Gas Chromatography-mass Spectrometry Method Research Articles

Network pharmacology-based approach to investigate the molecular targets of essential oil obtained from lavender for treating breast cancer

Lavender essential oil (LEO) is known for its medicinal use in the development of pharmaceuticals. Further investigations were demonstrated that LEO has many biological properties including apoptosis. However, The anti-breast cancer activity and mechanism of LEO are still unclear. we aim to elucidate the elusive anti-breast cancer activity and mechanism of LEO by unveiling the intricate molecular targets that it engages with, thereby priming it for effective therapeutic intervention against breast carcinoma. In this paper, we extracted LEO from lavender and analyzed it's chemical constituents by using hydro-distillation and gas chromatography-mass spectrometry (GS-MS/MS) method, respectively. The active components against breast cancer and it's molecular targets were selected and biological process, molecular function, cellular component and involving pathways were evaluated via network pharmacology approach. Cell viability, apoptosis and cell cycle assay were used to evaluate anti-breast cancer effect of LEO. Employing the western blotting method to validate target protein expression following LEO treatment in vitro. We found the 21 effective components and 213 drug-disease common targets of LEO. Amoung them, 7 active components and 19 targets were identified as potential therapeutic targets. Gene ontology results revealed that the drug-disease common targets of LEO were mainly distributed in membrane region, involved in peptide-tyrosine phosphorylation, and primarily associated with protein tyrosine kinase. We also found that drug-disease common targets might contribute to the regulation of PI3K-AKT signaling pathway by using KEGG pathway analysis. Besides, our study demonstrated reduced cell viability, induced apoptosis in MCF-7 and MDA-MB-231 treated with LEO while cell cycle arrest was not altered. The AKT1 expression down-regulated while PIK3CA expression was increased in both cell lines. Our findings indicate that LEO has the ability to induce apoptosis by modulating the expression of PI3K-AKT signaling pathway in these cell lines.

Volatile Profile in Greek Grape Marc Spirits with HS-SPME-GC-MS and Chemometrics: Evaluation of Terroir Impact.

Greek grape marc spirits, although being traditional products, have lately attracted increasing attention as a revisited spirit product category. A headspace solid-phase microextraction coupled to the gas chromatography-mass spectrometry method was optimized in order to determine the volatile composition of 39 samples of grape marc spirits from eight major geographical regions of Greece and 4 protected designations of origin (PDOs). This untargeted analysis approach yielded the identification and quantification of 200 volatiles characterizing those products. Principal component analysis and partial least-squares-discriminant analysis (PLS-DA) combined with the volatile matrix were further employed to identify terroir denomination. Initial results showed a clear separation of the PDO products from Tyrnavos from the rest. Variable importance in projection data pretreatment was further adopted, and with 31 volatiles subsequently used with PLS-DA, products were correctly classified according to region of origin at 76.92% and for 3 out of 4 PDO denominations at 100%.

Chemical profile and biological properties of the essential oil of Rosemary leaves (Rosmarinus officinalis L.)

Rosemary leaf essential oil (RoEO) is extracted using steam distillation. The aim of study is to determine physicochemical characteristics of essential oil (EO), such as acid/saponification/esterification index, relative/absolute density, freezing point, and fragrance retention. The chemical composition of EOs was analyzed by gas chromatography-mass spectrometry (GC-MS) method and identified 50 volatile compounds, of which α-Pinene (33.76%), 1,8-Cineole (18.47%), and Levoverbenone (6.11%) constituted the highest proportions in EO. The antioxidant capacity (AC) of the EO was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method with a half-maximum inhibitory concentration (IC50) of 425.473 mg/mL. In particular, antibacterial activity (AA) by the paper plate diffusion method for susceptibility testing to essential oil showed that RoEO strongly inhibited the growth of four tested bacterial strains (Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium, and Escherichia coli). Perhaps, it is possible to apply RoEO in the food industry and other fields owing to the good properties of RoEO.

