by gel filtration process with the determination of retention time, volume and resolution of separation using marker protein. Ultrapure immunoglobulin-Y (IgY) is achieved with anion exchange chromatography and yield was calculated. The results revealed that the selective concentration of immunoglobulin-Y from quail egg yolk could be performed using environment-friendly TDES based UA-LLME coupled with chromatography.

A sensitive and selective deep eutectic solvent-based ultrasound-assisted liquid phase microextraction procedure for separation-preconcentration and determination of copper in olive oil and water samples

ABSTRACTA green and simple deep eutectic solvent-based ultrasound-assisted liquid phase microextraction method has been developed for the preconcentration of copper as 2-(5-bromo-2-pyridylazo)-5-(diethylamino) phenol chelates. The effects of pH, ligand concentration, DES volume, sample volume, and tetrahydrofuran volume were investigated. Analytical performance parameters like limit of detection, limit of quantification, preconcentration factor, and relative standard deviation were determined as 6.6 μg L−1, 21.8 μg L−1, 15, and <5%, respectively. Validation of the developed method was checked by the analysis of certificated reference materials. The procedure was successfully applied to determination of copper in olive oil and water samples.

Usage of deep eutectic solvents for the digestion and ultrasound-assisted liquid phase microextraction of copper in liver samples

In this study, we used deep eutectic solvents for digestion and ultrasound-assisted emulsification liquid phase microextraction (UA-ELPME) of copper in liver samples. Different types of DESs were prepared for digestion and microextraction steps. DESs consisting of lactic acid and choline chloride for the digestion step and DESs consisting of tetrabuthylamonium chloride and decanoic acid for ultrasound-assisted emulsification liquid phase microextraction were used in this method. The liver samples were digested by using DES-based digestion method. After digestion step, Cu(II) ions in aqueous phase were complexed with sodium dimethyl dithiocarbamate (NaDMDTC) and the obtained hydrophobic complex was extracted to tetrabuthylamonium chloride-decanoic acid DES phase. A microsample injection system coupled with flame atomic absorption spectrometer (MS-FAAS) was used in the detection of copper. LOD, LOQ, PF and % RSD were determined as 4.00, 13.2 µg L− 1, 10 and 3.2%, respectively. The proposed microextraction procedure was successfully applied to copper contents of the liver samples.

Deep eutectic solvent based advance microextraction method for determination of aluminum in water and food samples: Multivariate study

Preconcentration of aluminum Al3+ was carried out by a novel deep eutectic solvent based ultrasound-assisted liquid phase microextraction (DES-UALPME) method. The deep eutectic solvents (DESs), a green solvent was first time used for enrichment and quantification of very low concentration of Al3+ in water and food samples, prior to analysed by electrothermal atomic absorption spectrometry (ETAAS). In present method it was observed that % recovery of Al-8-hydroxyquinoline chelates efficiently extracted by DES solvent. Pre-enrichment factor and limit of detection were observed to be 50, and 0.032μgL−1, respectively. Developed procedure was validated with the CRM (SLRS-5 river water) of Al and a good agreement was observed in results of measured value to the certified value. The RSD was calculated as 3.3%. The presented procedure was successfully carried out to different water and food samples.

Ultrasonic assisted dispersive liquid-liquid microextraction method based on deep eutectic solvent for speciation, preconcentration and determination of selenium species (IV) and (VI) in water and food samples

A novel ultrasound-assisted liquid phase microextraction (UALPME) based on environmental friendly extractants, deep eutectic solvent (DES) was first time presented for speciation of selenium. In present study, five DES solvents of different composition was prepared and used as efficient extractive medium for hydrophobic chelate of Se(IV) with 3,3′-Diaminobenzidine (DAB). The total inorganic Se species were determined after pre-reduction of Se(VI) to Se(IV), prior to applying developed method. The concentration of Se(VI) was calculated by the difference of Se(IV) values and total selenium contents. The concentration of Se in DES rich phase was measured with electrothermal atomic absorption spectrometer (ETAAS). The effects of different parameters on extraction efficiency of study analyte, including pH, ligand concentration, type and volume of DES, sonication time, volumes tetrahydrofuran and aqueous samples were examined. At the optimum conditions, limit of detection and quantification, preconcentration factor, and relative standard deviation (RSD %) were determined as 4.61ngL−1, 15.4ngL−1, 50% and 4.1%, respectively. The accuracy of the presented method was confirmed by analysis of certified reference material and standard addition method for different water and ice tea samples. The developed method was effectively applied to real water and food samples.

