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Antineoplastic drugs are carcinogens, mutagens, or teratogenic substances, which can pose serious risks to professionals. Concerns about chronic exposure to these hazardous medicinal products (HMPs) have led to their prominence in the EU strategic framework on health and safety at work 2021–2027. To estimate and mitigate human exposure to HMPs, regular monitoring programs and, consequently, reliable, sensitive, multicomponent methods are crucial. In this study, an unconventional liquid-liquid extraction coupled with liquid chromatography–tandem mass spectrometry analysis is proposed to simultaneously identify and quantify seven HMPs of high concern in urine: cyclophosphamide, etoposide, ifosfamide, paclitaxel, megestrol, mycophenolate mofetil, and tamoxifen, the last three for the first time. Recoveries of all drugs from urine samples were close to 100 %, and method detection limits (0.6–4.1 ng/L) were noticeably lower than most previously reported. This novel, non-invasive method for biomonitoring is thus suitable to unequivocally identify the target drugs at the expected trace levels in urine and to infer about workers' exposure. The method contributes to the conception of regular monitoring programs for antineoplastic drugs, in line with recommendations under EU Directive 2004/37/EC. This is especially relevant in Portugal, where neither analytical methods nor exposure data exist due to lack of formal surveillance. • The method will be crucial to perform regular monitoring, as required in the EU. • The novel method is suitable to identify trace levels of 7 drugs in workers' urine. • The method allows to infer workers' exposure to the 7 hazardous medicinal products. • Multiple extraction procedures are avoided by using a polar solvent (acetonitrile). • A multicompound LLE–LC–MS/MS method was developed and validated for biomonitoring. [ABSTRACT FROM AUTHOR]

7α-Hydroxy-4-cholesten-3-one (C4) is the common intermediary of both primary bile acids. C4 is recommended by the British Society of Gastroenterology for the investigation of bile acid diarrhoea (BAD) in patients with chronic diarrhoea. This project aimed to develop and validate an assay to quantitate C4 in serum and assess the stability of C4 in unseparated blood. Accuracy was underpinned by calibrating to quantitative nuclear magnetic resonance analysis. C4 was analysed in a 96-well plate format with a deuterated C4 internal standard and liquid-liquid extraction. Validation followed the 2018 Food and Drug Administration guidelines. To assess C4 stability, healthy volunteers (n=12) donated 8 fasted samples each. Samples were incubated at 20 °C for up to 72 h and retrieved, centrifuged, aliquoted and frozen for storage at different time points prior to C4 analysis. The C4 method demonstrated excellent analytical performance and passed all validation criteria. The method was found to be accurate, precise, free from matrix effects and interference. After 72 h of delayed sample separation, C4 concentration gradually declined by up to 14 % from baseline. However, the change was not significant for up to 12 h. We present a robust method of analysing serum C4, offering a convenient alternative to 75SeHCAT for BAD investigation. C4 was found to decline in unseparated blood over time; however, after 12 h the mean change was <5 % from baseline. Our results suggest C4 is suitable for collection from both primary and secondary care prior to gastroenterology referral. [ABSTRACT FROM AUTHOR]

No carrier added 204,206Bi radioisotopes were produced by alpha induced reaction on Tl2CO3 target. Liquid liquid extraction method using 18-crown-6 dissolved in nitrobenzene and HClO4 was developed for the separation of NCA 204,206Bi from bulk Tl target. Bulk Tl was observed to be extracted by the organic phase at higher HClO4 concentrations leaving NCA Bi radioisotopes in the aqueous phase. At 0.01 M 18-crown-6 concentration with 2 M HClO4, separation factor (STl/Bi) as high as 3.7 × 103 was achieved. The separation experiment was repeated with stable isotopes of Bi and Tl. The extent of separation was monitored by ICP-OES and the results corroborated with radiometric methods. [ABSTRACT FROM AUTHOR]

The feedstock for the process of hydroprocessed esters and fatty acids (HEFA) is being shifted to renewable waste and residues, e.g., used cooking oil (UCO) containing (un)saturated triacylglycerides (TAG), polar substances including diacylglycerides (DAG), monoacylglycerides (MAG) and free fatty acids (FFA), and dimeric/oligomeric products. However, the yield of saturated hydrocarbons during hydroprocessing of refined UCO (r-UCO) can be lowered by the formation of oligomers via double bonds present in unsaturated TAG and via those produced by dehydration of hydroxy groups of MAG and DAG and β-elimination of (un)saturated TAG. Herein we attempted firstly to remove polar substance from the r-UCO through liquid–liquid extraction and secondly to pre-hydrogenate unsaturated fatty acid chains before the main hydroprocessing reaction. The first attempt was effective for reduced oligomer formation in batch-mode experiments but not in continuous-flow ones. The other attempt was to prove very successful in both modes of experiments regardless of the presence of polar substances in r-UCO; thus, continuous-flow hydroprocessing of r-UCO could be sustained for 100 h without oligomer formation. Consequently, coupling pre-hydrogenation with main hydroprocessing is very powerful in maximizing the yield of hydrocarbons from the conversion of r-UCO because removing polar substances is meaningful but not economic. [ABSTRACT FROM AUTHOR]