Determination of the constituents, inhibition microorganisms tested and microorganisms in pork of the essential oil from Eucalyptus citriodora Hook leaves

The objective of this study is to determine all the constituents, inhibition microorganisms tested and microorganisms in pork of the essential oil from Eucalyptus citriodora Hook leaves. The essential oil from Eucalyptus citriodora Hook leaves in Vinh Phuc, was obtained by steam distillation and dried with Na2SO4. By Gas chromatography-mass spectrometry (GC-MS) method, seventeen components in the essential oil of Eucalyptus citriodora Hook leaves were predicted by comparing their retention times and molecular weights with the standards. In particular, among thirteen hydrocarbons, monoterpene accounts for 1.74%, and sesquiterpene accounts for 22.30%; Among the 14 oxidized hydrocarbon components: 24.72% alcohols, 5.95% ketones, 29.84% aldehydes, and 14.26% esters. The results showed that the essential oil of Eucalyptus citriodora Hook leaves possessed antibacterial activity against all of the five microorganisms tested. Among them, the antibacterial activity against Bacillus subtilis, Salmonella enterica, and Lactobacillus fermentum was the highest. Therefore, based on the microbiological criteria and to reduce the cost during the preservation process, the content of essential oil of Eucalyptus citriodora Hook leaves of 0.4% per pork weight was selected as the basis for building a process to preserve pork with essential oil of Eucalyptus citriodora Hook leaves at 6oC. This is the scientific basis for the application of essential oil Eucalyptus citriodora Hook leaves in food processing and preservation, which is very necessary with high scientific and practical significance.

Development and Validation of a Gas Chromatography-Mass Spectrometry Method for the Analysis of the Novel Plant-Based Substance with Antimicrobial Activity.

The research into new pharmaceutical substances based on essential oils, individual biologically active phytochemicals, and plant extracts is a priority in field of pharmaceutical sciences. A novel multicomponent substance based on Melaleuca alternifolia (M. alternifolia) leaf oil (TTO), 1,8-cineole (eucalyptol), and (-)-α-bisabolol with potent synergetic antimicrobial activity was investigated and suggested for the treatment of seborrheic dermatitis (SD) and dandruff. The objective of this research was to establish and validate a specific, accurate, and precise gas chromatography-mass spectrometry (GC-MS) method for further quantitative and qualitative analysis in order to ensure quality control. The main parameters of validation were suitability, specificity, linearity, accuracy, and intermediate precision according to the European Pharmacopoeia (XI edition), Russian Pharmacopoeia (XIV edition), and some parameters of ICH requirements. The peaks of fifteen chemical phytoconstituents were identified in the test sample solution with the prevalence of (-)-α-bisabolol (27.67%), 1,8-cineole (25.63%), and terpinen-4-ol (16.98%). These phytochemicals in the novel substance were chosen for standardization and validation of the GC-MS method. The chosen chromatographic conditions were confirmed for testing of the plant-based substance in a suitability test. It was established that the GC-MS method provides a significant separation, symmetry of peaks and resolution between phytochemicals. The calibration curves of each phytochemical had good linearity (R2 > 0.999) in five concentrations. In the same concertation range, the accuracy of terpinen-4-ol, 1,8-cineol, and (-)-α-bisabolol determination using the method of additives was 98.3-101.60%; the relative standard deviation (RSD) ranged from 0.89% to 1.51% and corresponded to requirements. The intraday and interday precision was ≤2.56%. Thus, the GC-MS method was validated to be specific, sensitive, linear, accurate, and precise. This GC-MS method could be recommended as a routine analytic technique for multicomponent plant-based substances-enriched terpenes.

Determination of 14 volatile organic compounds in urine by headspace gas chromatography-mass spectrometry

Objective: To establish a automatic headspace gas chromatography-mass spectrometry (HS/GC-MS) method for the determination of 14 volatile organic compounds in urine. Methods: In September 2022, 10 ml urine sample was taken into a 20 ml headspace bottle, balanced for 30 min at 65 ℃, and then detected by HS/GC-MS and quantified by external standard method. Results: The 14 volatile organic compounds showed good linearity at 0.2-8.0 μg/L and 0.1-4.0 μg/L, with correlation coefficients ranging from 0.9956-0.9999. The recoveries were 79.8%-113.1% with relative standard deviations 0.05%-0.27% when three different concentration levels were added. Detection limit was 0.03-0.05 μg/L. Conclusion: The method is simple and convenient, and the recovery and precision meet the requirements. It can be used for the determination of common volatile organic compounds in urine.