Ultrasound assisted deep eutectic solvent based on dispersive liquid liquid microextraction of arsenic speciation in water and environmental samples by electrothermal atomic absorption spectrometry

A green and highly efficient deep eutectic solvent ultrasound-assisted liquid phase microextraction (DES-UALPME) method have been developed for speciation of As(III) and As(V). Extraction of As(III) was observed by using sodium diethyldithiocarbamate (DDTC) as a chelating agent, choline chloride-phenol as extracting solvent and tetrahydrofuran (THF) as dispersive solvent. Arsenic concentration was determined by electrothermal atomic absorption spectrometry (ETAAS). The developed procedure established on significant recoveries of As(III) and also As(V) recoveries were obtained as <5%. Whereas the reduction of As(V) was achieved with potassium iodide and ascorbic acid. This technique was useful for the analysis of total arsenic. Whereas As(V) was originated as variation among total As and As(III) levels. The key factors affecting the microextraction efficiency including pH, ultrasonication time, and amount of ligand were studied and optimized. Under optimum conditions, limit of detection (LOD), limit of quantification (LOQ), preconcentration factor (PF) and relative standard deviation (RSD) were calculated as 10ng L−1, 33ng L−1, 25 and 4.3%, respectively. The accuracy of developed technique was carried through the analysis of certified reference materials. Technique was used for the speciation of As(III) and As(V) in water samples collected from Tokat, Turkey. It was also applied for the determination of total arsenic within food and environmental samples.

Deep eutectic solvent based ultrasonic assisted liquid phase microextraction for the FAAS determination of cobalt

A novel deep eutectic solvent based ultrasound-assisted liquid phase microextraction (DES-UALPME) has introduced for preconcentration of cobalt. Deep eutectic solvents (DESs) are studied as a green and eco-friendly solvents. In this method, 1-nitroso-2-naphthol was used as ligand. Cobalt concentration in DES rich phase was measured by a microsample injection system coupled with flame atomic absorption spectrometer (MS-FAAS). Under optimum conditions, LOD, LOQ, preconcentration factor (PF) and % RSD were determined as 1.10μgL−1, 3.60μgL−1, 15 and 7.1% respectively. The accuracy of the developed method was evaluated by the analysis of a pharmaceutical supplement and tea samples. Recoveries of certified reference materials and spiked samples were obtained in the range of 97–105%. Finally, the performance characteristics of the proposed method were compared with other liquid phase microextraction procedures.

Comparison of ultrasound-assisted cloud point extraction and ultrasound-assisted dispersive liquid liquid microextraction for copper coupled with spectrophotometric determination

In this work, ultrasound-assisted cloud point extraction (UA-CPE) and ultrasound-assisted dispersive liquid liquid microextraction (UA-DLLME) were investigated and compared firstly as ultrasound-assisted liquid phase microextraction methods, which were coupled with spectrophotometer for copper preconcentration and detection. Compared to conventional CPE and DLLME, the extraction patterns were changed and improved by the effect of ultrasound. As novel methods, their applications were expanded and the analytical performance of spectrophotometric determination for copper was considerably improved. The influence factors of UA-CPE and UA-DLLME were studied in detail. Under the optimal conditions, the limits of detection (LODs) for copper were 0.7μgL−1 of UA-CPE and 0.8μgL−1 of UA-DLLME with sensitivity enhancement factors (EFs) of 17 and 16. The developed methods were applied to the determination of trace copper in real water samples with satisfactory analytical results.

High-Throughput Determination of Octanol-Water Partition Coefficients by Ultrasound-Assisted Liquid-Phase Microextraction.

A method of high-throughput determination, which is based on ultrasound-assisted liquid-phase microextraction, was developed to measure directly the partition coefficients of n-octanol-water. In ultrasound-assisted liquid-phase microextraction, ultrasonic energy can facilitate the mass transfer process of six or more microextractors simultaneously. Therefore, high-throughput determination of n-octanol-water partition coefficients can be performed favorably, and the equilibrium time of each microextractor can be decreased effectively. Several experimental parameters including ultrasonic power and frequency, centrifugation conditions, extractant volume and sample concentration were analyzed and optimized at 25°C. Under the optimum conditions, it only takes 2 min to reach extraction equilibrium, and the solutions of sample can be separated by centrifugation in 4 min. After centrifugation, the concentrations in n-octanol phases are analyzed with gas chromatography. The method was further evaluated with eight reference compounds and the findings demonstrated that this method is suitable to determine the partition coefficients of organic compounds accurately and quickly. Next, the method was exploited to measure the partition coefficients of n-octanol-water containing 20 organic compounds, which cover the [Formula: see text] values from 0.05 to 4.36, with comparatively low relative standard deviation (RSD) directly. The results of this study illustrated that the RSD (n = 6) was under 3%.