Vortex-assisted Liquid-liquid Microextraction Research Articles

In-Syringe Vortex-Assisted Liquid-Liquid Microextraction Based on Natural Deep Eutectic Solvent for Simultaneous Determination of the Two Anticancer Polyphenols Chrysin and Resveratrol.

The simultaneous determination of multiple anticancer drugs in combination therapy poses a significant analytical challenge due to their complex nature and low concentrations. In this study, we propose an in-syringe vortex-assisted liquid-liquid microextraction (IS-VA-LLME), based on a green natural deep eutectic solvent (NaDES) for the simultaneous determination of two coadministered anticancer drugs (resveratrol and chrysin) prior to the HPLC-UV analysis, for the first time. The key parameters affecting the extraction efficiency, such as extraction solvent, vortex time, pH, and ionic strength were optimized. Under optimal conditions, the method demonstrates good linearity over the range of 0.05-15.0 μg/mL for RVT and 0.50-15.0 μg/mL for CHR with low limits of detection (LODs) of 16.78 and 161.60 ng/mL for RVT and CHR, respectively, confirming the high sensitivity of the method. The interday and intraday precision values, expressed as %RSDs, are below 2.0%, indicating good repeatability and reproducibility. Furthermore, the proposed method could be efficiently applied for the determination of the two drugs in human plasma and river water. The obtained results show satisfactory % recoveries (97.80%-102.04%), highlighting the accuracy and reliability of the developed method. The sustainability of the method was comprehensively evaluated using seven different tools. In conclusion, the developed IS-VA-LLME-NaDES allows for enhanced extraction efficiency, reduced extraction time, and improved recovery of the target analytes. This method holds great promise for applications in clinical and environmental research, enabling the precise quantification of these anticancer drugs in complex matrices.

A green procedure for the determination of bioavailable forms of aluminum in natural waters by electrothermal atomic absorption spectroscopy combined with microextraction technique.

Aluminum is a prevalent element in nature, but bioavailable forms of aluminum are toxic to plants, animals, and humans. The present study is dedicated to the development of an ecologically friendly, fast, simple, reliable, sensitive, and accurate improved procedure for the determination of subtrace concentrations of bioavailable forms of aluminum in natural waters. The procedure includes the separation and pre-concentration of bioavailable forms of aluminum using vortex-assisted liquid-liquid microextraction (VALLME) of ionic associates with salicylaldehyde 4-picolinhydrazone (SAPH) and sodium dodecyl sulfate (DDSNa) by isoamylacetate (200μl) and direct electrothermal atomic absorption spectroscopy (ETAAS). The SAPH reagent interacts only with water-soluble forms of aluminum. SAPH is used for the pre-concentration of bioavailable forms of aluminum as well as a chemical modifier; it increases the absorbance and the precision of the analytical signal of aluminum. The calibration curve shows the linear dependence in the range of 0.05-86μg⋅L-1 of the aluminum concentration (R2 = 0.992), with the limit of detection at 0.015μg⋅L-1 and the limit of quantification at 0.05μg⋅L-1. The accuracy of the proposed procedure for bioavailable forms of aluminum determination was verified on model solutions and against a reference method on natural samples of river and lake waters (RSD 3.2-5.2%, recovery 97.1-103.4%).

Extraction of phenolic acids and tetramethylpyrazine in Shanxi aged vinegar base on vortex-assisted liquid-liquid microextraction-hydrophobic deep eutectic solvent: COSMO-RS calculations and ANN-GA optimization

In this study, vortex-assisted liquid-liquid microextraction (VA-LLME) based on hydrophobic deep eutectic solvents (HDES) was used to efficiently and sustainably extract five phenolic acids and tetramethylpyrazine (TMP) from Shanxi aged vinegar (SAV). The VA-LLME technique was employed to investigate the extraction mechanism of HDES with the best extraction performance for the target compounds using a conductor-like screening model for real solvents (COSMO-RS). An artificial neural network combined with a genetic algorithm (ANN-GA) was developed to optimize the extraction conditions based on single-factor and response surface methodology, while also analyzing the interactive effects on the phenolic acids and TMP in the extracted solution during the extraction phase. The optimized conditions were determined, and the greenness of the procedure was evaluated using an analytical greenness metric, indicating that this technique can serve as a green alternative for the determination of phenolic acids and TMP in SAV.