CFD‐PBM numerical simulation is a powerful tool in the research of droplet swarm behavior. In this work, an artificial neural network (ANN) based droplet breakage frequency function is established based on the directly measured data from our previous studies. Then, the weights and biases of ANN are embedded into the CFD‐PBM code in the form of matrices and vectors. For the first time, a CFD‐PBM‐ANN simulation framework is established. Simulation results are in good agreement with the experimental data under different operation conditions. The cumulative droplet size distribution decreases with the increase of interfacial tension and pulse intensity. It is also found by the simulation that the droplet breakage frequency is relatively high at the edge of disc and doughnut plate, which is accordant with the distribution of turbulent energy dissipation and velocity gradient. [ABSTRACT FROM AUTHOR]

A pre-treatment and analytical procedure for parathion-methyl (PM) in food samples was developed using cyclodextrin-based dispersive liquid-liquid microextraction (CD-DLLME) accompanied by a smartphone digital image colorimetry (SDIC). The extractant used was a green deep eutectic solvent synthesised from hexanoic acid and menthol. Cyclodextrin aqueous solutions were used as the green dispersion solvents to complete the dispersion and extraction process. Thus, a simple, fast, and environmentally friendly pre-treatment method was proposed. PM that was hydrolysed to a yellow product under an alkaline environment, and the colour intensity could be obtained using a smartphone for analysis. PM showed linearity ranging from 0.0020 to 1.0000 mg L−1, with limits of quantification and detection of 0.0020 and 0.0006 mg L−1. This method has been successfully applied in water, juice, tea, and vinegar, with recoveries ranging from 80.4 to 105.7% and relative standard deviation between 1.3 and 3.6%. This method can determine the concentration of PM in different food samples. [ABSTRACT FROM AUTHOR]

Benzene separation from hydrocarbon mixtures is a challenge in the refining and petrochemical industries. The application of liquid–liquid extraction process using ionic liquids (I.Ls) is an option for this separation. The selection of the most appropriate I.L. for this application is a challenging task due to the variety of anion and cation structures. In the current study, the benzene distribution between the aliphatic hydrocarbon-rich and I.L.-rich phases has been evaluated using the Quantitative Structure–Property Relationship (QSPR) method. A dataset comprising of 112 ternary systems (namely, I.L., benzene, and aliphatic hydrocarbon) was compiled after an extensive review of literature. The primary dataset consists of 17 anions, 20 cations, and 12 aliphatic hydrocarbons. Therefore, the impact of the structure of anion, cation, or aliphatic hydrocarbon on the benzene distribution between the aliphatic hydrocarbon-rich and I.L.-rich phases has been investigated. The linear QSPR models were constructed using Multiple Linear Regression (MLR). The statistical evaluation of the final linear model showed that the constructed model (R2 = 0.900) has an acceptable capability to predict the mole fraction of benzene in the I.L.-rich phase. Additionally, non-linear QSPR models were developed using Genetic Programming (GP) and Artificial Neural Network (ANN) machine learning methods. The statistical evaluation of the GP model (R2 = 0.927) and ANN model (R2 = 0.939) showed that non-linear models had slightly higher prediction accuracy compared to the linear model. The final QSPR model was developed using the BELe3 cation descriptor which is a 2D Burden eigenvalues descriptor and HTm anion descriptor which is a 3D GETAWAY descriptor. After model construction, the selected molecular descriptors of anion and cation structures has been interpreted. The results showed that the size and the electronegativity of the atoms in the anion and cation structure are probably important parameters that affect the benzene distribution between the aliphatic hydrocarbon-rich and I.L.-rich phases. Additionally, the anion shape can be considered as an effective parameter in the benzene extraction process. [ABSTRACT FROM AUTHOR]

