Separations

The separation of mixtures with close boiling points is a critical task in the petrochemical industry, and one such mixture that requires separation is o-xylene/styrene. The STED process is used to separate o-xylene/styrene, which contains a certain amount of organic sulfur in the product due to the limitations of the process. In this study, the process underwent enhancements to attain the effective separation of styrene and accomplish deep desulfurization. A mixture of sulfolane (SUL) and N-methylpyrrolidone (NMP) was selected as the extraction solvent after calculating the UNIFAC group contributions. An orthogonal experiment was conducted to investigate the effects of the solvent/oil ratio, reflux ratio, water addition rate, and solvent ratio on the product. The correspondence between each factor and the indexes examined was determined, enabling the optimization and prediction of the styrene product quality. The final optimized conditions for the extractive distillation column are as follows: solvent/oil ratio of 7, reflux ratio of 4.5, water addition rate of 6000 kg/h, and a solvent ratio of 9:1. Under optimal conditions, the purity of the product was observed to be greater than that of the original process and the sulfur content of the product can be reduced to lower than 10 ppm at the cost of an increase of 12.31% in energy consumption. Full article

The leaves of Catharanthus roseus (L.) G. Don contain a large number of diverse secondary metabolites, making them comparably complex. The Catharanthus genus has received increased interest from scientists in recent years due to its extensive applications in several domains, including the pharmaceutical sector, where precise characterization of its characteristics is required. An effective inquiry technique is needed for chemo-profiling to identify the metabolites in plant samples. The main goal of this research is to provide supplementary data on the chemical composition of the leaves of twenty-five different accessions of C. roseus through the application of gas chromatography-mass spectrometry (GC-MS). The study’s findings reveal the existence of a vast number of phytochemicals, allowing for a comparison of the different accessions. Furthermore, a meticulous statistical analysis of this data using principal components analysis (PCA) and a heatmap, and hierarchical cluster analysis (HCA) may aid in providing more relevant information on C. roseus leaves for possible investigation of their metabolites in further scientific studies. Full article

Semiconductor photocatalysis technology is an environmentally friendly and efficient emerging technology. This method can use sunlight as a driving force to quickly decompose organic pollutants in water bodies. Zinc oxide (ZnO) and tungsten oxide (WO₃) photocatalysts can absorb sunlight and participate in photocatalytic degradation reactions due to their relatively narrow band gap. Highly photosensitive WO₃ nanofibers and ZnO/WO₃ composite nanofibers were fabricated via the electrospinning method. When 100 mg/L of rhodamine B (Rh B) solution was used as the degradation substrate, the degradation efficiencies of WO₃ and ZnO/WO₃ for Rh B dye were 70% and 90%, respectively, after a photocatalytic reaction of 120 min. The surface morphology, crystal structure, and optical properties of ZnO/WO₃ composite nanofibers and WO₃ nanofibers were characterized by SEM, XRD, XPS, and UV-vis absorption spectra, and the experimental results were analyzed and explained using different mechanisms. The results show that ZnO/WO₃ composite nanofibers have better UV-visible light absorption performance, and the sample has a higher UV-visible light utilization rate. This was mainly due to the fact that a P-N heterojunction was formed in the semiconductor composite, and the electron–hole pair could realize rapid separation under the drive of a built-in electric field force, which promoted the migration of carrier. Therefore, the photocatalytic activity of the ZnO/WO₃ catalyst was significantly higher than that of the WO₃ catalyst, which promoted rapid improvement of the photocatalytic degradation efficiency of the Rh B dye. Full article

F. religiosa bark has been extensively used in traditional medicinal systems, such as Ayurveda, for its health benefits. The aim of this study was to investigate the secondary metabolites (phenolics and flavonoids) of the hydroalcoholic stem-bark extract from F. religiosa because this plant has been proven to have a beneficial effect on health disorders. Therefore, a pilot study was conducted for the identification and quantification of polyphenolic compounds in F. religiosa bark using sophisticated chromatographical techniques such as UPLC-HRMS and RP-HPLC-PDA. Additionally, total flavonoids, total phenolics and the scavenging profile of the bark were studied using a UV spectrophotometer. A total of 23 compounds identified with UPLC-HRMS were mainly phenolic acids, polyphenolics, and flavonoids (flavanols and proanthocyanidins). Among the identified compounds, gallic acid, catechin, epicatechin, epigallocatechin gallate, and ellagic acid were simultaneously quantified (0.031–0.380%) using RP-HPLC-PDA. Thereafter, the study complied by evaluating the total flavonoids (109.15 ± 1.2 mg RuE/g and 33.78 ± 0.86 mg CaE/g), total phenolics (4.81 ± 1.01 mg GaE/g), and scavenging profiles (IC₅₀ 13.75 ± 0.12 µg/mL) of the F. religiosa bark. This is the first report on the chemical profiling of F. religiosa bark, which is a necessary step to evaluate its nutraceutical properties, paving the way for possible food application. Full article