An Innovative Vortex-Assisted Liquid-Liquid Microextraction Approach Using Deep Eutectic Solvent: Application for the Spectrofluorometric Determination of Rhodamine B in Water, Food and Cosmetic Samples.

A new green and highly sensitive method for the determination of rhodamine B (RhB) by deep eutectic solvent-based vortex-assisted liquid-liquid microextraction with fluorescence detection (DES-VALLME-FLD) was developed. The extraction efficiency of conventional solvents and different deep eutectic solvent (DES) systems composed of tetrabutylammonium bromide (TBAB) and an alcohol (hexanol, octanol, or decanol) in different ratios were compared. DFT calculations of intermolecular electrostatic and non-covalent interactions of the most stable RhB forms with DES and water explain the experimental DESs' extraction efficiency. Semiempirical PM7 computations were used to obtain Hansen solubility parameters, which supported the good solubility of the monocationic RhB form in selected DESs. The dependence of the linear calibration of microextraction into 100 µL DES was observed in the RhB calibration range from 0.2 to 10.0 µg L-1 with a correlation coefficient of R2 = 0.9991. The LOD value was calculated to be 0.023 µg L-1. The accuracy and precision of the proposed method were verified over two days with RSD values of 2.9 to 4.1% and recovery of 94.6 to 103.7%. The developed method was applied to the determination of RhB in real samples (tap water, energy drink, and lipstick).

Simultaneous Determination of 8 Antioxidants and Free Sulfur Migrating from Container Closure System into Antibody Drug using High Performance Liquid Chromatography

<p>Background: The additives from container closure systems used in biopharmaceuticals, including antioxidants and vulcanizing agents, may leach into drug products during production or storage and result in patient exposure. Thus, there is an urgent demand for developing a robust and sensitive method for the simultaneous determination of these additives. </p> <p> Method: An approach utilizing vortex-assisted liquid-liquid microextraction coupled with highperformance liquid chromatography has been developed for the simultaneous determination of 8 antioxidants and free sulfur in biopharmaceutical samples. The extraction parameters, such as the choice of extraction solvent, HCl volume, vortex time, and disperser solvent, were optimized to ensure maximum extraction efficiency. </p> <p> Results: The optimized method was validated successfully, exhibiting acceptable recovery rates ranging from 89.2% to 109.0%, excellent repeatability (2.9% to 5.1%, n=6), and intermediate precision (3.7% to 5.9%, n=12), and satisfactory linearity with an R2 value of 1.000 for all the additives. Additionally, the limits of detection and quantification were determined to be in the range of 1.9– 30.0 μg/L and 7.5–120.0 μg/L, respectively. </p> <p> Conclusion: The proposed method was effectively applied to the analysis of additives in biopharmaceutical samples.</p>

Novel ferrofluid based on hydrophobic deep eutectic solvents for separation and analysis of trace estrogens in environmental water and urine samples.

A novel ferrofluid prepared from ahydrophobic deep eutectic solvent (DES) and Fe3O4@graphite composite materials was introduced as a green microextraction medium for the separation and enrichment of trace estrogens in real samples. It was found that the ferrofluid greatly improved the capacity and selectivity of target analytes, benefiting from the enrichment of both DES and Fe3O4@graphite composite materials. Using a combination of high-performance liquid chromatography-fluorescence detection (HPLC-FLD) and vortex-assisted liquid-liquid microextraction (VALLME), a new method was established for simultaneous rapid processing and accurate determination of three estrogens (estradiol [E2], estriol [E3], and ethinyl estradiol [EE2]) in environmental water and urine samples. Key parameters affecting the extraction efficiency were optimized using a single-factor approach and response surface methodology. Under optimal conditions, this method yielded a low limit of detection (1.01 ng L-1, 3.03 ng L-1, and 25.0 ng L-1 for EE2, E2, and E3, respectively), wide linear range (3-200,000ng L-1), high enrichment factors (9.81-47.2), and satisfactory recovery (73.8-129.0%). Compared with traditional analytical techniques, this method avoids the use of volatile toxic organic extraction solvents and cumbersome phase separation operations.

