Displaying publications 1 - 20 of 65 in total

Abstract:
Sort:
  1. Fluorinated photoreduced graphene oxide with semi-ionic C-F bonds: An effective carbon based photocatalyst for the removal of volatile organic compounds
    Tai XH, Hung WS, Yang TCK, Lai CW, Lee KM, Chen CY, et al.
    Chemosphere, 2024 Feb;349:140890.
    PMID: 38072201 DOI: 10.1016/j.chemosphere.2023.140890
    There is much interest in developing metal-free halogenated graphene such as fluorinated graphene for various catalytic applications. In this work, a fluorine-doped graphene oxide photocatalyst was investigated for photocatalytic oxidation (PCO) of a volatile organic compound (VOC), namely gaseous methanol. The fluorination process of graphene oxide (GO) was carried out via a novel and facile solution-based photoirradiation method. The fluorine atoms were doped on the surface of the GO in a semi-ionic C-F bond configuration. This presence of the semi-ionic C-F bonds induced a dramatic 7-fold increment of the hole charge carrier density of the photocatalyst. The fluorinated GO photocatalyst exhibited excellent photodegradation up to 93.5% or 0.493 h-1 according pseudo-first order kinetics for methanol. In addition, 91.7% of methanol was mineralized into harmless carbon dioxide (CO2) under UV-A irradiation. Furthermore, the photocatalyst demonstrated good stability in five cycles of methanol PCO. Besides methanol, other VOCs such as acetone and formaldehyde were also photodegraded. This work reveals the potential of fluorination in producing effective graphene-based photocatalyst for VOC removal.
    Matched MeSH terms: Volatile Organic Compounds*
  2. Fulltext Silencing the alarm: an insect salivary enzyme closes plant stomata and inhibits volatile release
    Lin PA, Chen Y, Chaverra-Rodriguez D, Heu CC, Zainuddin NB, Sidhu JS, et al.
    New Phytol, 2021 Apr;230(2):793-803.
    PMID: 33459359 DOI: 10.1111/nph.17214
    Herbivore-induced plant volatiles (HIPVs) are widely recognized as an ecologically important defensive response of plants against herbivory. Although the induction of this 'cry for help' has been well documented, only a few studies have investigated the inhibition of HIPVs by herbivores and little is known about whether herbivores have evolved mechanisms to inhibit the release of HIPVs. To examine the role of herbivore effectors in modulating HIPVs and stomatal dynamics, we conducted series of experiments combining pharmacological, surgical, genetic (CRISPR-Cas9) and chemical (GC-MS analysis) approaches. We show that the salivary enzyme, glucose oxidase (GOX), secreted by the caterpillar Helicoverpa zea on leaves, causes stomatal closure in tomato (Solanum lycopersicum) within 5 min, and in both tomato and soybean (Glycine max) for at least 48 h. GOX also inhibits the emission of several HIPVs during feeding by H. zea, including (Z)-3-hexenol, (Z)-jasmone and (Z)-3-hexenyl acetate, which are important airborne signals in plant defenses. Our findings highlight a potential adaptive strategy where an insect herbivore inhibits plant airborne defenses during feeding by exploiting the association between stomatal dynamics and HIPV emission.
    Matched MeSH terms: Volatile Organic Compounds*
  3. Fulltext Real-time IoT-powered AI system for monitoring and forecasting of air pollution in industrial environment
    Ramadan MNA, Ali MAH, Khoo SY, Alkhedher M, Alherbawi M
    Ecotoxicol Environ Saf, 2024 Sep 15;283:116856.