Water organic pollution has become a major issue. A large number of people suffer from the decline in water quality. In addition, polluted water can lead to health problems or excessive deaths. In this regard, an increasingly important method for efficient water treatment is electrocoagulation (EC), the technology that encompasses a small equipment size combined with a simple operation compared to other water treatment methods. The importance of EC is especially accentuated by the recent decarbonization efforts due to the increasing availability of renewable electricity systems. This review provides an overview of the most recent developments in EC technology as it pertains to wastewater treatment. The EC is preferred for organic wastewater treatment over other traditional treatment methods due to its easy setup and low material costs. Moreover, the EC is very powerful in destabilizing organic impurities by charge neutralization and then coagulating to form flocs. In addition, EC has shown high efficiency not only in removing various organic pollutants but also in emerging persistent contaminants, such as microplastics. For these reasons, the EC mechanisms and related functional modalities are reviewed, as well as extensive details are provided on the diversity of the removed contaminants. Overall, this review provides significant new knowledge of interest for environmental chemical researchers in particular and engineers in general on the details of the EC technology for wastewater treatment and water purification. Full article

In recent years, the rapid development of the domestic alumina industry has greatly accelerated the consumption of high-alumina–silica-ratio bauxite resources in China. The development of an efficient and clean utilization technology applicable to low-grade bauxite in China is not only a requirement for resource and environmental protection, but also a powerful guarantee to maintain the sustainable development of China’s aluminum industry. Based on this, the authors’ team proposed a new process for the treatment of low-grade bauxite ore via a calcification–carbonization method from the perspective of equilibrium solid-phase reconstruction and achieved the first industrial-scale trial run on the basis of existing laboratory research. The results show that the mass fraction of Na₂O in bauxite residue can be reduced to 0.95% in the treatment of typical diaspore bauxite, the A/S in the bauxite residue can be reduced to 0.85 after two-time carbonization–alumina dissolution, and the actual alumina dissolution rate can reach 81.32%. The relevant results verified the feasibility and advantages of the calcification–carbonization method in industrial production. Full article

Photochemical generation is an important pathway for atmospheric sulfate formation. However, the roles of atmospheric co-existing photosensitive dissolved organic matter (DOM) in sulfate formation are still unclear. The experimental results in this work provide evidence that atmospheric photosensitizers produce active intermediates to oxidize S(IV) into S(VI) under illumination. Quenching experiments of eight photosensitive model compounds (PS) demonstrate that their triplet-excited states (³PS*) dominate sulfate formation for the photosensitizing pathway with a contribution of over 90%, and ¹O₂ plays an important role in sulfate formation. The results using humic acid (HA) and water-soluble organic carbon in vehicle exhaust particles (WSOC) as representatives of atmospheric photosensitizers further verify that triplet-excited DOM (³DOM*) is the main reactive species for sulfate formation, which is consistent with the results of PS. Our findings provide new insights into the photochemical formation pathways of atmospheric sulfate. Full article

This research shows the development of a miniaturized solid-phase extraction method with UV-Vis detection for simultaneous determination of dibenzofuran, fluoranthene and phenanthrene using chemometrics approaches. After synthesis of Fe₃O₄ nanoparticles (Fe₃O₄ NPs), the surface of the nanoparticles was modified by Triton X100 coating. The influence of extraction solvent and volume, concentration of Triton X100, extraction time, and sample pH were studied and optimized. Due to high spectral overlapping, resolving ternary mixtures for simultaneous determination of targets with classical analytical methods is impossible. Therefore, the recorded UV-Vis spectra were transformed using continuous wavelet transform and then subjected to artificial neural networks (ANNs). The Db4 mother wavelet was used as the better mother wavelet. For simultaneous detection of analytes, a comparison of feed-forward back-propagation and radial basis function networks was accomplished. The calibration graphs showed linearity in the ranges of 2.4–250 ng mL⁻¹, 50–3750 ng mL⁻¹, and 48–5000 ng mL⁻¹ with a limit of detection of 0.58, 9.5 ng mL⁻¹, and 12.5 ng mL⁻¹ under optimal conditions for phenanthrene, fluoranthene, and dibenzofuran, respectively. The limit of quantitation was achieved at 3.52 ng mL⁻¹, 16.35 ng mL⁻¹, and 31.3 ng mL⁻¹ for phenanthrene, fluoranthene and dibenzofuran, respectively. The method involving TX-100-coated Fe₃O₄ NPs in a liquid sample phase for analyte extraction, followed by ethanol desorption and UV-Vis detection, was successfully applied for the determination of polycyclic aromatic hydrocarbons in oil-field water and algae samples. Full article

