Methanol Concentration Research Articles

Production and Characterization of Red Fruit Spirits Made from Red Raspberries, Blueberries, and Strawberries.

This study demonstrated the feasibility of fermenting and distilling low-commercial-value red fruits such as red raspberries, blueberries, and strawberries to produce high-value red fruit spirits. The fermentation process was efficient, with all red berry wines achieving a notable ethanol conversion yield (46.33 to 66.31%), without the need for nutrient supplementation or fruit juice solid separation, which showed no significant effect on the quality of the final product. Small-scale copper Charentais alembic distillation of the fermented red fruit juices resulted in fruit spirits equivalent to 1%, 7%, and 2% of the initial volume for red raspberries, blueberries, and strawberries, respectively. Except for the blueberry spirit, which had a lower volatile compound concentration (79.4 g/hL, absolute alcohol), all the produced red fruit spirits complied with legislation, including ethanol (37.9-40.2% v/v) and methanol (22.8-877.9 g/hL, absolute alcohol) concentrations and exhibited favorable aromatic profiles. The findings highlight that fermentation and distillation are straightforward, consistent, and reproducible methods, enabling the production of high-quality red fruit spirits from economically viable red fruit sources. This presents a significant opportunity in the spirits market, offering versatile applications as low-alcohol options, base spirits, or, with re-distillation, high-alcohol spirits.

Determination of multiple residual solvents in ibandronate sodium using headspace-gas chromatography

Ibandronate sodium, a third-generation diphosphate drug used worldwide to treat osteoporosis, has the advantages of convenient use, low toxicity, and significant therapeutic effects. However, the residual organic solvents in the synthesis process of sodium ibandronate not only have a negative impact on the efficacy of the drug, but also lead to a decrease in drug stability. Moreover, if the residual amounts of these solvents exceed safety standards, they may pose serious threats to human health. This study successfully established a convenient and efficient method based on headspace-gas chromatography (HS-GC) for the simultaneous determination of five residual solvents (methanol, acetone, benzene, toluene, 1-pentanol) in the raw materials of ibandronate sodium. The results indicated that satisfactory analytical performance can be achieved by using DB-624 capillary column (30 m×0.32 mm×1.8 μm) and a flame ionization detector in conjunction with headspace autosampling and a temperature program. The specific operating conditions included an initial temperature of 40 ℃, with a hold of 2 min, followed by a temperature ramp first to 200 ℃ at a rate of 5 ℃/min and then to 240 ℃ at a rate of 20 ℃/min, with a hold of 5 min. Nitrogen with a flow rate of 1 mL/min and split ratio of 14∶1 was used as the carrier gas. The headspace vial temperature was maintained at 80 ℃, and the sample equilibration time was 20 min. Under the established analytical conditions, good linear relationships were obtained between the mass concentrations of methanol (72-216 μg/mL), acetone (120-360 μg/mL), benzene (0.048-0.144 μg/mL), toluene (21.36-64.08 μg/mL), and 1-pentanol (120-360 μg/mL) and their corresponding peak areas, with correlation coefficients (r) greater than 0.990. The limits of detection for these solvents were 2.88, 0.011, 0.90, 0.24, and 0.024 ng/mL, respectively, with limits of quantification of 11.5, 0.043, 3.6, 0.96, and 0.096 ng/mL, respectively. Furthermore, the recoveries of these solvents ranged from 86.3% to 101.9%, with relative standard deviations (RSDs, n=3) of less than 2.49%. The proposed method is simple, accurate, reliable, and suitable for the rapid and simultaneous determination of five residual solvents in the raw materials of ibandronate sodium. This study has important practical significance in improving drug safety and ensuring public health.