    PMID: 39151373 DOI: 10.1016/j.ecoenv.2024.116856
    Air pollution in industrial environments, particularly in the chrome plating process, poses significant health risks to workers due to high concentrations of hazardous pollutants. Exposure to substances like hexavalent chromium, volatile organic compounds (VOCs), and particulate matter can lead to severe health issues, including respiratory problems and lung cancer. Continuous monitoring and timely intervention are crucial to mitigate these risks. Traditional air quality monitoring methods often lack real-time data analysis and predictive capabilities, limiting their effectiveness in addressing pollution hazards proactively. This paper introduces a real-time air pollution monitoring and forecasting system specifically designed for the chrome plating industry. The system, supported by Internet of Things (IoT) sensors and AI approaches, detects a wide range of air pollutants, including NH3, CO, NO2, CH4, CO2, SO2, O3, PM2.5, and PM10, and provides real-time data on pollutant concentration levels. Data collected by the sensors are processed using LSTM, Random Forest, and Linear Regression models to predict pollution levels. The LSTM model achieved a coefficient of variation (R²) of 99 % and a mean absolute percentage error (MAE) of 0.33 for temperature and humidity forecasting. For PM2.5, the Random Forest model outperformed others, achieving an R² of 84 % and an MAE of 10.11. The system activates factory exhaust fans to circulate air when high pollution levels are predicted to occur in the next hours, allowing for proactive measures to improve air quality before issues arise. This innovative approach demonstrates significant advancements in industrial environmental monitoring, enabling dynamic responses to pollution and improving air quality in industrial settings.
    Matched MeSH terms: Volatile Organic Compounds/analysis
  4. Characterisation of calamansi (Citrus microcarpa). Part II: volatiles, physicochemical properties and non-volatiles in the juice
    Cheong MW, Zhu D, Sng J, Liu SQ, Zhou W, Curran P, et al.
    Food Chem, 2012 Sep 15;134(2):696-703.
    PMID: 23107680 DOI: 10.1016/j.foodchem.2012.02.139
    Calamansi juices from three countries (Malaysia, the Philippines and Vietnam) were characterised through measuring volatiles, physicochemical properties and non-volatiles (sugars, organic acids and phenolic acids). The volatile components of manually squeezed calamansi juices were extracted using dichloromethane and headspace solid-phase microextraction, and then analysed using gas chromatography-mass spectrometry/flame ionisation detector, respectively. A total of 60 volatile compounds were identified. The results indicated that the Vietnam calamansi juice contained the highest amount of volatiles. Two principal components obtained from principal component analysis (PCA) represented 89.65% of the cumulative total variations of the volatiles. Among the non-volatile components, these three calamansi juices could be, to some extent, differentiated according to fructose and glucose concentrations. Hence, this study of calamansi juices could lead to a better understanding of calamansi fruits.
    Matched MeSH terms: Volatile Organic Compounds/analysis*; Volatile Organic Compounds/isolation & purification
  5. Analysis of volatile compounds of Malaysian Tualang (Koompassia excelsa) honey using gas chromatography mass spectrometry
    Nurul Syazana MS, Gan SH, Halim AS, Shah NS, Gan SH, Sukari HA
    Afr J Tradit Complement Altern Med, 2013;10(2):180-8.
    PMID: 24146441
    The constituents of honey's volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-mass spectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended.
    Matched MeSH terms: Volatile Organic Compounds/analysis*
  6. Fulltext Green leaf volatiles: biosynthesis, biological functions and their applications in biotechnology
    ul Hassan MN, Zainal Z, Ismail I
    Plant Biotechnol J, 2015 Aug;13(6):727-39.
    PMID: 25865366 DOI: 10.1111/pbi.12368
    Plants have evolved numerous constitutive and inducible defence mechanisms to cope with biotic and abiotic stresses. These stresses induce the expression of various genes to activate defence-related pathways that result in the release of defence chemicals. One of these defence mechanisms is the oxylipin pathway, which produces jasmonates, divinylethers and green leaf volatiles (GLVs) through the peroxidation of polyunsaturated fatty acids (PUFAs). GLVs have recently emerged as key players in plant defence, plant-plant interactions and plant-insect interactions. Some GLVs inhibit the growth and propagation of plant pathogens, including bacteria, viruses and fungi. In certain cases, GLVs released from plants under herbivore attack can serve as aerial messengers to neighbouring plants and to attract parasitic or parasitoid enemies of the herbivores. The plants that perceive these volatile signals are primed and can then adapt in preparation for the upcoming challenges. Due to their 'green note' odour, GLVs impart aromas and flavours to many natural foods, such as vegetables and fruits, and therefore, they can be exploited in industrial biotechnology. The aim of this study was to review the progress and recent developments in research on the oxylipin pathway, with a specific focus on the biosynthesis and biological functions of GLVs and their applications in industrial biotechnology.