Determination of fifteen illegal colorants in traditional Chinese medicines by two hydrophobic DES-based microextraction methods coupled with an HPLC-DAD

The dyeing and adulteration of traditional Chinese medicines (TCMs) are continuously updated. Valuable analytical methods for the daily inspection of illegal colorant additives in TCMs and the preparations are in demand. Two deep eutectic solvent (DES)-based vortex-assisted liquid-liquid microextraction (VA-LLME) and ultrasonic-assisted solid-liquid microextraction (UA-SLME) were developed for the sample pretreatment of ten water-soluble colorants and five water-insoluble colorants, respectively, followed by an HPLC-DAD detection. Fifteen colorants were analyzed at four detection wavelengths within 40 min of gradient elution. The optimal DES of VA-LLME and UA-SLME were screened from 23 homemade DESs. The factors affecting the extraction efficiency of VA-LLME and UA-SLME were optimized systematically. Under the optimal conditions, ten water-soluble colorants analyzed by DES-based VA-LLME-HPLC-DAD showed good linearity (R ≥ 0.9995) within the optimal linear range. The LODs and LOQs were 0.2–1.0 μg g−1 and 0. 5–5.0 μg g−1, respectively. The recoveries of spiked samples were 80.2%–104.7 %, with RSDs ≤ 4.39 %. Five water-insoluble colorants of Sudan I‒IV and Sudan 7B analyzed by DES-based UA-SLME-HPLC-DAD showed good linearity (R ≥ 0.9995) within the optimal linear range. The LODs and LOQs were 0.8–8.0 μg g−1 and 4.0–40.0 μg g−1, respectively. The recoveries of spiked samples were 94.2%–103.1 %, with RSDs ≤ 4.81 %. The proposed DES-based VA-LLME-HPLC-DAD was successfully applied to analyze six water-soluble yellow colorants in Cuscutae Semen, salted Cuscutae Semen, and four water-soluble red colorants in Schisandrae Chinensis Fructus. The proposed DES-based UA-SLME-HPLC-DAD was successfully applied to analyze five water-insoluble red colorants in Dieda pills. The study provides analytical method options for routine tests of water-soluble, water-insoluble, or both water-soluble/-insoluble illegal colorant additives in herbal medical materials and preparations by the relevant proposed DES-based sample pretreatment method or a combination of the two proposed DES-based methods.

Extraction of 5 benzotriazole ultraviolet filters from soil samples using natural deep eutectic solvent vortex assisted liquid–liquid microextraction combined with GC–MS

Benzotriazole (BTRs) ultraviolet filters are a class of substances found in the environment that pose potential hazards to human health and environment. Therefore, it is essential to develop techniques for determining BTRs in the environment. In this paper, a simple, green, and effective vortex assisted liquid–liquid microextraction (VALLME) was developed to determine trace BTRs in the environment, combining natural deep eutectic solvents (NADES) with Gas chromatography-mass spectrometer (GC–MS). Result parameters were optimized by single factor analysis, Factorial Multilevel Categoric Design and Central Composite Design, and optimal extraction solve (NADES) was obtained by mixing choline chloride (ChCl) and lactic acid (LA) with the ratio 1:1. After optimization, the linearity (r2 ≥ 0.9929), LODs (0.010–0.083 μg/ml), LOQs (0.033–0.276 μg/ml), and RSD (2.96–4.21 %) were verified. For the first time, a method based on the new type of NADES for the determination of BTRs ultraviolet filters in soil was propose, which could replace traditional extractants for BTRs and serve as a sustainable and environmentally friendly extraction medium for other matrices.

Highly efficient natural deep eutectic solvent-based liquid-liquid microextraction and inductively coupled plasma mass spectrometry for selective determination of inorganic selenium species in nut samples

A novel method involving the use of a hydrophobic natural deep eutectic solvent (NADES) in the vortex-assisted liquid-liquid microextraction technique based on the solidification of floating NADES for inorganic Se speciation analysis was developed. In this work, Se(IV) species was selectively complexed with ammonium pyrrolidinedithiocarbamate (APDC) and extracted with 50 μL of the NADES thymol:decanoic acid (THY:DA) (1:2) followed by fast phase separation upon freezing. Se(VI) species remaining in the aqueous phase was directly determined by inductively coupled plasma mass spectrometry (ICP-MS) while total inorganic Se concentration was determined by direct analysis of the acidic extract originated from the samples. Therefore, Se(IV) was calculated by subtracting the concentration of Se(VI) from the total inorganic Se concentration. Extraction conditions such as pH, sample volume, and type and volume of NADES were optimized, yielding an extraction efficiency of 99.6% for Se(IV). Limits of detection of 0.31 μg L−1 for Se(IV) and 0.24 μg L−1 for Se(VI), relative standard deviations of 3.5% for Se(IV) and 3.0% for Se(VI) and a linear range of 0.78–1000 μg L−1 were obtained. This work reports the first application of the NADES THY:DA (1:2) for the separation and determination of Se species in complex matrix samples such as almond, hazel nut, peanut, walnut, cashew nut, pecan nut and Brazil nut.