Ignition characteristics of ammonia-methanol blended fuel in a rapid compression machine

Ammonia has attracted wide attention in recent years as a carbon-free fuel. However, the low reactivity and combustion inertness of ammonia pose challenges to its applications in engines. Adding highly reactive fuels, such as renewable carbon–neutral methanol, offers a potential solution. To investigate the ignition characteristics of ammonia-methanol blended fuel, ignition delay time measurement and fast gas sampling under stoichiometric conditions with four ammonia blending ratios (20 % ammonia, A20; 40 % ammonia, A40; 80 % ammonia, A80; 95 % ammonia, A95) were carried out on a rapid compression machine under engine-relevant conditions. The effective thermodynamic conditions were 15–25 bar and 810–970 K. The concentrations of fuels NH3, CH3OH, and intermediate species N2O, CO, as well as products N2, CO2 were detected using gas chromatography. Chemical analysis was performed based on simulations using five ammonia-methanol reaction mechanisms. The ignition delay time results showed that the addition of methanol shortened the ignition delay time, with only a little change in ignition delay time beyond 20 % methanol content. Methanol significantly promoted the production of OH radical, leading to the enhancement of the overall mixture reactivity. The sampling results showed different consumption patterns of ammonia and methanol during the ignition process at different mixing ratios. For A80, methanol was consumed from the early stage of the ignition process, while ammonia consumption was negligible in the early stage. Conversely, for A95, ammonia consumption began in the early stage. This suggests that methanol and its intermediate species inhibited the consumption of ammonia, however, ammonia promoted the consumption of methanol. Chemical analysis further revealed that the inhibitory effect of methanol on ammonia consumption was weakened with the decrease of methanol proportion.

Effect of acetate and methanol on the kinetics of total dissolved selenium removal in a chemostat

AbstractBACKGROUNDCarbon (C) source consumption in industrial bioreactors removing soluble selenium (Se) contributes to the operating cost and can influence the rate of removal. This study used a laboratory chemostat to investigate the dependency of the rate of dissolved Se removal on the concentration of acetate and methanol, two C sources used in treatment of Se containing mine‐influenced water. It was hypothesized that the rate of dissolved Se removal follows a Monod kinetic model with C source as the limiting substrate.RESULTSA chemostat fed with 25 mg‐selenate‐Se L−1 and acetate as C source at different concentrations operated over a range of hydraulic retention times (HRTs) achieved maximal removal of 99.7% dissolved Se at an HRT of 1.5 days [rate 16.7 mg‐Se (L day)−1]. When methanol was fed into the chemostat as the C source instead of acetate, the extent and rate of removal were much less [65% at an HRT of 6 days, rate 2.7 mg‐Se (L day)−1]. Carbon source consumption per mole of dissolved Se removed was not constant and exceeded stoichiometric estimates. Monod kinetic parameters for the Dechloromonas/Ralstonia consortium growing on acetate were estimated as = 3.36 mg‐C L−1 and = 0.70 L day−1. The Methylophilaceae consortium growing on methanol did not exhibit Monod kinetic growth.CONCLUSIONSUsing acetate as a C source achieved greater efficiency of dissolved Se removal than when methanol was used. Total dissolved Se removal rate was dependent on acetate only at low concentrations and when the HRT was close to washout. However, total dissolved Se removal rate was strongly dependent on HRT when methanol was used. © 2024 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

Study on the liquid–liquid phase separation phenomenon of iohexol in a binary mixed solvent of methanol and n-butanol: Thermodynamic behavior and molecular dynamics calculation

The impact of oiling-out on the control of the crystallization purification process during iohexol crystallization is significant. Thus, the solubility of iohexol and its oiling-out behavior in a binary solvent mixture of methanol and n-butanol was investigated in this study. The solubility was determined using the equilibrium method at temperatures ranging from 273.15 K to 303.15 K under atmospheric pressure, revealing that solubility increases with temperature and methanol concentration. Four models were employed to model the solubility data, with the CNIBS/R-K model demonstrating the highest correlation. The van't Hoff equation was utilized to calculate the thermodynamic properties, the result indicating that enthalpy predominates in the dissolution process. Furthermore, ternary phase diagrams were constructed to elucidate the nucleation mechanism of iohexol, identifying nucleation sites and performing kinetic simulations from a molecular perspective. These analyses indicated that lower temperatures are favor the control of oiling-out phenomena. The nucleation of iohexol is characterized by a two-step mechanism, initiating with liquid–liquid separation, followed by nucleation and crystal growth. Solubility parameters, derived using Materials Studio, suggest enhanced interactions between iohexol and methanol, which is also corroborated by the solvation energy data from Gaussian software. This interaction explains the tendency of iohexol to oiling out in mixed solvents. Radial distribution function (RDF) analysis illustrates that methanol-iohexol interactions intensify prior to oiling-out, reach a peak during oiling-out, and diminish after nucleation due to desolvation. The occurrence of oiling-out can lead to challenges such as diminished product quality, reduced yields, and difficulties in reprocessing. Therefore, understanding the mechanism of oiling-out is fundamental to addressing these issues, rendering these insights invaluable for the study of crystallization processes and oiling out phenomena in other small organic molecules.