    Matched MeSH terms: Volatile Organic Compounds/metabolism*
  7. Characterization and source profiling of volatile organic compounds in indoor air of private residences in Selangor State, Malaysia
    Sakai N, Yamamoto S, Matsui Y, Khan MF, Latif MT, Ali Mohd M, et al.
    Sci Total Environ, 2017 May 15;586:1279-1286.
    PMID: 28236484 DOI: 10.1016/j.scitotenv.2017.02.139
    Volatile Organic Compounds (VOCs) in indoor air were investigated at 39 private residences in Selangor State, Malaysia to characterize the indoor air quality and to identify pollution sources. Twenty-two VOCs including isomers (14 aldehydes, 5 aromatic hydrocarbons, acetone, trichloroethylene and tetrachloroethylene) were collected by 2 passive samplers for 24h and quantitated using high performance liquid chromatography and gas chromatography mass spectrometry. Source profiling based on benzene/toluene ratio as well as statistical analysis (cluster analysis, bivariate correlation analysis and principal component analysis) was performed to identify pollution sources of the detected VOCs. The VOCs concentrations were compared with regulatory limits of air quality guidelines in WHO/EU, the US, Canada and Japan to clarify the potential health risks to the residents. The 39 residences were classified into 2 groups and 2 ungrouped residences based on the dendrogram in the cluster analysis. Group 1 (n=30) had mainly toluene (6.87±2.19μg/m3), formaldehyde (16.0±10.1μg/m3), acetaldehyde (5.35±4.57μg/m3) and acetone (11.1±5.95μg/m3) at background levels. Group 2 (n=7) had significantly high values of formaldehyde (99.3±10.7μg/m3) and acetone (35.8±12.6μg/m3), and a tendency to have higher values of acetaldehyde (23.7±13.5μg/m3), butyraldehyde (3.35±0.41μg/m3) and isovaleraldehyde (2.30±0.39μg/m3). The 2 ungrouped residences showed particularly high concentrations of BTX (benzene, toluene and xylene: 235μg/m3 in total) or acetone (133μg/m3). The geometric mean value of formaldehyde (19.2μg/m3) exceeded an 8-hour regulatory limit in Canada (9μg/m3), while those in other compounds did not exceed any regulatory limits, although a few residences exceeded at least one regulatory limit of benzene or acetaldehyde. Thus, the VOCs in the private residences were effectively characterized from the limited number of monitoring, and the potential health risks of the VOCs exposure, particularly formaldehyde, should be considered in the study area.
    Matched MeSH terms: Volatile Organic Compounds/analysis*
  8. The synthesis of papaya fruit flavor-related linalool was regulated by CpTPS18 and CpNAC56
    Yao Y, Fu W, Yu Y, Wan S, Zhang W, Ming R
    Plant Reprod, 2024 Sep;37(3):295-308.
    PMID: 37966580 DOI: 10.1007/s00497-023-00486-3
    Papaya is a tropical fruit crop renowned for its rich nutrition, particularly pro-vitamin A. Aroma substances are a major component of fruit quality. While extensive research has been conducted on papaya aroma, there has been a notable lack of in-depth research into a specific class of substances. To bridge this gap, our study focused on analyzing the aroma components of various papaya varieties and their biosynthesis pathways. We compared the volatile components of three papaya varieties with distinct flavors at various ripeness stages. A continuous accumulation of linalool, a volatile compound, in the 'AU9' fruit was detected as it matured. The linalool content reached 56% of the total volatile components upon full ripening. Notably, this percentage was significantly higher than that observed in the other two varieties, 'ZhongBai' and 'Malaysian 7', indicating that linalool serves as the primary component influencing the papaya's odor. Subsequently, we identified CpTPS18, a gene associated with linalool biosynthesis, and demonstrated its ability to catalyze linalool production from GPP and enhance its accumulation through overexpression in papaya fruits, both in vivo and in vitro. Based on transcriptomic analysis, it was predicted that CpMYB56 and CpNAC56 may transcriptionally activate the expression of CpTPS18. Subsequent yeast one-hybrid assay and dual luciferase analysis revealed that CpNAC56 activates the transcription of CpTPS18. Transient overexpression in vivo demonstrated that this gene could upregulate the expression of CpTPS18 and promote linalool accumulation. These results uncovered the primary volatile molecule responsible for papaya fruit odor and identified two major genes influencing its biosynthesis. The genomic resources and information obtained from this study will expedite papaya improvement for fruit quality.