An ultrasonic-assisted dispersive liquid–liquid microextraction based on deep eutectic solvent was utilised for simultaneous preconcentration and determination of illegal dyes Sudan orange G (SOG) and Sudan red 7B (SR7B) using second derivative ultraviolet spectrophotometry. Under optimised conditions, the limit of detection (0.014 and 0.011 μg mL−1) and linear dynamic range (0.036–0.900 and 0.030–1.000 μg mL−1) with high determination coefficient of 0.9916 and 0.9937 were obtained for SOG and SR7B, respectively. The relative standard deviations of method (n = 3) for intra- and inter-day were obtained as 3.5% and 10.5% for SOG and 5.0% and 9.0% for SR7B. The preconcentration factor for both dyes was calculated as 75 for all experiments. The applicability of the proposed method was investigated in different real samples, including in chilli powder, lipstick, river water and also in well water. A relative recovery percentage of 88–114% was obtained for these samples. Effect of interferences for the model solutions was also examined wherein satisfactory results confirm reasonable selectivity of the proposed method. [ABSTRACT FROM AUTHOR]

In this study, a dispersive liquid–liquid microextraction along with a back-extraction step (DLLME-BE) has been developed for the determination of thre antidepressant drugs (citalopram, sertraline, and venlafaxine) in biological samples prior to HPLC-UV. Briefly, the method involved two main steps: first, a deep eutectic solvent (DES) composed of tetrabutylammonium bromide (TBABr as a dispersive agent) and 1-dodecanol (as the extraction solvent) was decomposed in an aqueous phase and led to in situ dispersion of the organic phase and extraction of analytes.. Second, Air-assisted liquid–liquid microextraction (AALLME) was applied to back-extract analytes into 50 µL of an aqueous acceptor phase while many interferences were not able to extract into the acceptor solution. By performing this developed extraction method, a high sample clean-up was achieved. The maximum efficiency of analytes was obtained based on the optimisation of the main parameters. Validation of the method indicated that the limits of detection (LODs) and limits of quantifications (LOQs) were in the range of 0.7–3.9 µg L−1 and 2.1–9.8 µg L−1 respectively. The extraction recoveries and enrichment factors of analytes were obtained to be in the range of 87.1–99.1% and 89–102, respectively. Finally, the method was utilised for extraction of three antidepressant drugs in water, human urine and plasma samples. [ABSTRACT FROM AUTHOR]

Folic acid is a vitamin which is soluble in water. Folate is a synthetic version of folic acid, one of the B vitamins. Some foods naturally contain folic acid. Folic acid comes in many forms, including oral supplements and fortified foods. Food folate bioavailability was estimated to be 50%, folic acid bioavailability to be 85%, and when taken as a supplement or with food is 100%. Folic acid is extracted from spinach (Spinacia oleracea), lentils (Lens culinaris), asparagus (Asparagus officinalis), chickpea (Cicer arietinum) and cauliflower (Brassica oleracea). The health benefits of different sources, chemical compositions, and nutritional composition were reviewed. The extraction methods maceration, infusion, liquid-liquid extraction, ultrasound-assisted extraction, and tri-enzyme extraction were reviewed. Purification of folic acid from plant extracts can be done using column chromatography, where components are separated. The separated components were preliminarily analyzed using FTIR for functional group analysis and UV for maximum absorbance values. [ABSTRACT FROM AUTHOR]

This study introduces a green approach to sample preparation by applying natural deep eutectic solvents (NADES) to determine phthalates in carbonated soft drinks using high‐performance liquid chromatography with diode array detector (HPLC‐DAD). The method employs hollow fiber‐microporous membrane liquid‐liquid microextraction combined with a 96‐well plate system, utilizing fatty‐acid‐based DES in the pores of the membranes. This methodology substantially reduces the use of organic solvents, and its efficiency is comparable to or better than conventional methods. Fatty acids with chain lengths ranging from 6 to 12 carbons were investigated for the determination of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and benzyl butyl phthalate (BBP). The optimized approach used a NADES of decanoic and nonanoic acids (2:3 molar ratio), with 60 min of extraction and 30 min of desorption in acetonitrile:methanol (1:1 ratio). Limits of detection were reported as 8.2 µg/L for DMP, 7.6 µg/L for DEP and DBP, and 3.0 µg/L for BBP. Intraday precision ranged from 2.2% to 18.6% and inter‐day precision from 8.8% to 18.8%. Relative recovery across 3 levels ranged from 83.1% to 113.5%. The methodology was evaluated by two tools with green metrics to indicate sustainability. Analytes are extracted, quantified, and confirmed as phthalates in two brands of carbonated soft drinks. [ABSTRACT FROM AUTHOR]