Electron-catalytic conversion of carbon dioxide into formaldehyde and methanol

Since the mid-19th century, there has been a steady increase in the amount of CO2 in the atmosphere, leading to global warming due to the greenhouse effect. CO2 can be utilized to obtain a large number of organic compounds. The formation of these compounds depends on the methods of CO2 processing, which include biological, thermal conversion, photochemical, and plasma methods. Most of these methods involve the use of catalysts. One of the plasma methods is the electron-catalytic method using a barrier discharge. Studies on the catalytic conversion of CO2 into methanol and formaldehyde were carried out on a laboratory setup consisting of two sources of low-temperature plasma – dischargers, one of which contains a heterogeneous catalyst. Water vapor was used as the source of hydrogen. The formation of methanol and formaldehyde was investigated under different operating modes of the setup. The effect of sample aging for a day was determined. As a result, there is an increase in the concentration of methanol in the sample from 5.8% to 49.74% and formaldehyde from 4.1% to 50.01% for different operating modes of the setup. The observed results are explained by a sharp increase in the yield of oxygen-containing radicals and , which are formed by the interaction of ozone, formed from CO2 in the discharge zone, with aqueous solutions.

Direct methanol oxygen-ion conducting solid oxide fuel cell with an integrated in-situ cracking reactor

Methanol, as an indirect hydrogen storage medium rich in hydrogen, is considered an ideal fuel for fuel cells. Oxygen-ion conducting solid oxide fuel cells (O-SOFCs) powered by methanol are renowned for their high energy conversion efficiency and minimal environmental impact, offering broad application prospects. However, challenges to their stable power generation arise from the rate of hydrogen production through methanol decomposition at the anode and carbon deposition on nickel-based anodes. To address these issues, this study explores the optimal operating temperature and concentration of methanol as an O-SOFCs fuel, while also developing a novel cell design. In this design, an in-situ cracking reactor for internal conversion of methanol is constructed by loading Ru-GDC high-efficiency nanofiber catalysts on dendritic anode microchannels, significantly enhancing the cell's power generation performance. Experimental results demonstrate that at 800 °C and a 30 % methanol concentration, the system increases the maximum power density (MPD) from 0.622 W cm−2 to 0.893 W cm−2, exhibiting a 43.57 % increase in power density and a 13.03 % improvement in methanol utilization. Additionally, the system effectively mitigates carbon deposition and nickel anode deactivation, thereby enhancing the cell's operational stability.

Simultaneous determination of seawater trimethylamine and methanol by purge and trap gas chromatography using dual nitrogen-phosphorus detector and flame-ionization detector

Compounds containing one carbon atom or no carbon-carbon bond (C1 compounds), such as trimethylamine and methanol, are important climate relevant gases in the atmosphere and play key roles in global warming. The ocean is a significant source or sink of such compounds, while the concentrations of trimethylamine and methanol in seawater remain largely unconstrained due to the analytical challenges involved. Therefore, it is necessary to establish a continuous, rapid and sensitive method for the determination of these compounds with high polarity, volatility or solubility at low seawater concentrations. Here we developed a purge and trap system, coupled to a gas chromatography equipped with dual nitrogen phosphorus detector (NPD) and flame ionization detector (FID) for the simultaneous online analysis of trimethylamine and methanol at nanomolar range using a small sample volume (~ 10 mL). The dual detection of trimethylamine and methanol with NPD or FID was achieved by installing a capillary flow splitter between the capillary column and detectors. After modification and optimization of the setup and conditions, excellent linearity (R2 > 0.99) and repeatability (< 6%) were obtained for both compounds; the detection limits for trimethylamine and methanol were 0.3 nM and 17.6 nM, respectively. Using this method, water samples collected from coastal and open ocean were analyzed; trimethylamine and methanol concentrations ranged from 0.6 to 18.8 nM and 26.0 to 256.2 nM, respectively. Collectively, this method allowed for online, rapid, sensitive and simultaneous quantification of trace trimethylamine and methanol concentrations with low-cost instrumentation and small sample volume, which makes it promising for further application in volatile compounds analysis in marine environments.

