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The ability to image invisible gases has applications in industrial and environmental monitoring settings, but is technologically challenging to embed in a low-cost device. For example, imaging methane gas has applications among gas utility companies for routine pipeline monitoring and storage facility inspection. Video rate gas imaging conveys the direction of dispersal and hence the location of a leak source, helping users to improve their efficiency of response to hazardous events. Conventional approaches to detecting methane gas leaks have mainly been based upon flame ionization detectors, but such technology measures concentration at only a single point, making locating the source of the leak a difficult and slow process. One approach to gas imaging is to use a focal plane array (FPA) to image the methane directly. As an alternative to using a FPA, it is possible to use a single photo-detector and an infrared laser, wavelength tuned to an absorption line of the gas, which is raster scanned over a scene and the resulting backscattered light collected and measured.

This research highlights the chemical composition, antioxidant, anti-inflammatory and anti-proliferative activities of essential oils from leaves of Ocimum basilicum, Ocimum americanum, Hyptis spicigera, Lippia multiflora, Ageratum conyzoides, Eucalyptus camaldulensis and Zingiber officinale. Essential oils were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. Major constituents were α-terpineol (59.78%) and β-caryophyllene (10.54%) for Ocimum basilicum; 1, 8-cineol (31.22%), camphor (12.730%), α-pinene (6.87%) and trans α-bergamotene (5.32%) for Ocimum americanum; β-caryophyllene (21%), α-pinene (20.11%), sabinene (10.26%), β-pinene (9.22%) and α-phellandrene (7.03%) for Hyptis spicigera; p-cymene (25.27%), β-caryophyllene (12.70%), thymol (11.88), γ-terpinene (9.17%) and thymyle acetate (7.64%) for Lippia multiflora; precocene (82.10%)for Ageratum conyzoides; eucalyptol (59.55%), α-pinene (9.17%) and limonene (8.76%) for Eucalyptus camaldulensis; arcurcumene (16.67%), camphene (12.70%), zingiberene (8.40%), β-bisabolene (7.83%) and β-sesquiphellandrène (5.34%) for Zingiber officinale. Antioxidant activities were examined using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. O. basilicum and L. multiflora exhibited the highest antioxidant activity in DPPH and ABTS tests, respectively. Anti-inflammatory properties were evaluated by measuring the inhibition of lipoxygenase activity and essential oil of Z. officinale was the most active. Anti-proliferative effect was assayed by the measurement of MTT on LNCaP and PC-3 prostate cancer cell lines, and SF-763 and SF-767 glioblastoma cell lines. Essential oils from A. conyzoides and L. multiflora were the most active on LNCaP and PC-3 cell lines, respectively. The SF-767 glioblastoma cell line was the most sensitive to O. basilicum and L. multiflora EOs while essential oil of A. conyzoides showed the highest activity on SF-763 cells. Altogether these results justify the use of these plants in traditional medicine in Burkina Faso and open a new field of investigation in the characterization of the molecules involved in anti-proliferative processes.

Oleaginous filamentous fungi grown under the nitrogen limitation, accumulate high amounts of lipids in the form of triacylglycerides (TAGs) with fatty acid profiles similar to plant and fish oils. In this study, we investigate the effect of six phosphorus source concentrations combined with two types of nitrogen substrate (yeast extract and ammonium sulphate), on the biomass formation, lipid production, and fatty acid profile for nine oleaginous Mucoromycota fungi. The analysis of fatty acid profiles was performed by gas chromatography with flame ionization detector (GC-FID) and the lipid yield was estimated gravimetrically. Yeast extract could be used as both nitrogen and phosphorus source, without additional inorganic phosphorus supplementation. The use of inorganic nitrogen source (ammonium sulphate) requires strain-specific optimization of phosphorus source amount to obtain optimal lipid production regarding quantity and fatty acid profiles. Lipid production was decreased in ammonium sulphate-based media when phosphorus source was limited in all strains except for Rhizopus stolonifer. High phosphorus source concentration inhibited the growth of Mortierella fungi. The biomass (22 g/L) and lipid (14 g/L) yield of Umbelopsis vinacea was the highest among all the tested strains.Key points• The strain specific P requirements of Mucoromycota depend on the nature of N source.• Yeast extract leads to consistent biomass and lipid yield and fatty acids profiles.• Umbelopsis vinacea showed the highest biomass (22 g/L) and lipid (14 g/L) yield.• High P source amounts inhibit the growth of Mortierella fungi.