Recent advancements in genome sequencing and bioinformatic analysis of fungal genomes have revealed that fungi possess cryptic or silent biosynthetic gene clusters (BGCs). This discovery suggests that our understanding of the universe of fungal secondary metabolomes is limited. In this review, we summarize recent strategies for activating cryptic BGCs in fungi, identify fungal secondary metabolites, and highlight their biological activities. We also briefly discuss the isolation and purification methods for these compounds. Our focus is on genetics-dependent and genetics-independent approaches for activating cryptic BGCs in fungi. Using the strategies discussed here, cryptic fungal natural products hold significant potential as a source for the discovery of new drug candidates. Full article

Apricot kernels are known to be rich in bioactive compounds such as polyphenols, which have applications in various fields such as cosmetology and the food industry. However, the extraction of these compounds has not been extensively studied. In this study, we aimed to extract oil from apricot kernels and investigate its composition and antioxidant properties. Samples from two years of apricot cannery by-products were used in the study. We employed a common extraction procedure using hexane as a solvent, followed by an analysis of the oil’s fatty acid composition and determination of its antioxidant properties using several methods. Our results indicated that the oil extracted from apricot kernels is rich in oleic and palmitoleic acids, which exhibit health benefits. As regards the volatile compounds of the oil, 2-methyl propanal, benzaldehyde, and benzyl alcohol were detected as the main compounds. Benzaldehyde was also found to be the main component of the essential oil of the kernel. Furthermore, the oil exhibited low antioxidant activity, as demonstrated by its ability to scavenge free radicals. Overall, our findings suggest that apricot kernels are a valuable source of oil with potential applications in the food and cosmetic industries. Full article

This work reports the effect of scaling up annular centrifugal contactors (ACCs) upon the residence time distribution and the efficiency of extraction of uranium. The experiments were carried out in a multi-scale ACC platform of three ACCs with rotor diameters of 12, 25, and 40 mm. To enable direct comparison across all three scales of ACC, the residence time distributions were acquired by injecting dye into the solvent phase at a constant relative volume related to the ACC liquid holdup. Across all scales and flowrates, there was little difference in residence time distribution (<6 residence volumes), except for the smallest 12 mm rotor diameter ACC with a high solvent/aqueous feed ratio, which required 12 residence volumes, potentially due to internal circulation in the annulus. At low flowrates, the stage efficiency in all cases was >95%, and it improved further in larger rotor diameter ACCs. Full article

Tepotinib (MSC2156119) is a potent mesenchymal–epithelial transition (MET) factor inhibitor, a receptor tyrosine kinase that plays a crucial role in promoting cancer cell malignant progression. Adverse effects of tepotinib (TEP), such as peripheral edema, interstitial lung disease, nausea and diarrhea, occur due to drug accumulation and lead to termination of therapy. Therefore, the in silico and experimental metabolic susceptibility of TEP was investigated. In the current work, an LC-MS/MS analytical method was developed for TEP estimation with metabolic stability assessment. TEP and lapatinib (LTP) used as internal standards (ISs) were separated on a reversed-phase C18 column using the isocratic mobile phase. Protein precipitation steps were used to extract TEP from the human liver microsome (HLM) matrix. An electrospray ionization multi-reaction monitoring (MRM) acquisition was conducted at m/z 493→112 for TEP, at m/z 581→350, and 581→365 for the IS. Calibration was in the range of 5 to 500 ng/mL (R² = 0.999). The limit of detection (LOD) was 0.4759 ng/mL, whereas the limit of quantification (LOQ) was 1.4421 ng/mL. The reproducibility of the developed analytical method (inter- and intra-day precision and accuracy) was within 4.39%. The metabolic stability of TEP in HLM was successfully assessed using the LC-MS/MS method. The metabolic stability assessment of TEP showed intermediate Cl_int (35.79 mL/min/kg) and a moderate in vitro t_1/2 (22.65 min), proposing the good bioavailability and moderate extraction ratio of TEP. The in silico results revealed that the N-methyl piperidine group is the main reason of TEP metabolic lability. The in silico Star Drop software program could be used in an effective protocol to confirm and propose the practical in vitro metabolic experiments to spare resources and time, especially during the first stages for designing new drugs. The established analytical method is considered the first LC-MS/MS method for TEP estimation in the HLM matrix with its application to metabolic stability assessment. Full article