The efficient extraction of tianeptine from environmental matrices has been a matter of concern issue due to the amphiphilic ionic organic substance property of tianeptine. A magnesium-iron layered double hydroxide (Mg/Fe-LDH) was successfully synthesized using hydrothermal synthesis and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques. The as-prepared nanocomposite was used as an effective adsorbent to extract tianeptine from water samples via a dispersive solid-phase extraction (DSPE) procedure before high-performance liquid chromatography-ultraviolet detection (HPLC-UV). Experimental parameters affecting extraction efficiency, such as agitation type, pH, absorbent amount, elution solvent type, and absorption/elution time, were studied and optimized. The developed tianeptine analysis method, based on adsorption-release extraction using Mg/Fe-LDH and detection by HPLC-UV, exhibited a wide quantitative linear range of 10 to 1000 μg/L (r2 = 0.9986, p = 2.49 × 10–14) by plotting chromatography peak height versus tianeptine concentration. The limits of detection and quantification were 4.6 and 15 μg/L, respectively. The developed tianeptine analysis method was applied to analyze tianeptine spiked in water samples. An ideal recovery range of 94.1 to 103.5%, with a narrow relative standard deviation of 1.63–4.34%, was obtained. The proposed analysis method, which combined Mg/Fe-LDH-based DSPE with HPLC-UV detection, was reliable for determining tianeptine in environmental water samples. [ABSTRACT FROM AUTHOR]

A rapid and an environmentally friendly method is developed for the microextraction of furan derivatives from transformer oil for their determination by high-performance liquid chromatography with ultraviolet spectrophotometric detection. Various hydrophilic eutectic solvents were studied as extractants to implement vortex-assisted dispersive liquid–liquid microextraction. The results indicate that a three-component eutectic solvent composed of choline chloride, acetic acid, and water achieves the highest recoveries, ranging from 85 to 96%. The rapid spontaneous phase separation eliminated the need in centrifugation. Limits of detection (3σ) were achieved between 1 and 5 µg/L. [ABSTRACT FROM AUTHOR]

Depolymerization and subsequent capture of monomers is of interest for process efficiency and sustainability. Polyamide‐6 (PA‐6) can be depolymerized in aqueous solution using a homogeneous catalyst. To purify the ε‐caprolactam (CPL) monomer and recycle the catalyst, two potential crystallization‐based strategies are studied: direct crystallization from the reaction mixture and liquid‐liquid extraction prior to crystallization. Solubilities in water and promising organic solvents were measured and compared to predictions using perturbed‐chain statistical associating fluid theory (PC‐SAFT) or conductor‐like screening model for real solvents (COSMO‐RS). Detailed solid‐liquid equilibria (SLE) of the CPL/water system were investigated utilizing DSC and PXRD. This work provides an overview of important factors of PA‐6 depolymerization including recycling of tungstophosphoric acid (TPA) and purification of CPL monomers. A first conceptual process design to be further developed is derived. [ABSTRACT FROM AUTHOR]

The fermentation of whole slurry favors the increase in ethanol titers and minimizes water consumption. However, inhibitors accumulate in the liquid fraction pretreatment, reducing fermentation performance. In order to find a way out, the present study proposed an integration between cloud point extraction (CPE) and ethanol production using fiber of green coconut (GCF) as substrate. Triton X-114 was used to detoxify the liquid fraction from acid pretreatment, and optimal operating conditions were obtained by mathematical modeling. The effects of the residual surfactant from the dilute phase of CPE were analyzed in cellulase adsorption tests, enzymatic hydrolysis, and fermentation of acid-pretreated GCF. CPE promoted high removal of furans (86.23–100%) and phenolic compounds (22.79–75.15%), while the sugars migrated to the dilute phase. A neural network model coupled with a genetic algorithm obtained an optimal condition of 2.38% Triton X-114, temperature of 42 °C, pH of 4.3, and 0.55% sodium chloride. The incubation with the CPE dilute phase increased the residual activity from 25.1 to 50.1% and increased the cellulosic conversion from 32.28 to 41.15%. CPE-saccharification and simultaneous fermentation integration boosted the ethanol production to 12.40 g/L, while the untreated whole slurry reached only 6.29 g/L. Because of these results, the CPE emerges as a promising alternative to favor the full use of sugars from lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

Liquid phase microextraction techniques are considered as the miniaturized version of traditional liquid-liquid extraction, which use only several microliters of a proper solvent to extract the analytes from sample. In these methods, the target analytes are migrated into a water-immiscible organic solvent (acceptor phase) from an aqueous sample (donor phase). They are mainly classified into three main groups including (a) single-drop microextraction, (b) dispersive liquid–liquid microextraction, and (c) hollow fiber-liquid phase microextraction. These techniques have been successfully applied to the assessment of different analytes in food samples, pharmaceuticals, beverages, and so on. This review mainly focuses on up-to-date information on the application of liquid phase microextraction techniques in dairy products. The advantages and disadvantages of the developed liquid phase microextraction methods were discussed. [ABSTRACT FROM AUTHOR]