Covalent organic framework modified nickel foam adsorbents for dispersive micro-solid phase extraction of polycyclic aromatic hydrocarbons from Chinese herbal medicines

Sixteen polycyclic aromatic hydrocarbons (PAHs) contaminants in Chinese herbal medicines were determined based on metal covalent organic framework (MCOF) combined with gas chromatography-mass spectrometry (GC–MS) and dispersive micro-solid phase extraction (D-μ-SPE) methods. The MCOFs were constructed by using 2,5-dihydroxy-1,4-benzenedicarboxaldehyde (Dt) and 4′,5′-bis(4-aminophenyl)-[1,1′′,2′,1′′-triphenyl]-4,4′′-diamine (BAPTPDA) as monomers. The morphological structures were characterized by scanning electron microscopy and the stability of BAPTPDA-Dt was characterized by various techniques such as fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The results showed that nickel foam (NF) was covered by covalent organic frameworks and that NF@COF (BAPTPDA-Dt) exhibited excellent stability. The adsorption capacity of MCOF for PAHs ranged from 30.8 to 262.5 mg g−1. A number of parameters that might affect the extraction efficiency of D-μ-SPE were optimized, which resulted in a more efficient and time-saving extraction process (2 min) with less consumption of organic reagents (1 mL). The qualitative and quantitative analysis of the 16 PAHs was performed by GC–MS with the limits of detection ranging from 0.55 to 5.93 µg/L. A wide linear range (20–2000 µg/L) was achieved with coefficient of determination (R2) between 0.9930 and 0.9994. The recoveries for the three spiked sample concentrations (20, 200 and 500 µg/L) varied from 80.8 % to 126.7 %. The relative standard deviations (RSDs) for PAHs were all less than 7.79 %. The total contents of the 16 PAHs contained in the five herbs (Gardenia, Plantain Seed, Rhizoma Alismatis, Evodia Fruit and Peucedani Radix) were in the range of 308–1070 µg kg−1. The results indicated that the established method has significant repeatability and reproducibility.

CHEMICAL CONSTITUENTS OF SPHALLEROCARPUS GRACILIS (BESSER EX TREVIR.) ESSENTIAL OILS FROM BURYATIAN FLORA

Relevance. Sphallerocarpus gracilis (Besser ex Trevir.) Koso-Pol. (Umbelliferae) is a biennial pubescent plant widely used in the practice of Oriental medicine. Research on S. gracilis is attracting increasing attentiom due to its potential biological zctivities: antioxidant, hepatoprotective effects, anticancer properties, essential oils exhibit significant antimicrobial properties. Material and methods. Essential oils of the aerial part and roots of the Sphallerocarpus gracilis from Mukhorshibirsky district of the Republic of Buryatia, collected during the period of mass flowering (August, 2022), were studied. Essential oils from the herbs and roots were isolated by hydrodistillation method. The content of essential oils was found by volumetric method. The qualitative composition and quantitative content of essential oils components were determined by gas chromatography-mass spectrometry method. Results. The qualitative composition and quantitative content of essential oils components of the aerial part and roots of Sphallerocarpus gracilis from Buryatian flora studied for the first time. The main components of the essential oils of the aerial part are geranyl tiglate (7.56%) and apiol (71.83%); the roots are γ-terpinene (45.17%), p-cymene (9.38%) and trans-asarone (13.29%). Conclusion. It has been shown that the aerial part of S. gracilis is a rich source of apiol, while the roots – compounds of monoterpene nature.

The Role of Fatty Acids from Plant Surfaces in the Infectivity of Colletotrichum fioriniae.

Aqueous extracts derived from flowers stimulate germination, secondary conidiation, and appressorial formation of various latent fruit rotting fungi. Even raindrops passing over flowers accumulate sufficient activity to influence the infectivity of fruit rotting fungi. Using a spore germination bioassay, high levels of bioactivity were found in chloroform extracts from plant tissues, implicating the nonpolar components of the cuticle. The fatty acid (FA) and fatty acid methyl ester (FAME) composition (C9-C20) of blueberry and cranberry tissues as well as aqueous flower extracts were characterized using a gas chromatography-mass spectrometry (GC-MS) method. The FAs and FAMEs found in the plant extracts were then tested for bioactivity using a spore germination bioassay. The C16:0 and C18:2 FAs and FAMEs, as well as the C18:0 FAME and the C20:0 FA, all stimulated appressorial formation while the C10:0 FA stimulated secondary conidiation. The C10:0 and C16:0 FAs were the only two bioactive components also identified from the aqueous floral extracts of both blueberry and cranberry and are therefore considered as contributors to the bioactivity observed in these extracts. The aqueous extracts from surfaces other than flowers showed little or no activity, and it is speculated that the movement of FAs may be related to the level of polymerization and cutin polyester development in flowers versus other plant organs. This study highlights the importance of the bloom period for infection and that the apparent effects on host susceptibility may therefore depend on the availability of specific FAs or combinations thereof.