Artemisia negrei (A. negrei) and Artemisia aragonensis (A. aragonensis) are in the family Asteraceae, which has been used in traditional medicine. The use of plant-derived insecticides has become a promising strategy to reduce the harmful effects of synthetic insecticides and overcome the bio-resistance of pest insects to insecticides. In this regard, the purpose of the current study was to determine the chemical composition and evaluate insecticidal effects of essential oils (EOs) extracted from A. negrei (EON) and A. aragonensis (EOA). Notably, all chemical constituents present in the EOs were identified through GC-MS analysis, whilst the insecticidal properties against Callosobruchus maculatus Fab. (C. maculatus) were investigated by use of in vitro an in silico approaches. The obtained results showed that both tested EOs present a significant insecticidal effect against C. maculatus, which increased significantly upon the dose used in both contact and inhalation tests. The lethal concentrations (LC₅₀) for the inhalation test were found to be 2.1 and 2.97 μL/L, while in the contact test they were 2.08 and 2.74 μL/L of air for EON and EOA, respectively. At 5 μL/L of air, the spawn reduction rate was 88.53 % and 77.41%, while the emergence reduction rate was 94.86% and 81.22% by EON and EOA, respectively. With increasing doses of up to 20 μL/L of air, the reduction in individual emergence reached 100% by the two oils tested after 36 h of treatment. In addition, Molecular docking (MD) simulations supported the in vitro findings and indicated that certain identified components in EOA and EON exhibited stronger hydrogen bonding interactions with the target receptors. Interestingly, the prediction of ADMET properties indicates that the molecules investigated have great pharmacokinetic profiles with no side effects. Taken together, our findings suggest that EOA and EON may exert both potential contact and inhalation insecticidal actions and could be used as an alternative tool for the control of this major insect pest of stored products. Full article

Lithium silicate (LS) crack repairing material, working as a crystal waterproof material, could be used to strengthen concrete made from solid waste materials. This paper presents the results of water absorption and rapid freeze–thaw tests with concrete specimens coated with LS. Concrete specimens with different water–binder ratios and air content (0.35–1 and 0.55–4.5) were tested. The moisture uptake and water absorption coefficient were analyzed in the water absorption test. The water absorption coefficient of LS-coated specimens was lower than that of uncoated specimens, resulting in a lower total moisture content. The relative dynamic modulus of elasticity was calculated by the fundamental transverse frequency (Er) and ultrasonic velocity (Ev), respectively. Er and Ev exhibited similar attenuation characteristics, and the attenuation of LS-coated specimens was lower than that of uncoated specimens. A two-segment freeze–thaw damage model based on Er and Ev was employed to predict the service life of concrete. The relative errors of the service life results calculated by Er and Ev were within 10%. The two-segment freeze–thaw model could be used for the service life prediction of concrete structures. The present work provides new insight into using LS to improve the service life of concrete. Full article

Molecularly imprinted polymers are prepared in the presence of a template. They have been shown to resolve enantiomers when used as stationary phases for liquid chromatography. However, the separation efficiency is not as good as that observed with silica stationary phases. This manuscript identifies the main problems as the slow transfer kinetics between the mobile and stationary phase and the heterogeneity of the stationary phase binding sites. It suggests that preparing templated polymers that have predominantly or exclusively noncovalent crosslinks is the most promising approach for improving efficiency. Full article

The Moroccan picholine tree’s leaves contain phenolic compounds that benefit human health. However, the amount and type of these compounds can vary based on factors such as the extraction method and conditions. This study aimed to improve phenolic compounds’ extraction while minimising harmful chemicals’ use. It has been found that using ethanol as a solvent with ultrasonic extraction is the most effective and environmentally friendly technique. Several parameters, such as the extraction time, solid/solvent ratio, and ethanol concentration as independent variables, were evaluated using a surface response method (RSM) based on the Box–Behnken design (BBD) to optimize the extraction conditions. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and also examined using the appropriate statistical methods. In optimal conditions, the ultrasonic time, the ratio (solvent/solid) and the concentration (ethanol/water), the content of total polyphenols (TPC), total flavonoids (TFC), and antioxidant activity (by DPPH, ABTS, FRAP) were, respectively, 74.45 ± 1.22 mg EAG/g DM, 17.08 ± 1.85 mg EC/g DM, 83.45 ± 0.89% 82.85 ± 1.52%, and 85.01 ± 2.35%. The identification of phenolic compounds by chromatography coupled with mass spectrum (HPLC-MS) under optimal conditions with two successive extractions showed the presence of hydroxytyrosol, catechin, caffeic acid, vanillin, naringin, oleuropein, quercetin, and kaempferol at high concentrations. Full article