Deep eutectic solvent-based ferrofluid for vortex-assisted liquid-liquid microextraction of nonsteroidal anti-inflammatory drugs from environmental waters

A novel ferrofluid of Fe3O4 nanoparticles and a deep eutectic solvent (DES) composed of menthol and pentanoic acid was introduced as a green microextraction medium. The ferrofluid was successfully used as an extractant for vortex-assisted liquid-liquid microextraction (VALLME) of nonsteroidal anti-inflammatory drugs (NSAIDs) in environmental waters prior to their determination by HPLC-DAD. Once the ferrofluid was dispersed in the sample by vortex agitation, phase separation could be easily achieved by placing a neodymium magnet next to the tube, which eliminated the centrifugation step and simplified the operational procedure. As a result, the sample pretreatment took only ≈2 min. The experimental parameters, including pH, nanoparticle amount, ferrofluid volume, vortex time, salt amount, and disruptive solvent type and its volume, were optimized stepwise. The method showed linear behavior for all NSAIDs from 5 to 100 μg/L, with limit of detection values and enrichment factors in the ranges of 1.68–2.05 μg/L and 38.9–50.6, respectively. Intra- and Inter-day accuracies obtained from the analysis of spiked river, lake, and tap water samples at low and high-quality control levels (20 and 80 μg/L) ranged from 90.3% to 108.0%, with relative standard deviations less than <12.3%. The results of this study demonstrate that the use of DES-based ferrofluid in VALLME can be considered a simple, environmentally friendly, and reliable alternative for the determination of NSAIDs in environmental waters.

Selective extraction of anionic and cationic dyes using tailored hydrophobic deep eutectic solvents

In this work, eight kinds of hydrophobic deep eutectic solvents (DESs), including four types of ionic and four types of non-ionic DESs, were prepared and applied in vortex-assisted liquid-liquid microextraction (LLME) technology. To explore the extraction ability of the hydrophobic DESs-based vortex-assisted LLME, four types of dyes were selected as analytes, involving anionic tartrazine (TA), amaranth (AM) and cationic phenosafranine (PF), methylene blue (MB). It turned out that the ionic and non-ionic hydrophobic DESs showed selective extraction on anionic and cationic dyes, respectively. In particular, the extraction efficiency of TA could reach 99.3 % when trioctylmethylammonium chloride-thymol ([TMAC][Thy]) was utilized as extraction agent. The partitioning efficiency of PF was up to 99.9 % by using decanoic acid-thymol ([DecA][Thy]) as extraction agent. The limits of detection (LODs) of TA and PF were 0.06 and 0.14 μg mL−1, respectively. The limits of quantification (LOQs) obtained for TA and PF were 0.20 and 0.47 μg mL−1, respectively. Besides, FT-IR and 1H NMR were utilized to investigate the extraction mechanism. The results demonstrated that the hydrogen bonding and electrostatic force were the main driving forces in the extraction process. Furthermore, through separating various anionic and cationic dyes, the selective extraction ability of [TMAC][Thy] and [DecA][Thy] were successfully verified. Hence, the feasible operation, high extraction efficiency and excellent selectivity make the developed hydrophobic DESs-based vortex-assisted LLME attractive in dyes separation.

Determination of Flavonoid Compounds in Shanxi Aged Vinegars Based on Hydrophobic Deep Eutectic Solvent VALLME-HPLC Method: Assessment of the Environmental Impact of the Developed Method.