Diuretics are drugs that promote the excretion of water and electrolytes in the body and produce diuretic effects. Clinically, they are often used in the treatment of edema caused by various reasons and hypertension. In sports, diuretics are banned by the World Anti-Doping Agency (WADA). Therefore, in order to monitor blood drug concentration, identify drug quality and maintain the fairness of sports competition, accurate, rapid, highly selective and sensitive detection methods are essential. This review provides a comprehensive summary of the pretreatment and detection of diuretics in various samples since 2015. Commonly used techniques to extract diuretics include liquid-liquid extraction, liquid-phase microextraction, solid-phase extraction, solid-phase microextraction, among others. Determination methods include methods based on liquid chromatography, fluorescent spectroscopy, electrochemical sensor method, capillary electrophoresis and so on. The advantages and disadvantages of various pretreatment and analytical techniques are elaborated. In addition, future development prospects of these techniques are discussed. HIGHLIGHTS: Pretreatment and determination methods of diuretics in diverse samples are reviewed. Applications of novel materials and technologies for SPE and sensors are highlighted. Pros and cons of recent pretreatment and analysis techniques used for diuretics are discussed. Applications of high-resolution mass spectrometry are described in detail. [ABSTRACT FROM AUTHOR]

In this study, accurate and sensitive determination of ibuprofen in blood, urine, pharmaceutical tablet, syrup, and water samples was accomplished with the combination use of deep eutectic solvent-based ultrasound-assisted liquid–liquid microextraction (DES-UA-LLME) and high-performance liquid chromatography-ultraviolet visible detection system. The most important advantage of this method is that it can be used in the determination of ibuprofen without affecting the matrix environment of a wide range of samples. Ibuprofen in the sample phase was extracted to 500 µL of deep eutectic solvents phase (ChCl:Ph at 1:4 molar ratios) at pH 3.0. The influence of analytical parameters, such as pH of sample solution, the molar ratio of deep eutectic solvents components, tetrahydrofuran volume, and volume of DESs, were optimised in details. The preconcentration factor (PF), the detection limit (DL), intraday, and interday relative standard deviations (RSD, %) for the developed DES-UA-LLME/HPLC procedure were found as 30, 0.4 µg L−1, 1.74%, and 4.68%, respectively. The developed DES-UA-LLME was successfully used for the determination of ibuprofen in urine, blood, pharmaceutical tablet, syrup, and water samples. [ABSTRACT FROM AUTHOR]

An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of nobiletin and tangeretin in rat plasma, and the plasma was processed by a simple liquid-liquid extraction method with ethyl acetate. The chromatographic column was UPLC HSS T3 (50 × 2.1 mm, 1.7 μm), the mobile phase was acetonitrile-water (containing 0.1% formic acid). Multiple reaction monitoring mode (MRM) was used for quantitative analysis, nobiletin m/z 403.29 → 373.14 (cone voltage 22v, collision voltage 28v), tangeretin m/z 373.28 → 343.17 (cone voltage 20v, collision voltage 28V), tangeretin m/z 373.28 → 343.17 (cone voltage 20V, collision voltage 28V) and internal standard vitexin m/z 433.14 → 313.03 (cone voltage 32v, collision voltage 26v). The pharmacokinetics of nobiletin and tangeretin were evaluated in rats. The established UPLC-MS/MS method in the range of 2–2,000 ng mL−1 was successfully applied to the pharmacokinetics, and the calculated bioavailability of nobiletin and tangeretin was 63.9 and 46.1%, respectively. [ABSTRACT FROM AUTHOR]

Explosive-detecting canines (EDCs) show high sensitivity in detecting explosives that they are trained to detect. The ability of canines to detect explosive residues to the parts per trillion level can sometimes result in nuisance alerts. These nuisance alerts can occur when various materials (i.e., substrates) are exposed to volatile organic compounds (VOCs) present in explosive mixtures, leading to contamination—the unintended absorption or adsorption of VOCs by the substrate. Chemical constituents such as taggant, plasticizer, and residual solvent in explosives are often composed of VOCs that canines are trained on to detect explosives. Composition C-4 (C4) is a common explosive that EDCs are trained to detect and hence is this study's focus. Common VOCs of interest emitted from C4 include 2,3-dimethyl-2,3-dinitrobutane (DMNB), 2-ethyl-1 hexanol (2E1H), and cyclohexanone. In this study, we developed a protocol for comparing different substrates such as cotton, cardboard, wood, sheet metal, and glass that were exposed to volatiles from C4. 1-bromooctane (1-BO) was used as a single-odor compound to compare the complex odor originating from C4. Triplicates of substrates such as cotton, wood, cardboard, sheet metal, and glass were exposed to 1 g of C4 in a paint can for one week and the substrates were then extracted using various extraction methods such as liquid injection, direct SPME, and headspace analysis coupled with gas chromatography–mass spectrometry. An extraction time study was performed to determine the optimal extraction time for SPME analysis, and it was found to be 20 min. Comparison of extraction methods revealed that SPME surpassed other techniques as DMNB was found on all substrates using SPME. It was observed that porous substrates such as wood and cardboard have a higher retention capacity for volatiles in comparison to non-porous substrates such as sheet metal and glass. Finally, swabbing was evaluated as a sampling technique for the substrates of interest and the extracts were analyzed using the total vaporization–solid phase microextraction (TV-SPME) technique. No volatiles associated with C4 were identified on conducting a GC-MS analysis, suggesting that swabbing is not an ideal technique for analysis of substrates exposed to C4. [ABSTRACT FROM AUTHOR]