Production of NiCoMo-Supported Ni Foam for Electrocatalytic Oxidation of Methanol: Experimental and RSM Analysis

The Ni-, Co-, and Mo-supported Ni foam (NiF–NiCoMo) was produced via galvanostatic method, and electrooxidation of methanol in alkaline medium was examined. The characterization was achieved using field emission scanning electron microscopy, energy-dispersive X-ray, and X-ray diffraction analysis. The electrochemical behavior was determined via cyclic voltammetry and chronoamperometry analysis. The contribution of each transition metal to electrocatalytic performance of NiF was monitored via mono, binary, and ternary modifications of each transition metal (Ni, Co, and Mo) for several amounts (5, 10, and 15 μg). Experiments were performed to determine the influence of catalyst amounts, methanol concentration, and scan rate parameters. The impacts of independent parameters on methanol electrooxidation were statistically investigated using Design-Expert software. The ability to analyze multiple parameters with a limited number of experimental performances is one of the method’s key benefits. The developed model showed that 9.41 and 14.03 µg catalyst amounts were the appropriate values for NiF–NiMo and NiF–NiCoMo achieving optimal circumstances, respectively.

Enhancing methanol tolerance of Thermomyces lanuginosus lipase by rational design and biodiesel production through one-step feeding of methanol

The addition of a significant quantity of methanol solution during the biodiesel production results in the denaturation of lipase. To address this issue, this study proposed a novel approach to the preparation process by designing a methanol-tolerant Thermomyces lanuginosus lipase (TLL) using a computer-aided strategy. In silico prediction yielded seven mutants, out of which two mutants, E129Y and E134W, exhibited varying degrees of improved methanol tolerance and catalytic efficiency. The methanol tolerance and stability of E129Y and E134W were observed to increase by 10–30 % and 17–35 %, respectively. Additionally, E134W exhibited a 1.13-fold increase in catalytic efficiency compared to the wild type TLL, while E129Y showed a reduction of 12.05 %. Following a one-shot addition of methanol (molar ratio of 3:1 methanol to Cornus wilsoniana oil) for 72 h in the transesterification reaction, the yields of fatty acid methyl ester (FAME) for E129Y and E134W were 69 % and 85 %, respectively, with the yield of E134W increasing by 22 %. Structural analysis indicated that the E129Y mutation formed a single hydrogen bonding interaction, while E134W produced hydrophobic interactions with neighboring amino acids, thereby augmenting the structural stability of the mutations under high methanol concentration. This study has the potential to advance the commercialization of lipases in the biodiesel production industry.

Porous Anisometric PNIPAM Microgels: Tailored Porous Structure and Thermal Response.

The porous structure of microgels significantly influences their properties and, thus, their suitability for various applications, in particular as building blocks for tissue scaffolds. Porosity is one of the crucial features for microgel-cell interactions and significantly increases the cells' accumulation and proliferation. Consequently, tailoring the porosity of microgels in an effortless way is important but still challenging, especially for nonspherical microgels. This work presents a straightforward procedure to fabricate complex-shaped poly(N-isopropyl acrylamide) (PNIPAM) microgels with tuned porous structures using the so-called cononsolvency effect during microgel polymerization. Therefore, the classical solvent in the reaction solution is exchanged from water to water-methanol mixtures in a stop-flow lithography process. For cylindrical microgels with a higher methanol content during fabrication, a greater degree of collapsing is observed, and their aspect ratio increases. Furthermore, the collapsing and swelling velocities change with the methanol content, indicating a modified porous structure, which is confirmed by electron microscopy micrographs. Furthermore, swelling patterns of the microgel variants occur during cooling, revealing their thermal response as a highly heterogeneous process. These results show a novel procedure to fabricate PNIPAM microgels of any elongated 2D shape with tailored porous structure and thermoresponsiveness by introducing the cononsolvency effect during stop-flow lithographypolymerization.