A Novel Validated HS-GC-MS method for the trace level determination of Acetyl chloride as Isopropyl acetate in various anti-cancer drug substances

A novel, simple and precise headspace gas chromatography-mass spectrometry (HS-GC-MS) method was developed and validated for the determination of acetyl chloride (AC) in various anti-cancer drug substances like bendamustine HCl, Ibrutinib, trifluridine and abemaciclib drug substances. In this methodology, AC reacts with isopropyl alcohol and is converted into isopropyl acetate. Hence AC is quantified as Isopropyl acetate. The lower level of detection was achieved on the capillary GC column (DB-624, Fused silica capillary column; 30 m length; 0.32 mm internal diameter, coated with 6% Cyanopropylphenyl and 94% dimethyl polysiloxane stationary phase of 1.8 μm film thickness) with electron impact ionization (EI) technique by GC-MS in selective ion monitoring (SIM) mode. The mass ions were selected for the quantifier is 63 and the qualifier is 87 for isopropyl acetate. The performance of the method was assessed by evaluating the specificity, linearity, sensitivity, precision, accuracy and robustness experiments. The established limit of detection and limit of quantification values for the AC were 0.1 and 0.3 μg/g, respectively. This developed method was found to be linear with a correlation coefficient is greater than 0.999 for all four drug substances. The average recoveries of AC in bendamustine HCl, ibrutinib, trifluridine and abemaciclib were obtained 106.1, 109.0, 97.4 and 101.6%, respectively. The proposed method was validated successfully as per ICH guidelines. Hence, the proposed method can be routinely used for the quantification of AC in various anti-cancer drug substances.

Discrepancy of Beta-Hydroxybutyrate Measurements between a Blood Meter and GC-MS Methods in Healthy Humans

Ketone salt (KS) supplementation induces temporary nutritional ketosis to achieve potential exercise performance and health benefits. Racemic KS includes both D/L isomers of β-hydroxybutyrate, yet commercially available measurement devices (i.e., blood meters) only measure the D variant. The aim of this study was to investigate the efficacy of a blood meter to measure serum β-hydroxybutyrate in comparison with gas chromatography–mass spectrometry (GC-MS) before and 30 min after consuming a placebo or racemic KS. In this triple-blinded cross-over study, 16 healthy adults were administered either a placebo or KS drink, and the circulating β-hydroxybutyrate concentration was measured at baseline (PRE) and 30 min following consumption (POST) using a blood ketone meter and by GC-MS. Compared to the placebo, both GC-MS and the blood meter obtained significantly greater β-hydroxybutyrate levels from PRE to POST time-points after consuming KS. Additionally, GC-MS results showed significantly higher levels of β-hydroxybutyrate with both the placebo and KS at PRE and POST time-points, as compared to the blood meter. These results indicate that (1) even in the absence of KS, the blood meter yields significantly lower β-hydroxybutyrate values than GC-MS, and (2) the inability of the blood meter to measure L-β-hydroxybutyrate values POST KS warrants the further development of publicly available ketone measurement apparatuses.

Five Different Artemisia L. Species Ethanol Extracts' Phytochemical Composition and Their Antimicrobial and Nematocide Activity.