We studied the effect of Silicon (Si) on Casparian band (CB) development, chemical composition of the exodermal CB and Si deposition across the root in the Si accumulators rice and maize and the Si non-accumulator onion. Plants were cultivated in nutrient solution with and without Si supply. The CB development was determined in stained root cross-sections. The outer part of the roots containing the exodermis was isolated after enzymatic treatment. The exodermal suberin was transesterified with MeOH/BF3 and the chemical composition was measured using gas chromatography-mass spectroscopy (GC-MS) and flame ionization detector (GC-FID). Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) was used to determine the Si deposition across root cross sections. Si promoted CB formation in the roots of Si-accumulator and Si non-accumulator species. The exodermal suberin was decreased in rice and maize due to decreased amounts of aromatic suberin fractions. Si did not affect the concentration of lignin and lignin-like polymers in the outer part of rice, maize and onion roots. The highest Si depositions were found in the tissues containing CB. These data along with literature were used to suggest a mechanism how Si promotes the CB development by forming complexes with phenols.

Polycyclic aromatic hydrocarbons are amongst the pollutants of major concern in the terrestrial and aquatic habitats. They are mostly characterised by carcinogenic and non-carcinogenic effects. Distribution and potential health risks of sixteen priority PAHs in the water and sediment samples collected between December 2015 and June 2016 from Algoa Bay, South Africa, were evaluated. Water and sediment samples collected were extracted with liquid–liquid and soxhlet extraction methods, respectively, and then cleaned up using glass column loaded with silica gel. Final concentrations of the target PAHs were determined by gas chromatography interfaced with flame ionization detector. Results indicated that individual PAH concentrations in surface water, bottom water and sediment samples ranged from not detected (ND) to 24.66 µg/L, ND to 22.81 µg/L and ND to 5.23 mg/kg correspondingly. Total PAHs concentrations varied as 12.78–78.94 µg/L, 1.20–90.51 µg/L and 1.17–10.47 mg/kg in the three environmental matrices in that order. The non-carcinogenic risk was generally below 1, whereas risk indices (dermal contact) were above the acceptable limit of 1 × 10−4 in the water column, suggesting possible carcinogenic effects to humans, with adults being the most vulnerable. Similarly, highest contributions to TEQs and MEQs in the sediments were made by benzo(a)pyrene and dibenzo(a,h)anthracene, the two most toxic congeners, signifying the possibility of carcinogenicity and mutagenicity in humans. Diagnostic ratios of PAHs reflect a prevailing pyrogenic input all through. The pollution was albeit moderate, yet regular check is recommended to ensure safe and healthy environment for human and aquatic lives.

Comprehensive characterization of petroleum-derived sulfur compounds is crucial for researching and developing desulfurization catalysts, equipment, and processes. However, the complex composition and low concentration of sulfur compounds in oils make it challenging for molecular-level separation and characterization. In this work, sulfur compounds in the straight-run diesel fraction were selectively separated from the oil by the methylation/demethylation method, effectively yielding high-purity thiophenes and sulfides. Molecular-level compositional and structural characterization of sulfur compounds was accomplished through comprehensive two-dimensional gas chromatography (GC × GC) coupled with time-of-flight mass spectrometry. The separation significantly enhances the detection sensitivity for low-content sulfur compounds, thereby enabling a more comprehensive characterization of their molecular compositions and structures. Sulfur compounds with diverse skeletons and carbon numbers were tentatively characterized, including 1~3 cyclic sulfides, thiophenes, benzothiophenes, dihydrobenzothiophenes, dibenzothiophenes, tetrahydrodibenzothiophenes, phenanthrothiophenes, and benzonaphthothiophenes. Additionally, hundreds of individual sulfur compounds were characterized by mass spectrometry. Quantitative analysis for individual compounds and compound types was conducted using a flame ionization detector. Graphical Abstract

This study compares alternative approaches for analyzing phytocannabinoids in different plant materials. Three chromatographic analytical methods (ultra-high-performance liquid chromatography with tandem mass spectrometric detection and gas chromatography with mass spectrometric and flame ionization detection) were evaluated regarding selectivity, sensitivity, analytical accuracy, and precision. The performance of the methods was compared and all three methods were demonstrated to be appropriate tools for analyzing phytocannabinoids in cannabis. Gas chromatography coupled with mass spectrometric detection showed slightly better accuracy in determining phytocannabinoid acids, which are often difficult to quantify owing to their limited stability. Aspects of sample preparation, such as material homogenization and extraction, were also considered. A single ultrasonic-assisted ethanolic extraction of dried and powdered plant samples of cannabis was shown to be exhaustive for extracting the samples prior to analysis.