Although annular centrifugal contactors (ACCs) have been widely applied, their complex operation and its dependence on operational variables are still not fully quantified. That hinders their acceptance and precludes revealing their potential. Intuitive techniques to informedly operate ACCs while maximizing their gain are thus demanded. This work introduces a procedure to define the operation window of an extraction task on ACCs, using CINC V 02 variant, that demonstrates the feasible ranges of the operational variables and the maximum possible throughput. The overlapping impacts of the variables are also visualized, thus understood and, to enhance practicality, the procedure is converted into user‐interface software. The concept is intended to adapt to any task on ACCs and it is based on merging a hydraulic part focusing on the rotor and a statistical one modeling the annulus mass transfer. Additional insights on ACC's hydraulics and mass transfer dynamics are presented, including the time needed to establish the steady state. [ABSTRACT FROM AUTHOR]

No-carrier-added (NCA) 161 Tb, which has advisable nuclear properties to be applied for cancer radiotherapy was produced at the Egyptian Second Research Reactor (ETRR-2) by neutron irradiation of natural gadolinium target via indirect nuclear reaction. The radiochemical separation of 161 Tb from irradiated gadolinium target was investigated based on solvent extraction technique using Cyanex 302. Several separation parameters were checked and optimized. According to the obtained results, the separation process of the investigated radioisotopes proceeds in two steps. The first step is an extraction of all of them into the organic phase in which the extraction % (98 %) was optimized at pH 4, 0.15 M of Cyanex 302 and 2.5 h extraction time. Moreover, the slope analysis method confirmed the participation of 2 mol of the organic extractant for the separation of 161 Tb from irradiated gadolinium. The second step is the separation of the 161 Tb isotope that was purified by the stripping of 159Gd with a citrate solution at pH 9, which is considered as a highly efficient and promising method for separation and purification of the two radioisotopes. [ABSTRACT FROM AUTHOR]

The International Maritime Organization (IMO) has implemented new sulfur content regulations for marine fuels in response to growing environmental concerns, including global warming. These regulations severely and costly restrict refinery operations. Oxidative desulfurization (ODS) is an attractive desulfurization method that has advantages such as mild operating conditions and a hydrogen-free process over traditional processes such as hydrodesulfurization (HDS). One can employ oxidative desulfurization in addition to or instead of hydrodesulfurization. Organic sulfur molecules undergo oxidative desulfurization, which results in the formation of polar sulfones. The refined fuel oil is then separated from the oxidized sulfones using methods such liquid-liquid extraction, distillation, and absorption. This work examines and simulates the process of separating sulfur-containing oxidized chemicals from fuel oil utilizing oxidative desulfurization technology. Acetic acid served as the catalyst and hydrogen peroxide as the chosen oxidant. This effort involved simulating the oxidative desulfurization of fuel oil and then using absorption methods to separate the oxidized sulfones. Subsequent procedures including absorption and distillation were used to separate and recover the resultant effluent, solvent, and oxidant from the remaining components. According to the simulation results, the procedure was run at 80 °C and a modest pressure of less than 5 bar. Sulfur content in the original hydrocarbon fuel was 3.5% by weight; at the output, it was less than 0.5% by weight. The findings of the sensitivity analysis of a few key factors demonstrated that the conversion percentage increased from 84 to 98% when the reactor's diameter was changed from 0.5 to 1.2 m and its length was extended to the desired amount. The reaction conversion percentage has increased significantly when the mass flow rate of hydrogen peroxide is increased from 0.5 to 1.5 kg/h, the pressure is increased from 1.5 to 5 bar, and the temperature is raised to 30 °C. According to the process optimization data, the ideal state had an exergy efficiency of 55.57%, a solvent waste rate of 1.75%, and a sulfur content of 0.22% in the fuel. [ABSTRACT FROM AUTHOR]