Among the plants that exhibit significant or established pharmacological activity, the genus Artemisia L. deserves special attention. This genus comprises over 500 species belonging to the largest Asteraceae family. Our study aimed at providing a comprehensive evaluation of the phytochemical composition of the ethanol extracts of five different Artemisia L. species (collected from the southwest of the Russian Federation) and their antimicrobial and nematocide activity as follows: A. annua cv. Novichok., A. dracunculus cv. Smaragd, A. santonica cv. Citral, A. abrotanum cv. Euxin, and A. scoparia cv. Tavrida. The study of the ethanol extracts of the five different Artemisia L. species using the methods of gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-MS/MS) allowed establishing their phytochemical profile. The obtained data on the of five different Artemisia L. species ethanol extracts' phytochemical composition were used to predict the antibacterial and antifungal activity against phytopathogenic microorganisms and nematocidal activity against the free-living soil nematode Caenorhabditis elegans. The major compounds found in the composition of the Artemisia L. ethanol extracts were monoterpenes, sesquiterpenes, flavonoids, flavonoid glycosides, coumarins, and phenolic acids. The antibacterial and antifungal activity of the extracts began to manifest at a concentration of 150 µg/mL. The A. dracunculus cv. Smaragd extract had a selective effect against Gram-positive R. iranicus and B. subtilis bacteria, whereas the A. scoparia cv. Tavrida extract had a selective effect against Gram-negative A. tumefaciens and X. arboricola bacteria and A. solani, R. solani and F. graminearum fungi. The A. annua cv. Novichok, A. dracunculus cv. Smaragd, and A. santonica cv. Citral extracts in the concentration range of 31.3-1000 µg/mL caused the death of nematodes. It was established that A. annua cv. Novichok affects the UNC-63 protein, the molecular target of which is the nicotine receptor of the N-subtype.

Study to determine the chemical constituents, antibacterial ability, and antioxidant activity of the red pepper (Piper Nigrum l.) essential oil in Gia Lai Province, Vietnam

Pepper often contains aromatic components, spicy ingredients, and biologically active ingredients. The common chemical components in pepper are essential oils and alkaloids. Essential oils are abundant in pepper, usually accounting for about 1.5–2.2%. Therefore, this study aimed to primarily analyze the constituents, antioxidant activity, and inhibition test microorganisms which are very essential. By using the gas chromatography-mass spectrometry method, 17 components in red pepper essential oil have been identified, of which nine constituents are hydrocarbons (such as 41.35% monoterpenes and 3.55% sesquiterpenes) and the rest are oxygenated hydrocarbons (36.62% alcohols and 17.75% aldehydes). The red pepper essential oil has strong antibacterial ability against experimental strains of microorganisms such as Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Streptococcus viridians, Escherichia coli, Proteus vulgaris, Salmonella enteritidis, and Aspergillus flavus with an average antibacterial circle diameter of 15.29 mm. Besides, it has also been determined that the antioxidant activity of red pepper essential oils was 37.69±0.12%.

Development of a joint derivatization protocol for the unequivocal identification of the monosaccharide composition in four dendrobium polysaccharides and free monosaccharide by GC-MS.

The determination of monosaccharides is crucial for studying the structure of polysaccharides and the composition of free monosaccharides in living organisms. Based on previous derivatization gas chromatography-mass spectrometry (GC-MS) methods, we aimed to develop a novel analytical protocol for better quantifying monosaccharides. In this study, sugar alcohol acetylation, saccharonitrile acetylation, silylation and a combination of sugar alcohols acetylation and saccharonitrile acetylation were compared. The optimal method was verified with the monosaccharide determination of four polysaccharides and four free monosaccharides from Dendrobium. The results showed that the novel combined derivatization method was superior to the other three methods in terms of content analysis of monosaccharides. Furthermore, it possessed good linearity (all calibration curves showed relative coefficients ≥ 0.999), sensitivity, precision (relative standard deviation < 2%), and accuracy (recovery, 95.7-105%). Finally, the novel method established in this study was successfully employed in determining the monosaccharide composition of four polysaccharides and four free monosaccharide samples from Dendrobium.

Application of Static Headspace GC-MS Method for Selective 1,4-Dioxane Detection in Food Additives.

Efficient detection methods must be developed for 1,4-dioxane due to its suspected status as a human carcinogen, which is highly mobile in food and environmental resources. In this regard, this experiment has been conducted to develop reliable and selective detection and measurement methods by using static headspace (SH) isolation, followed by gas chromatography-mass spectrometry (GC-MS). A new method was developed for determining the spiked 1,4-dioxane contents in a polyethylene glycol 600 (PEG 600). The optimal condition for SH-GC-MS was discussed. The representative ions of 1,4-dioxane and 1,4-dioxane-d8 in the SIM mode of MS are 88 and 96, respectively, and the peaks of the SIM mode were separated and confirmed. The linear range for the method covers 0.25 to 100 mg/L with a coefficient of determination (R2) ≥ 0.999. The method applicability was demonstrated by spike recovery across a variety of food additives (i.e., chlorine bitartrate, choline chloride, polysorbate 20 and 60, and PEG 1000). All spike recovery from the tested samples was in the range of 89.50-102.68% with a precision of 0.44-11.22%. These findings suggest a new analytical method for food safety inspection, and could be applicable for ensuring the safety of foods and environmental and public health on a broad scale.