This research presents a novel, eco-friendly, vortex-assisted liquid-liquid microextraction (VALLME) approach, integrating hydrophobic deep eutectic solvents (DESs) with HPLC for the identification and quantification of nine specific flavonoids in Shanxi aged vinegar (SAV). The parameters of DES-VALLME, including the ratio of trioctylmethylammonium chloride to 1,4-butanediol (1:6), DES volume (150 μL), vortex duration (5 min), the concentration of NaCl (0.40 g), and centrifugation time (10 min), were optimized to achieve the maximum extraction efficiency of target substances. Under these optimal conditions, quantitative analyses performed via HPLC demonstrated a broad linear range of 0.20-50.00 μg/mL and correlation coefficients (r2) greater than 0.9944 for all nine calibration curves. The limits of detection (LOD) and limits of quantitation (LOQ) were 0.09-0.18 μg/mL and 0.30-0.60 μg/mL, respectively, ensuring high sensitivity. The relative standard deviations for intra-day and inter-day variability were within the acceptable range, 2.34-3.77% and 3.04-4.96%, respectively, demonstrating the method's reliability. The recovery rates ranged from 85.97% to 108.11%, underscoring the method's precision. This technique exhibited a significant enrichment effect (enrichment factor: 43 to 296) on SAV flavonoids. Notably, the eco-friendliness of this procedure was evaluated using the Analytical Eco-Scale, Green Analytical Procedure Index, and Analytical Greenness Metric. The results suggested that this technique is a viable green alternative to traditional flavonoid determination methods in SAV. In summary, this novel method provides a theoretical basis for assessing flavonoid content in SAV samples and tracing SAV products. This contribution has significant implications for enhancing analytical techniques in food chemistry and environmental science and the sustainable development of the food industry.

A hydrophobic deep eutectic solvent-based vortex-assisted liquid-liquid microextraction applied for doping control of aromatase inhibitors from equine urine

Aromatase inhibitors (AIs) can indirectly cause increased testosterone in animals, which leads to the improvement of the athletic ability of horses. For the protection of horses and the consideration of fair competition, AIs were listed as prohibited drugs by the Federation Equestre Internationale (FEI). There were several disadvantages using traditional pretreatment methods before analyzing these drugs from biological samples. A rapid and green pretreatment method has been developed by utilizing the hydrophobic deep eutectic solvent (DES)-based vortex-assisted liquid-liquid microextraction (DES-VALLME) followed by ultra-high performance liquid chromatography tandem triple-quadrupole mass spectrometry (UHPLC-MS/MS) technique for the efficient extraction and sensitive detection of AIs in equine urine samples. The combination of menthol and 4-fluorophenol in a molar ratio 1:4 was chosen as the optimum composition of DES for extracting AIs. Under the optimum conditions, only 80 μL of DES, 1 mL equine urine and 2 min were expended. An external standard calibration method was utilized for determination, and a linear relationship was achieved with a concentration range of 0.02–4000 ng mL−1 (r2 ≥ 0.9983). The limits of detection of the method based on a signal-to-noise ratio of 3 were 0.01–4 ng mL−1. The accuracy recoveries ranged from 94.9% to 113.4% within the intra-day and inter-day relative standard deviations of less than 9.1%. Compared with traditional extraction methods, the DES-VALLME method had the advantages of rapidity, simplicity, efficiency, low toxicity, and low cost. This method has potential and possessed brilliant prospects for doping control.

Assessment of endocrine disruptor pollutants and their metabolites in environmental water samples using a sustainable natural deep eutectic solvent-based analytical methodology

In this work, an evaluation of the occurrence of fifteen phthalates, four metabolites and one adipate in different groundwater, seawater and wastewater samples has been carried out due to their relevance on human health as they act as endocrine disruptors. For this purpose, a sustainable, fast and easy-handling vortex-assisted liquid-liquid microextraction method using a natural hydrophobic deep eutectic solvent based on menthol and carvacrol as extraction agent, combined with ultra-high performance liquid chromatography-mass spectrometry technique, has been developed and applied for the first time. An optimization was performed to evaluate four important factors affecting the extraction performance, and an analytical validation was carried out in terms of matrix effect, linearity, extraction efficiency, and sensitivity. Recovery values were obtained in the range 72–119% for all analytes (except for monoethyl phthalate: 61.1–72.3%) with relative standard deviation values lower than 17%. Limits of quantification were found between 0.91 and 8.09 μg L−1. As a result of the assessment of 31 different environmental water samples, monoethyl phthalate, diethyl phthalate, dibutyl phthalate and bis (2-ethylhexyl) phthalate were detected and quantified at different concentrations in the range 2.59–21.17 μg L−1 in 6 samples, and diallyl phthalate, butyl benzyl phthalate, dipentyl phthalate, dicyclohexyl phthalate, dihexyl phthalate and bis (2-ethylhexyl) adipate were detected in 20 more, showing the exposition of the population to these hazardous substances.

Preparation of a hydrophobic deep eutectic solvent and its application in the detection of quinolone residues in cattle urine.