Tieguanyin tea is a typical representative of oolong tea in China, and is famous for its orchid-like aroma. Fatty acids are one of the important precursors for aroma production. However, fatty acid contents and compositions in Tieguanyin largely remain undefined. In this study, we quantified the fatty acid composition in Tieguanyin and its offspring by gas chromatography–flame ionization detector, and compared the effects of growth sites and harvest time on the leaf fatty acid composition. The results showed that total fatty acid contents in Tieguanyin fresh leaves were higher than its offspring. Growth sites had significant impacts on fatty acid contents. Tieguanyin grown in Anxi County showed higher total fatty acid contents, and higher ratio of total unsaturated fatty acids to total saturated fatty acids. The fresh leaves in the morning showed higher total fatty acid contents compared to samples harvested in the afternoon or evening, suggesting a dynamic fatty acid degradation during day period. During tea processing, unsaturated fatty acids including linolenic acid, linoleic acid and oleic acid (18:1Δ9c) decreased 13.1%, 13.2% and 84.2%, respectively. The ratio of unsaturated fatty acids to saturated fatty acids still was above 300%. We found that Tieguanyin was a typical 18:3 plant, and the higher ratio of unsaturated fatty acids to saturated fatty acids of Tieguanyin grown in Anxi County may contribute to its characteristics aroma.

In winemaking, wood products alternative to barrels are used to achieve various oenological goals, including rapid release of desirable volatile and polyphenolic compounds, color stabilization, and economic benefits. In this research study, oak wood formats (staves, cubes, and chips) were added to red Nebbiolo wines at two vinification stages: during and after alcoholic fermentation. Aromatic composition was analyzed at racking, after three and seven months of aging. Samples were analyzed by gas chromatography–mass spectrometry (GC–MS) and gas chromatography-flame ionization detector (GC-FID). After seven months, a trained panel assessed the sensory profiles of the wines who varied significantly based on the timing of wood addition and the type of wood used. Higher levels of vanillin and furan compounds were found in wines with wood added after fermentation and in those treated with staves. Wines treated with cubes had elevated benzoic aldehyde levels, while those with chips showed higher levels of whisky lactone, a key molecule for “ boisé ” notes. Sensory analysis revealed greater intensity of vanilla and oak wood descriptors in wines treated with cubes and chips. Cubes particularly enhanced spicy aromas like cloves and pepper, offering a more balanced aroma and sensory profile compared to staves and chips.

The composition of essential oils of Chrysanthemum indicum and C. morifolium were comparatively studied using both Gas Chromatography/Flame ionization Detector (GC/FID) and Gas Chromatography/Mass spectrometry (GC/MS) analyses. The antiviral activity was determined using a plaque reduction assay against three common viruses namely, herpes simplex type-1 (HSV-1), hepatitis A (HAV) and vesicular stomatitis virus (VSV). The antimicrobial activity was assessed using agar diffusion and microdilution methods and the minimum inhibitory concentration (MIC) values were determined. In addition, the anti-mycobacterial evaluation was carried out using the Alamar blue assay and the effect against Helicobacter pylori was investigated. The anti-trypanosomal activity was evaluated using the resazurin method. GC investigations revealed that camphor is the major constituent of both oils accounting for 36.69 and 14.56% in the essential oils from C. indicum and C. morifolium, respectively. C. indicum was biologically more active in all experiments; it exhibited a notable antitrypanosomal activity with an IC50 value equals 45.89 μg/mL and a notable antimicrobial activity versus Streptococcus agalactiae with a MIC value of 62.5 μg/mL. It also inhibited the replication of VSV with an IC50 value of 3.14 μg/mL. Both oils revealed antioxidant potential with IC50 values of 2.21 and 2.59 mg/mL for C. indicum and C. morifolium, respectively. This study provides evidence beyond the traditional use of both Chrysanthemum indicum and C. morifolium as anti-infective agents. Thus they could be used as spices in food and can be incorporated in different food products and pharmaceutical preparations as natural preservatives possessing antioxidant potential.