Multi-Omics Analysis of the Co-Regulation of Wood Alcohol Accumulation in Baijiu Fermentation

Methanol, also known as wood alcohol, is a common hazardous by-product of alcoholic beverage fermentation and serves as a crucial indicator for assessing the safety of alcoholic beverages. However, the metabolic mechanisms of methanol production during the solid-state fermentation of Chinese Baijiu remain unclear. In this study, we sought to determine the primary stage of methanol production in Chinese Baijiu by measuring the methanol content at different stages of fermentation. High-throughput multi-omics sequencing techniques were employed to elucidate methanol metabolic pathways and associated microorganisms. In addition, a comprehensive analysis incorporating environmental factors and microbial interactions was conducted to explore their combined effects on methanol production. Methanol was predominantly produced during pit fermentation, with the most significant increase observed within the first seven days. Microorganisms such as Pichia kudriavzevii, Byssochlamys spectabilis, Penicillium, and Aspergillus played a regulatory role in methanol content during the first seven days through their involvement in butyrate and methane metabolic pathways and pectin degradation modules. During Baijiu production, various types of molds and yeasts participate in methanol production. Differences in their abundance within fermentation cycles may contribute to variations in methanol content between stages. Lactobacillus accumulated abundantly in the first seven days in each stage, suppressing methanol-metabolizing microorganisms. In addition, the increased acidity resulting from Lactobacillus metabolism may indirectly promote methanol generation.

Unsupervised Clustering-Assisted Method for Consensual Quantitative Analysis of Methanol-Gasoline Blends by Raman Spectroscopy.

Methanol-gasoline blends have emerged as a promising and environmentally friendly bio-fuel option, garnering widespread attention and promotion globally. The methanol content within these blends significantly influences their quality and combustion performance. This study explores the qualitative and qualitative analysis of methanol-gasoline blends using Raman spectroscopy coupled with machine learning methods. Experimentally, methanol-gasoline blends with varying methanol concentrations were artificially configured, commencing with initial market samples. For qualitative analysis, the partial least squares discriminant analysis (PLS-DA) model was employed to classify the categories of blends, demonstrating high prediction performance with an accuracy of nearly 100% classification. For the quantitative analysis, a consensus model was proposed to accurately predict the methanol content. It integrates member models developed on clustered variables, using the unsupervised clustering method of the self-organizing mapping neural network (SOM) to accomplish the regression prediction. The performance of this consensus model was systemically compared to that of the PLS model and uninformative variable elimination (UVE)-PLS model. Results revealed that the unsupervised consensus model outperformed other models in predicting the methanol content across various types of methanol gasoline blends. The correlation coefficients for prediction sets consistently exceeded 0.98. Consequently, Raman spectroscopy emerges as a suitable choice for both qualitative and quantitative analysis of methanol-gasoline blend quality. This study anticipates an increasing role for Raman spectroscopy in analysis of fuel composition.

Purification, characterization of a plant esterase from red kidney bean and its feasibility for pesticide residue analysis in foods

Plant-derived esterase is a promising alternative enzyme source for pesticide residue analysis. The present study aimed to obtain purified red kidney bean esterase (RKBE), investigate its biochemical properties and application potential in pesticide residue assay. RKBE was extracted and purified by simple aqueous two-phase extraction combined with dextran gel filtration chromatography, with specific activity of 11.845 U/mg and purification fold of 18.952. SDS-PAGE revealed that RKBE has a molecular weight of 33 kDa. Preliminary structural characterization showed the amino acid sequence of RKBE was similar to that of α/β-hydrolase (ESW18998) derived from Phaseolus vulgaris with 19.5% sequence coverage, and the relative contents of β-sheet, β-turn, α-helix, and random coil were 22.69%, 24.19%, 30.12%, and 23.00%, respectively. The optimal pH and temperature of RKBE were 6.5 and 40 °C. Ca2+, Mg2+, Zn2+, and low concentrations of methanol and ethanol stimulated the enzyme activity. The half-life was 138.6 days at −20 °C. Kinetic studies showed that RKBE exhibited a high affinity and catalytic activity towards 1-naphthyl acetate, with a Km of 0.277 mM and a Kcat/Km of 0.455 s−1 mM−1. Enzyme-specific inhibition assay indicated RKBE to be a carboxylesterase. Finally, pesticide susceptibility experiments confirmed that organophosphorus and carbamate pesticides exerted inhibitory effects on RKBE catalytic activity. For methamidophos, methomyl, dichlorvos, and carbaryl, the limit of detection (IC10) values in cabbage were 0.0031, 0.0045, 0.001, and 0.0065 mg/kg, respectively, suggesting that RKBE can serve as a new, widely available and cost-effective enzyme source for pesticide residual assay in foods.