Enrichment for the detection of quinolone residues is usually cumbersome and requires large amounts of toxic organic reagents. Therefore, this study synthesized a low-toxicity hydrophobic deep eutectic solvent (DES) with DL-menthol and p-cresol, which was then characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and thermal analysis. A simple and rapid vortex-assisted liquid-liquid microextraction method was developed based on this DES for the extraction of eight quinolones from cattle urine. The optimal extraction conditions were screened by examining the DES volume, extraction temperature, vortex time, and salt concentration. Under the optimal conditions, the linear ranges of the eight quinolones were 1 ~ 100μg/L with good linearity (r2 was 0.998 ~ 0.999), and the limits of detection and quantification were 0.08 ~ 0.30μg/L and 0.27 ~ 0.98μg/L, respectively. The average extraction recoveries of spiked cattle urine samples were 70.13 ~ 98.50% with relative standard deviations below 13.97%. This method can provide a reference for the pre-treatment of quinolone residue detection.

Ultra-trace mercury determination in seawater after vortex-assisted liquid-liquid micro-extraction

In the present study, an analytical methodology based on a vortex-assisted liquid-liquid micro-extraction (VALLME) was developed for extraction and enrichment technique of total mercury (Hg) from seawater after derivatisation with ammonium pyrrolidine dithiocarbamate (APDC), while Hg quantitation was performed by atomic absorption spectrometry (AAS) using a Direct Mercury Analyser DMA-80 spectrometer based on thermal desorption. Variables affecting Hg derivatisation (including pH and APDC concentration) and VALLME extraction (comprising extraction (vortex) time, acceptor solvent (hexane) volume and ionic strength of donor phase) were explored. Enrichment factor (EF) and extraction recovery (ER) of 51 and 76 ± 5.3% were obtained from only 20 mL of seawater (at pH = 3) when using an APDC concentration of 0.125 mmol/L, and vortex time and acceptor solution volume of 4 min and 300 μL, respectively; whereas NaCl addition had no effect on Hg determination. The VALLME-AAS method has been high sensitive (quantification limit, QL = 10.3 ng L−1) and precise (with relative standard deviations, RSDs of <14%). The developed procedure has been tested by analysing different sea water (NASS-7) and estuarine water (SLEW-3 and BCR-505) certified reference materials. Finally, Hg levels between 34 and 172 ng L−1 have been assessed in several seawater samples at A Coruña bay.

Analysis, distribution and evolution of individual carboxylic acids in crude oil during biodegradation

Carboxylic acids (CAs) are important molecular markers in the study of petroleum biodegradation. This work presents a vortex-assisted liquid–liquid microextraction (VALLME) method, followed by comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC–MS) analysis for the profiling of CAs in complex oils. The designed extractant containing CAs in VALLME can be silylated immediately and injected into GC × GC–MS without any post-treatment. More than 400 individual CAs, including alkanoic acids, cyclic aliphatic acids and aromatic acids, were putatively or positively identified. With good reproducibility and high sensitivity, VALLME combined with GC × GC–MS was applied to investigate the distribution and evolution of individual CAs in crude oil during laboratory biodegradation. It was found that acyclic acids and monocyclic aliphatic/aromatic acids could be detected at all stages of oil biodegradation, while polycyclic aliphatic/aromatic acids could only be identified in oils at a relatively higher degree of biodegradation. In addition, the contents of each type of CA changed regularly during biodegradation. Targeted analysis on the distributions of individual acyclic acids showed that the abundance ratio of short chain to long chain n-alkanoic acids kept increasing during biodegradation, which might reflect the multiple origins of short chain n-alkanoic acids. Moreover, based on the distributions of pristanic/phytanic acid and pristane/phytane in oils with different biodegradation degrees, pristanic and phytanic acid seemed to be more susceptible to degradation compared to their hydrocarbon analogues, and pristane might be more susceptible to degradation in comparison to phytane.