Antibacterial Activities and Chemical Compounds of Plantago lanceolata (Ribwort Plantain) and Plantago major (Broadleaf Plantain) Leaf Extracts

Background: Plantago lanceolata L. (ribwort plantain) and Plantago major L. (broadleaf plantain) are widely used in ethnobotanical studies and for treating various diseases. This study aims to investigate the antimicrobial activity and chemical compounds of these plants. Methods: The leaf extracts of P. lanceolata and P. major were fractioned using different solvents. The phytochemical screening was carried out by the gas chromatography-mass spectrometry (GC-MS) method. The antibacterial activity of extracts was assessed using the disc diffusion method, and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC) were measured by microtiter-broth dilution method. Results: The dichloromethane leaf extract of P. lanceolata and P. major showed the highest antibacterial activity against Salmonella paratyphi (diameter of the inhibition zone: 18.83 and 20.00 mm, respectively) at 100 mg/mL concentration. The lowest MIC was related to dichloromethane extracts of both plants against S. paratyphi (500 µg/mL). The lowest MBC (1000 µg/mL) was related to the dichloromethane extract of P. major against S. paratyphi. The main compounds of P. lanceolata leaf extracts were bis(2-ethylhexyl) phthalate (41.96%), 1-methoxy-3-(2-hydroxyethyl)nonane (32.69%), bicyclo[3.1.1]heptane, 2,6,6-trimethyl- (1.alpha.,2.beta.,5.alpha.)- (10.45%), and cycloheptasiloxane tetradecamethyl- (27.96% and 31.33%). The main compounds of P. major leaf extracts were eicosane (23.62%), cyclohexasiloxane dodecamethyl- (18.21%), 1-methyl-3-n-propyl-2-pyrazolin-5-one (18.08%), cycloheptasiloxane tetradecamethyl- (33.85%), and 1,2-benzisothiazole-3-acetic acid, methyl ester (34.26%). Conclusion: Fractionation of the methanolic leaf extract of P. lanceolata and P. major can help better isolate active components from these plants. The antibacterial properties of the extracts of two plants may be due to the presence of antibacterial compounds detected in GC-MS.

Strategies of Practical Implementation of Chemical Pre-Lithiation Using Lithium Arene Complex Solutions: A Systematic Study on Silicon-Based Anodes

Currently, Lithium ion batteries (LIBs) are state-of-the-art (SOTA) energy storage systems. There is an urgent need for further improvements in terms of gravimetric and volumetric energy of LIBs, for a successful market penetration of electric vehicles. Therefore, development of advanced negative electrode materials is of high interest. Here, silicon (Si) is a promising active material to replace SOTA graphite due to its ~10-fold higher specific capacity and being also high abundant.However, Si undergoes severe volume changes up to 280% during (de-)lithiation, resulting in fast capacity fading and short cycle life due to the continuous re-formation of the solid electrolyte interphase (SEI), leading to active lithium losses (ALL). In order to counteract ALL, research is focusing on suitable pre-lithiation processes. Among different pre-lithiation methods, chemical pre-lithiation by application of lithium arene complex (LAC) solutions is promising as it is a fast, easy and cost-effective method.In this work, the stability of three different solvents to produce a 4,4’-dimethylbiphenyl (4,4’-DMBP) LAC is investigated via solid phase microextraction gas chromatography-mass spectrometry method (SPME-GC-MS). The optimized LAC solution is used to evaluate the stability of different binder systems with respect to electrode manufacturing. Based on these fundamental insights, different parameters such as the reaction temperature (T) and pre-lithiation time (PL-t) are systematically investigated regarding suitable degrees of pre-lithiation (DOPL) of the negative electrode. DOPLs up to a plateau of 55% can be obtained by using 0.5 M 4,4’-DMBP in tetrahydrofuran (THF) as LAC solution. Higher temperature during the reaction reduces the PL-t until achieving a pre-lithiation plateau. The impact of the parameters T and PL-t towards the electrochemical performance of Si-based LIB full cells is thoroughly investigated. It is shown that this approach improves the cycle life of a silicon nanowire graphite composite negative electrode up to 600% compared to the pristine electrodes