Mathematical Modelling and Simulations of Active Direct Methanol Fuel Cell

A one dimensional isothermal model is proposed by modelling the kinetics of methanol transport at anode flow channel (AFC), membrane and cathode catalyst layer of direct methanol fuel cell (DMFC). Analytical model is proposed to predict methanol cross-over rate through the electrolyte membrane and cell performance. The model presented in this paper considered methanol diffusion and electrochemical oxidation at the anode and cathode channels. The analytical solution of the proposed model was simulated in a MATLAB environment to obtain the polarization curve and leakage current. The effect of methanol concentration on cell voltage and leakage current is studied. The methanol cross-over has the significant impact on cell performance. The presented model predicts higher leakage current with the increase of methanol feed concentration. The cell performance was predicted at 70°C and various methanol feed concentration. The proposed model was validated with the experimental polarization curve of active DMFC.

The Experimental Investigation of the Effects on the Combustion, Performance, and Emission Characteristics of an RCCI Engine Using Methanol/Diesel Fuel

Reactivity-controlled compression ignition (RCCI) combustion is considered one of the most promising low-temperature combustion (LTC) concepts aimed at reducing greenhouse gases for the transportation and power generation sectors. RCCI combustion mode is achieved by combining different fuel types with low and high temperatures. The aim of this study is to investigate combustion characteristics and reduce nitrogen oxide (NOx) and carbon dioxide (CO2) emissions. In this experimental study, the effects of the RCCI strategy using methanol/diesel fuel on combustion characteristics (ignition delay, combustion duration), engine performance (brake-specific fuel consumption and brake-specific energy consumption), and emissions were examined in a four-cylinder, turbocharged, dual-fuel engine. The experiments were conducted at a constant speed of 1750 rpm at partial loads (40 Nm, 60 Nm, 80 Nm, and 100 Nm). The test results obtained with diesel fuel were compared with the test results obtained with methanol at different mass flow rates. When the results were examined, the minimum ignition delay (ID) occurred at 40 Nm torque, 5.63 crank angle (CA) with M12 fuel, while the maximum ID occurred with M26 fuel at 80 Nm torque, showing an increasing trend as engine load (EL) increased. The highest combustion time (CD) was achieved with M26 fuel at 100 Nm torque, whereas the lowest was achieved with the same fuel (M26) at 40 Nm. While the minimum brake-specific fuel consumption (bsfc) was 45.9 g/kWh for conventional diesel fuel at 40 Nm, the highest bsfc was 104.88 g/kWh for 100 Nm with M26 fuel. Generally, bsfc tends to increase with increasing load. Brake-specific energy consumption (bsec) had the lowest value of 1950.58 kJ/kWh with conventional diesel fuel at 40 Nm and the highest value of 4034.69 kJ/kWh with M26 fuel at 100 Nm. As the methanol content increased, significant improvements were observed in (NOx) and (CO2) emissions, while hydrocarbon (HC) and oxygen (O2) emissions increased as well. Smoke emissions decreased at low loads but tended to increase at high loads.

Evaluation of total flavonoids, total phenolic content and biological activity of Iraqi Lipedium sativum L. crude extract obtained by optimized ultrasound assisted extraction conditions

Lepidium sativum L. also known as garden cress belong to the family Brassicaceae. The plant species composed of various phytochemicals as well as powerful nutraceutical potential and possess several bioactivities like, hepatoprotective, antioxidant, anticancer, antimicrobial, hypoglycemic, gastrointestinal and bone healing activities. This research paper presents an investigation into the total flavonoids (TFC), total phenolic content (TPC) and biological activity of Iraqi Lepidium sativum L. The study aimed to optimize ultrasound-assisted extraction conditions to obtain a crude extract with enhanced bioactive components. Three variables were examined including methanol concentration, extraction time and ultrasound frequency. The optimum yields of extract, TFC and TPC were (3.22 ± 0.049 g/10 g of dry plant), (17.03 ± 0.060 mg RE/g) and (10.96±0.020 mg GAE/g) respectively. The optimal extraction conditions contributed to these values of experiment 2 and 3 were 70% methanol, 10 min and 40 KHz and 70% methanol, 15 min and 40 KHz respectively. The lowest IC50 values of optimized methanolic extracts of Iraqi Lepidium sativum aerial parts against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals were 31.84 µg/mL for TFC and 35.85 µg/mL for TPC . For the first time, the study provided data about the phenolic and flavonoid contents of the Iraqi plant and optimized conditions for extraction by UAE technique using single factor experiment. The plant can be acknowledged as a potential nutraceutical or functional food rich in antioxidants to combat many diseases.