Inhalation bioaccessibility of multi-class organic pollutants associated to atmospheric PM2.5: Correlation with PM2.5 properties and health risk assessment

Inhalation exposure to fine particulate matter (PM2.5) represents a global concern due to the adverse effects in human health. In the last years, scientific community has been adopted the assessment of the PM2.5-bound pollutant fraction that could be released (bioaccessible fraction) in simulated lung fluids (SLFs) to achieve a better understanding of PM risk assessment and toxicological studies. Thus, bioaccessibility of 49 organic pollutants, including 18 polycyclic aromatic hydrocarbons (PAHs), 12 phthalate esters (PAEs), 11 organophosphorus flame retardants (OPFRs), 6 synthetic musk compounds (SMCs) and 2 bisphenols in PM2.5 samples was evaluated. The proposed method consists of a physiologically based extraction test (PBET) by using artificial lysosomal fluid (ALF) to obtain bioaccessible fractions, followed by a vortex-assisted liquid-liquid microextraction (VALLME) and a final analysis by programmed temperature vaporization-gas chromatography-tandem mass spectrometry (PTV-GC-MS/MS). The highest inhalation bioaccessibility ratio was found for bisphenol A (BPA) with an average of 83%, followed by OPFRs, PAEs and PAHs (with average bioaccessibilities of 68%, 41% and 34%, respectively). Correlations between PM2.5 composition (major ions, trace metals, equivalent black carbon (eBC) and UV-absorbing particulate matter (UVPM)) and bioaccessibility ratios were also assessed. Principal Component Analysis (PCA) suggested that PAHs, PAES and OPFRs bioaccessibility ratios could be positively correlated with PM2.5 carbonaceous content. Furthermore, both inverse and positive correlations on PAHs, PAEs and OPFRs bioaccessibilites could be accounted for some major ions and metal (oid)s associated to PM2.5, whereas no correlations comprising considered PM2.5 major ions and metal (oid)s contents and BPA bioaccessibility was observed. In addition, health risk assessment of target PM2.5-associated PAHs via inhalation was assessed in the study area considering both total and bioaccessible concentrations, being averaged human health risks within the safe carcinogenic and non-carcinogenic levels.

Deep eutectic solvent based-ferrofluid ultrasonic-assisted liquid–liquid microextraction for determination of quinolones in milk samples

In the current study, vortex assisted-liquid–liquid microextraction (VA-LLME) pretreatment method was developed based on superparamagnetic nanofluid and deep eutectic solvents for the isolation and preconcentration of quinolones in milk sample. The deep eutectic solvent-ferrofluid (DES-FF) with high extraction ability was prepared by combining DL-menthol/octanoic acid deep eutectic solvent and magnetic nanoparticles, which was mainly related to the strong interactions between extractant and analytes, such as hydrophobic interactions, hydrogen bonding attractions and electrostatic interactions. The functional group, and magnetic characteristics of the synthesized materials were characterized by using Fourier transform-infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometer. The use of vortex instead of dispersed solvent in LLME is simple and quick, reducing the consumption of solvent and shortening the extraction time. The parameters which affected the extraction efficiency were investigated and optimized using response surface methodology (RSM). Under the optimum conditions, linearity (r > 0.996) was in the range of 1.00–100 μg mL−1. Limit of detection (LOD) and quantification (LOQ) of two quinolones varied in 0.30–0.35 μg mL−1 and 0.80–1.0 μg mL−1, respectively. The recoveries were in the range of 84.4–95.4%, RSD of intra-day and inter-day precision were not higher than 5.0% and 7.7%, respectively. Finally, the developed method was successfully applied for the determination of quinolones in milk.

Vortex-assisted liquid-liquid microextraction combined with liquid chromatography tandem mass spectrometry for simultaneous determination of cardiovascular drugs in human plasma

Hypertension and dyslipidemias are among the main risk factors for the development of cardiovascular diseases, which are responsible for the death of approximately 17 million people each year. There are several drugs available for the treatment of these diseases. Therefore, methods for the simultaneous analysis of several of these drugs are useful in a wide range of situations. In this context, this study aimed to develop a modern method for the simultaneous determination of eight cardiovascular drugs in human plasma. A vortex-assisted liquid-liquid microextraction (VALLME) procedure, combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. Mass spectrometry conditions, chromatographic separation, and sample preparation were optimized. For VALLME optimization, pH, sodium chloride concentration, volume of buffer solution, extraction solvent (type and volume), and vortex stirring time were evaluated. The method proved to be simple, fast, and environmentally friendly since low volumes of organic solvent were employed. Furthermore, the VALLME procedure required small sample volume, which is desirable when large volumes are scarce. Suitable recoveries and lower limits of quantification were achieved with a chromatographic run of only 8 min. The method was validated, showing to be selective, precise, and accurate. Furthermore, the analytical curves were well fitted to the selected models and the matrix effect did not affect method reliability. The developed method was successfully applied for the analysis of plasma samples obtained from volunteers attending a hospital service.