Natural variation in fatty acid composition of diverse Vietnamese rice germplasm

Despite the advantages of rice bran oil in terms of nutrition and healthcare, the knowledge of its fatty acid composition was still limited. A panel of 100 rice varieties generated from the different ecosystems of Vietnam had been used in our study to investigate their fatty acid profile. Using the modern Gas Chromatography-Mass Spectrometry method, five main fatty acids in our rice bran were discovered including myristic (14:0), palmitic (C16:0), stearic (C18:0), oleic (C18:1) and linoleic (C18:2) acids, in which the fatty acids profile were different and specific for each variety. Among the five fatty acids, the essential linoleic fatty acid content was the highest whereas the myristic acid had the lowest content. The genotype G31 (NEP CAM) had been found with the highest linoleic fatty acid content (43.5%) which could be considered a good source of food and potential for breeding. In this study, we also determined the correlation between the five fatty acids (FAs) content in each rice variety and in comparison with different genotypes. A strong positive correlation between palmitic acid content and the ratio of saturated and unsaturated fatty acid (R = 0.98) was obtained in this study. The ratio of saturated and unsaturated fatty acid in Japonica genotypes is lower than Indica (p &lt; 0.001), indicating that Japonica genotypes have more favorable unsaturated FA. Our study's results may have great importance in contributing to future breeding programs to improve fatty acid components in our Vietnamese rice.

A Nationwide Survey and Risk Assessment of Ethyl Carbamate Exposure Due to Daily Intake of Alcoholic Beverages in the Chinese General Population.

Ethyl carbamate (EC) is carcinogenic, and, in China, oral intake of EC mainly occurs as a result of the consumption of alcoholic beverages. To obtain the latest EC intake and risk analysis results for the general population in China, the China National Center for Food Safety Risk Assessment (CFSA) conducted the sixth total diet study (TDS) as a platform to analyze EC contents and exposure due to the intake of alcoholic beverages. A total of 100 sites in 24 provinces were involved in the collection and preparation of alcohol mixture samples for the sixth TDS. There were 261 different types of alcohol collected across the country, based on local dietary menus and consumption survey results. Ultimately, each province prepared a mixed sample by mixing their respective samples according to the percentage of local consumption. The EC levels of these twenty-four mixed samples were determined using our well-validated gas chromatography-mass spectrometry (GC-MS) method. The values ranged from 1.0 μg/kg to 33.8 μg/kg, with 10.1 μg/kg being the mean. China's EC daily intake ranged from 0.001 ng/kg bw/d to 24.56 ng/kg bw/d, with a mean of 3.23 ng/kg bw/d. According to the margin of exposure (MOE), virtually safe dose (VSD), and T25 risk assessments of the carcinogenicity of EC, the mean lifetime cancer risk for the Chinese population was 9.8 × 104, 1.5 × 10-7, and 8.6 × 10-8, respectively. These data show that the carcinogenicity of EC in the general Chinese population due to alcoholic intake is essentially minimal.

An analytical approach to determining pethidine: An investigation of 18 patients’ urine

Pethidine (PET) is an opioid pain-relief medicine with high addiction potential, especially among health professionals. Pethidine is commonly prescribed in Turkey as a pain-relieving medication for operative purposes. Due to its accessibility, low cost, user-friendliness, and effectiveness, PET is often misused by both healthcare professionals and patients. For this reason, analytical determination methods for PET abuse are essential in terms of forensic toxicology. In this study, a fast, reliable, and accurate gas chromatography-mass spectrometry method was developed for the first time in Turkey for the simultaneous detection of PET and its main urinary metabolite norpethidine (NPET). The method was validated in terms of selectivity, linearity, the limit of detection (LOD), the limit of quantification (LOQ), trueness, and precision according to the Scientific Working Group for Forensic Toxicology guidelines. The linear range was between 0.125‐25.00 μg/mL for PET and 1.00–20.00 μg/mL for NPET. The LOD values for PET and NPET were 0.05 µg/mL and 0.49 µg/mL, while the LOQ values were 0.125 µg/mL and 1.00 µg/mL, respectively. Extraction efficiencies were calculated as 113% for PET and 104% for NPET. The intra-assay and inter-assay precision results were within acceptable limits. In the presented study, the validated method was applied to the urine of 18 patients collected at the 1st and 3rd hours after receiving PET. All samples in the study were collected under patients’ consent and in line with ethical guidelines.