Anions play an important role in our life, from storing our genetic code on the polyanion DNA, to being the active ingredient in agricultural fertilisers and other industrial processes. Consequently, chemists have been designing systems that can sense anionic species through a variety of methods, such as unimolecular chromophores or sensor arrays. Nonetheless, most existing sensing approaches still have some drawbacks, particularly related to obtaining adequate selectivity and achieving sensing of anions in aqueous environments. In this manuscript, we report a liquid–liquid extraction (LLE)-based sensing approach that allows the conversion of non-selective optical anion sensors that only work in organic media, into selective sensing systems that allow detection of anions in water. We tested this approach on deprotonation-based anion sensors (alizarin, naphthol AS, 4-nitrophenol, BI-Lawsone, and chromophore 1) and hydrogen bonding-based anion sensors (1,2-diaminoanthraquinone and 4-nitro-1,2-phenylenediamine). In general, the deprotonation-based sensors could be converted from a non-selective sensor for basic anions (NCO¯, H2PO4¯, AcO¯ and F¯) to a selective sensing system for NCO¯ with the aid of carefully chosen tetraalkylammonium salts as extracting agents. On the other hand, the hydrogen-bonding based sensors could be converted to a selective sensing system for the hydrophobic anion ClO4¯ using similar tetraalkylammonium salts. [ABSTRACT FROM AUTHOR]

An innovative method for the quantification of corticosterone in the urine of C57BL/6J mice by liquid chromatography-electrospray ionization-tandem mass spectrometry was developed. Unconjugated and glucuronidated corticosterone was detected in the urine samples using enzymatic hydrolysis following liquid–liquid extraction. After optimization of the extraction protocol and LC-MS/MS parameters, we performed a validation study using a representative urine pool of C57BL/6J and Naval Medical Research Institute mice. The method shows good linearity (1–5000 fmol/µL) and the calculated limit of quantification amounts to 0.823 fmol/µL. Both intra-day and inter-day variation was ≤10%, while their recoveries amounted to 90.4–110.6% and 99.8%, respectively. Twenty-four hour urine collection of C57BL/6J mice restrained in two different metabolic cage types for two times was used to test the validated method. To control the hydration level of mice, the corticosterone concentration in their urine was normalized to urinary creatinine concentration. Our LC-MS/MS method represents a highly specific analytical tool for the quantification of corticosterone levels in urine samples, assisting in non-invasive monitoring of acute stress levels in laboratory mice. [ABSTRACT FROM AUTHOR]

The measurement of selected norepinephrine metabolites, such as 3,4-dihydroxyphenylglycol (DHPG), 3-methoxy-4-hydroxyphenylethylenglycol (MHPG), and vanillylmandelic acid (VMA), in biological matrices—including urine—is of great clinical importance for the diagnosis and monitoring of diseases. This fact has forced researchers to evaluate new analytical methodologies for their isolation and preconcentration from biological samples. In this study, the three most popular extraction techniques—liquid-liquid extraction (LLE), solid-phase extraction (SPE), and a new 3D-printed system for dispersive solid-phase extraction (3D-DSPE)—were investigated. Micellar electrokinetic chromatography (MEKC) with a diode array detector (DAD) at 200 nm wavelength was applied to the separation of analytes, allowing for the assessment of the extraction efficiency (R) and enrichment factor (EF) for the tested extraction types. The separation buffer (BGE) consisted of 5 mM sodium tetraborate decahydrate, 50 mM SDS, 15% (v/v) MeOH, 150 mM boric acid, and 1 mM of 1-hexyl-3-methylimidazolium chloride (the apparent pH of the BGE equaled 7.3). The EF for each extraction procedure was calculated with respect to standard mixtures of the analytes at the same concentration levels. The 3D-DSPE procedure, using DVB sorbent and acetone as the desorption solvent, proved to be the most effective approach for the simultaneous extraction and determination of the chosen compounds, achieving over 3-fold signal amplification for DHPG and MHPG and over 2-fold for VMA. Moreover, all extraction protocols used for the selected norepinephrine metabolites were estimated and discussed. It was also confirmed that the 3D-DSPE-MEKC approach could be considered an effective tool for sample pretreatment and separation of chosen endogenous analytes in urine samples. [ABSTRACT FROM AUTHOR]