This work presents a sustainable and rapid method for halogenated pesticide analysis without chromatographic separation. The system is composed of a microfluidic open interface (MOI) for solid-phase microextraction (SPME) liquid phase desorption, connected to a liquid electron ionization mass spectrometry interface (LEI-MS). Either a triple quadrupole mass spectrometer (QQQ-MS/MS, (low-resolution) or a quadrupole-time-of-flight tandem MS (QTOF-MS/MS, high-resolution) were employed, each operating in negative chemical ionization (NCI) conditions. The flow rate used (100 µL/min) to rapidly empty the MOI chamber (approximately 2.5 µL) is reduced to the working flow rate of the LEI interface (500 nL/min) by a passive flow splitter (PFS). NCI is an appropriate ionization technique for electrophilic compounds, increasing specificity and reducing background noise. Two halogenated pesticides, dicamba and tefluthrin, were extracted simultaneously from a commercial formulation matrix (CF) using a C18 fiber by direct immersion (3 min under vortex agitation). Analyte desorption occurred in static conditions inside MOI filled with acidified acetonitrile (ACN) (0.2% phosphoric acid, PA). Extraction and desorption steps were optimized to increase efficiency and accelerate the process. No chromatographic separation was involved; therefore, the system fully exploited MS/MS selectivity and HRMS accuracy demonstrating good linearity, repeatability and limits of detection (LODs) and limits of quantification (LOQs) in the pg/mL range (50 and 500 pg/mL, respectively). Low-resolution experiments showed that matrix effects (ME) did not affect the results. The fast workflow (5 min) makes the system suitable for high-throughput analysis observing the principles of green analytical chemistry (GAC). Full article

Hyperhidrosis is a condition characterized by excessive sweating that affects at least 5% of the world’s population. It is normally associated with unpleasant body odour which requires continuous maintenance throughout life. Antiperspirants and deodorants are the first-line treatments for hyperhidrosis. However, association of this class of product with the risk of other diseases has increased the search for an effective antiperspirant from natural sources. This study aimed to investigate the antibacterial and antiperspirant activities of Curcuma xanthorrhiza Roxb. Using an in vitro microbial assay against specific bacteria responsible for body odour and rat foot pad analysis. Quality control of the fractionated extract was conducted using reversed-phase HPLC based on two active markers: xanthorrhiza and curcumin. Toxicity tests were conducted based on the OECD guidelines (50–2000 mg/kg). Inhibition zone, MIC, and MBC values of the hexane fraction of C. xanthorrhiza showed equivalent antibacterial activity to positive control (p > 0.05). No swelling, redness, or rashes were observed at the injection area throughout the study. Treatment with 40, 80, and 160 mg/kg of the extract significantly decreased the sweat excretion up to 79.34% (p < 0.05) after 15 min compared to negative control. Histopathology analysis showed the reduced size of the secretory units in plantar sweat glands post treatment compared to negative control. In conclusion, the hexane fraction of C. xanthorrhiza is able to reduce sweat excretion in a rat model and inhibit the growth of bacteria causing body odour. Full article

Chinese prickly ash and cinnamon contain many antioxidants, which scavenge free radicals and can reduce many harmful compounds, such as heterocyclic aromatic amines (HAAs). Modern technologies used for cooking, such as the use of superheated steam roasting, are beneficial in decreasing the development of HAAs. The current study was based on the use of these two spices in roasted lamb patties to mitigate the formation of HAAs in superheated steam roasted patties. Results exhibited significant differences (p < 0.05) in the content of both polar and non-polar HAAs as compared to control patties. In cinnamon roasted patties, polar HAAs were reduced from 23.76 to 10.56 ng g⁻¹, and non-polar HAAs were reduced from 21.34 to 15.47 ng g⁻¹. In Chinese prickly ash patties, polar and non-polar HAAs were 43.60 ng g⁻¹ and 35.74 ng g⁻¹, respectively. Similarly, cinnamon-treated patties showed a significantly higher (p < 0.05) reduction in polar HAAs (23.52 to 12.41 ng g⁻¹) than non-polar (16.08 to 9.51 ng g⁻¹) at concentrations of 0.5–1.5%, respectively, as compared to the control, with 45.81 ng g⁻¹ polar and 35.09 ng g⁻¹ non-polar HAAs. The polar HAAs tested were PhIP, DMIP, IQx, and 8-MeIQx, while the non-polar were harman and norharman. Both spices and superheated steam controlled HAAs to a significant level in lamb meat patties. Full article