    Matched MeSH terms: Volatile Organic Compounds/metabolism
  9. Key volatile aroma compounds of three black velvet tamarind (Dialium) fruit species
    Lasekan O, See NS
    Food Chem, 2015 Feb 1;168:561-5.
    PMID: 25172748 DOI: 10.1016/j.foodchem.2014.07.112
    Nineteen odour-active compounds were quantified in three black velvet tamarind fruit species. Calculation of the odour activity values (OAVs) of the odorants showed that differences in odour profiles of the tamarinds were mainly caused by linalool, limonene, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, nonanal, and (Z)-3-hexenal. On the basis of their high OAVs, cis-linalool oxide (furanoid), geranyl acetone, and cinnamyl acetate were identified as other potent odorants in the three tamarinds. Sensory studies revealed very distinct aroma profiles, which are characteristic of these types of fruits. While the Dialiumguineense elicited floral, flowery, caramel-like notes, the other two species were dominated by leaf-like, caramel, and green notes.
    Matched MeSH terms: Volatile Organic Compounds/analysis; Volatile Organic Compounds/isolation & purification; Volatile Organic Compounds/chemistry*
  10. Fulltext Development and mining of a volatile organic compound database
    Abdullah AA, Altaf-Ul-Amin M, Ono N, Sato T, Sugiura T, Morita AH, et al.
    Biomed Res Int, 2015;2015:139254.
    PMID: 26495281 DOI: 10.1155/2015/139254
    Volatile organic compounds (VOCs) are small molecules that exhibit high vapor pressure under ambient conditions and have low boiling points. Although VOCs contribute only a small proportion of the total metabolites produced by living organisms, they play an important role in chemical ecology specifically in the biological interactions between organisms and ecosystems. VOCs are also important in the health care field as they are presently used as a biomarker to detect various human diseases. Information on VOCs is scattered in the literature until now; however, there is still no available database describing VOCs and their biological activities. To attain this purpose, we have developed KNApSAcK Metabolite Ecology Database, which contains the information on the relationships between VOCs and their emitting organisms. The KNApSAcK Metabolite Ecology is also linked with the KNApSAcK Core and KNApSAcK Metabolite Activity Database to provide further information on the metabolites and their biological activities. The VOC database can be accessed online.
    Matched MeSH terms: Volatile Organic Compounds/classification; Volatile Organic Compounds/metabolism*; Volatile Organic Compounds/chemistry*
  11. Distinctive exotic flavor and aroma compounds of some exotic tropical fruits and berries: a review
    Lasekan O, Abbas KA
    Crit Rev Food Sci Nutr, 2012;52(8):726-35.
    PMID: 22591343 DOI: 10.1080/10408398.2010.507910
    The characteristic flavor of exotic tropical fruits is one of their most attractive attributes to consumers. In this article, the enormous diversity of exotic fruit flavors is reviewed. Classifying some of the exotic fruits into two classes on the basis of whether esters or terpenes predominate in the aroma was also attempted. Indeed, as far as exotic tropical fruits are concerned, the majority of fruits have terpenes predominating in their aroma profile. Some of the fruits in this group are the Amazonian fruits such as pitanga, umbu-caja, camu-camu, garcinia, and bacuri. The ester group is made up of rambutan, durians, star fruit, snake fruit, acerola, tamarind, sapodilla, genipap, soursop, cashew, melon, jackfruit, and cupuacu respectively. Also, the role of sulphur-volatiles in some of the exotic fruits is detailed.
    Matched MeSH terms: Volatile Organic Compounds/analysis
  12. Revolutionizing indoor air quality monitoring through IoT innovations: a comprehensive systematic review and bibliometric analysis
    Tan H, Othman MHD, Kek HY, Chong WT, Nyakuma BB, Wahab RA, et al.
    Environ Sci Pollut Res Int, 2024 Jul;31(32):44463-44488.