An on-chip microarray platform for material-temperature optimization and gas discrimination

The demand for gases detection has promoted extensive research into gas sensors. Sensor arrays can be used as electronic olfaction units for complex gas detection and identification. However, the gas sensing properties are affected by various factors. The multi-dimensional nature of those interactions is crucial for creating a sensor array with diverse responses, but it is also challenging to fabricate an array considering all these parameters, particularly in miniaturization. In this paper, we present a framework that can take multiple factors into consideration and help to fabricate an optimal array for gas identification. 32 sensors including different MOS materials (SnO2, In2O3, WO3), morphologies (microsphere, nanoparticle, nanoflake), doped/loaded metals (Pd, Pt, Ce, Ru, Rb), and operational temperatures (250℃∼370℃) are discussed. A material-temperature-analyte-response database was then established by storing their response characteristics towards low ppm concentrations of ammonia, ethyl acetate, toluene, methanol, ethanol, and acetone. An optimized array was then constructed out of 10,518,300 possible combinations of materials and operational temperatures. Results showed improvements in discrimination ability and the optimized array integrated into the chip can provide vector signals with high selectivity, completely recognizing all the 6 target gases and even for their multi-component mixture after linear discriminant analysis transformation.

Methanol intoxication in the central region of Saudi Arabia: Five case studies

Outbreaks of methanol poisoning have been described in the medical literature worldwide. However, the few outbreaks that have occurred in Saudi Arabia remain undocumented. This is especially noteworthy in light of the fact that Saudi Arabia is among the countries that explicitly prohibit the usage of alcoholic beverages and recreational drugs. Herein, we describe five cases of methanol poisoning in Saudi Arabia. The first three comprise patients admitted to the emergency room (ER) with signs of methanol toxicity, such as heart palpitations, vomiting, and blurred vision; otherwise, those patients were considered medically free. The remaining two cases were examined postmortem. A headspace gas chromatography-flame ionization detector was used to test blood, vitreous humor, and urine samples for methanol. Specific lethal concentrations of methanol were defined based on published case studies as 23–740 mg/dL in blood and 12–396 mg/dL in vitreous humor. In postmortem cases of our present study, samples exhibited lethal concentrations: 118 and 257 mg/dL in blood, 116.3 and 283 mg/dL in vitreous humor. In ER cases, methanol concentrations in urine samples were lower, at 7.5, 9.1, and 20.9 mg/dL; however, toxic symptoms were still observed. These case studies indicate that it is necessary to raise community awareness about the risk of methanol poisoning in order to minimize future poisoning epidemics.

Optimization of methyl ester synthesis using gas/liquid phase pulsed discharge plasma in a novel oscillatory slug flow reactor

In the present research, an innovative oscillatory slug flow reactor (OSFR) under the treatment of gas–liquid phase pulsed discharge plasma was developed for biodiesel production. The main goal was continuous production of high quality biodiesel at low temperature and pressure. Experimental tests were carried out under the influence of four main operating parameters including applied voltage, molar ratio, reactant flow rate, and catalyst concentration. The response surface method was employed to optimize experimental tests. The results showed that the proposed technology provided 94% production efficiency under the optimal conditions of voltage 19.4 kV, molar ratio 6.4, flow rate 2.7 ml/s, and catalyst 0.9 wt. %. According to the statistical analysis, increasing the applied voltage and reducing the flow rate have a strong effect on the Fatty Acid Methyl Ester yield, while the concentration of potassium hydroxide and methanol have less effect on the overall efficiency. In addition, the characteristics of the produced biodiesel were in accordance with ASTM D6751 standards. Surprisingly, the optimal energy consumption in this system was 95 kJ/l, which is more economically viable. In general, this study showed that the combined system of gas/liquid phase plasma in the OSFR reactor has a high synergistic potential for the transesterification reaction.