Aqueous two-phase systems (ATPS) can be described as an alternative to traditional liquid-liquid extraction systems, typically consisting of a polymer and a salt solution. An alternative polymer called polyvinylpyrrolidone (PVP) has emerged as a viable option for ATPS due to its low cost, stability, and potential. This study aimed to investigate the effect of the molecular weight of poly (vinylpyrrolidone) (PVP) (K17, K25, and K30) and the temperature (298.15, 303.15, and 308.15 K) in the system ATPSs composed of PVPs and sodium sulfate/potassium sulfate/tri sodium citrate. The tie-line data were determined by measuring the density (ρ) and refractive index (nD). Moreover, the phase compositions and plait point are investigated for different PVPs molecular weight, temperature, and salt type. In addition, the effect of these parameters on the binodal curve, tie-line length (TLL), and slope of tie line (STL) are analyzed in detail by comparing them with the literature data. The impact of the parameters on the binodal curves was investigated by utilizing the values of the effective excluded volume parameter (EEV) that were calculated from the LLE data. Furthermore, the binodal curves and the tie-line compositions were well-fitted by using some semi-empirical equations. The phase separation ability is enhanced with temperature and PVPs molecular weight. The modified UNIFAC-NRF is used to correlate the liquid-liquid equilibrium data of the studied systems and the optimized binary group interaction parameters were determined. [ABSTRACT FROM AUTHOR]

AbstractMethaqualone, introduced in the 1960s as a sedative-hypnotic alternative to barbiturates, was withdrawn from the market due to its side effects and growing recreational use. Despite this, interest in methaqualone and its analogs remains high, raising concerns about potential abuse in the future. An ultra-high-performance liquid chromatography method coupled with triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS) was developed to determine nine methaqualone-related compounds simultaneously. Biological samples were prepared using liquid–liquid extraction with ethyl acetate at pH9; quantification was performed in blood using multiple reaction monitoring (MRM) mode. Methaqualone-d7 served as an internal standard. The limit of quantification (LOQ) ranged from 0.1 to 0.2 ng/mL, with precision and accuracy within 20%. Recovery ranged from 84.2% to 113.7%. The developed method allowed chromatographic separation of all compounds tested, including two structural isomers: methylmethaqualone and etaqualone. The mass spectra acquired from quadrupole time-of-flight mass spectrometer allowed for the elucidation of comprehensive fragmentation study of methaqualone derivatives. The described situation poses a significant problem from the analytical point of view, as well as interpretation and forensic toxicological expertise. The developed method will contribute to increased analytical capabilities and enhanced detection of compounds from the methaqualone group that may appear on the illicit market. [ABSTRACT FROM AUTHOR]

This study presents a novel and efficient method for determining of cyclobenzaprine (CBP) in human plasma and tablets using simple liquid–liquid microextraction and ultra-high performance liquid chromatography-diode-array detector. The developed method was optimized and validated for selectivity, linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). The chromatographic separation was achieved using a C18 column with a mobile phase consisting of a mixture of deionized water containing 0.1% TFA and methanol (30:70, v:v) at a flow rate of 1.0 mL/min. The extraction process provided high-efficiency recovery of CBP with a small plasma volume (%94.3). The method showed good linearity within the concentration range of 0.005–10 μg/mL, with a correlation coefficient of 0.999. The LOD and LOQ values were found to be 0.0013 and 0.005 μg/mL, respectively. The intra- and inter-day %RSD were <8%, and %RE were ranged from −0.50 to 0.01%. The proposed method was successfully applied to the analysis of CBP in real human plasma samples and tablets, indicating its applicability in clinical and pharmaceutical research. In conclusion, the simple, low cost, high sensitivity and rapid nature of this method make it an attractive option for the quantification of CBP in human plasma and pharmaceutical dosage forms. [ABSTRACT FROM AUTHOR]

This study aims to develop and validate a robust analytical method for the quantification of polybrominated diphenyl ethers (PBDEs) in human serum using gas chromatography–tandem mass spectrometry. We compared procedural blanks, recoveries, and operational convenience of liquid–liquid extraction and supported liquid extraction for the determination of serum PBDEs. We evaluated different extraction solvents for their effect on PBDE recoveries. Supported liquid extraction was selected for method validation due to its operational convenience. The method demonstrated satisfactory linearity, sensitivity, and reproducibility, with the range of 0.10–5.00 µg/L for most PBDE congeners and 0.20–10.0 µg/L for PBDE‐154 and PBDE‐183, with limits of detection ranging from 2 to 48 ng/L, and with matrix effects ranging from 94% to 113%. Quality control assessments indicated that recoveries ranged from 85% to 110% and relative standard deviations of less than 11%. The proposed method was applied to biomonitoring of 111 healthy adults, revealing detectable levels of PBDEs in over 90% of the samples. BDE‐47 and BDE‐183 were the most prevalent, with mean concentrations of 4.13 and 22.1 ng/L, respectively. Detection frequencies ranged from 0.90% for BDE‐17 and BDE‐85 to 25.2% for BDE‐47. Males had higher mean concentrations of BDE‐183 than females. [ABSTRACT FROM AUTHOR]