    PMID: 38943001 DOI: 10.1007/s11356-024-34075-2
    Indoor air quality (IAQ) in the built environment is significantly influenced by particulate matter, volatile organic compounds, and air temperature. Recently, the Internet of Things (IoT) has been integrated to improve IAQ and safeguard human health, comfort, and productivity. This review seeks to highlight the potential of IoT integration for monitoring IAQ. Additionally, the paper details progress by researchers in developing IoT/mobile applications for IAQ monitoring, and their transformative impact in smart building, healthcare, predictive maintenance, and real-time data analysis systems. It also outlines the persistent challenges (e.g., data privacy, security, and user acceptability), hampering effective IoT implementation for IAQ monitoring. Lastly, the global developments and research landscape on IoT for IAQ monitoring were examined through bibliometric analysis (BA) of 106 publications indexed in Web of Science from 2015 to 2022. BA revealed the most significant contributing countries are India and Portugal, while the top productive institutions and researchers are Instituto Politecnico da Guarda (10.37% of TP) and Marques Goncalo (15.09% of TP), respectively. Keyword analysis revealed four major research themes: IoT, pollution, monitoring, and health. Overall, this paper provides significant insights for identifying prospective collaborators, benchmark publications, strategic funding, and institutions for future IoT-IAQ researchers.
    Matched MeSH terms: Volatile Organic Compounds/analysis
  13. Metabolite profiling reveals temperature effects on the VOCs and flavonoids of different plant populations
    Goh HH, Khairudin K, Sukiran NA, Normah MN, Baharum SN
    Plant Biol (Stuttg), 2016 Jan;18 Suppl 1:130-9.
    PMID: 26417881 DOI: 10.1111/plb.12403
    Temperature is one of the key factors in limiting the distribution of plants and controlling major metabolic processes. A series of simulated reciprocal transplant experiments were performed to investigate the effect of temperature on plant chemical composition. Polygonum minus of different lowland and highland origin were grown under a controlled environment with different temperature regimes to study the effects on secondary metabolites. We applied gas chromatography-mass spectrometry and liquid chromatography time-of-flight mass spectrometry to identify the chemical compounds. A total of 37 volatile organic compounds and 85 flavonoids were detected, with the largest response observed in the compositional changes of aldehydes and terpenes in highland plants under higher temperature treatment. Significantly less anthocyanidin compounds and larger amounts of flavonols were detected under higher temperature treatment. We also studied natural variation in the different plant populations growing under the same environment and identified compounds unique to each population through metabolite fingerprinting. This study shows that the origin of different plant populations influences the effects of temperature on chemical composition.
    Matched MeSH terms: Volatile Organic Compounds/isolation & purification; Volatile Organic Compounds/metabolism*; Volatile Organic Compounds/chemistry
  14. Fulltext Separation and identification of volatile compounds from liquid cultures of Trichoderma harzianum by GC-MS using three different capillary columns
    Siddiquee S, Cheong BE, Taslima K, Kausar H, Hasan MM
    J Chromatogr Sci, 2012 Apr;50(4):358-67.
    PMID: 22407347 DOI: 10.1093/chromsci/bms012
    A simple, fast, repeatable and less laborious sample preparation protocol was developed and applied for the analysis of biocontrol fungus Trichoderma harzianum strain FA1132 by using gas chromatography-mass spectrometry. The match factors for sample spectra with respect to the mass spectra library of fungal volatile compounds were determined and used to study the complex hydrocarbons and other volatile compounds, which were separated by using different capillary columns with nonpolar, medium polar and high polar stationary phases. To date, more than 278 volatile compounds (with spectral match factor at least 90%) such as normal saturated hydrocarbons (C7-C30), cyclohexane, cyclopentane, fatty acids, alcohols, esters, sulfur-containing compounds, simple pyrane and benzene derivatives have been identified. Most of these compounds have not previously been reported. The method described in this paper is a more convenient research tool for the detection of volatile compounds from the cultures of T. harzianum.
    Matched MeSH terms: Volatile Organic Compounds/analysis*; Volatile Organic Compounds/isolation & purification
  15. Fulltext Nutrient and Sensory Metabolites Profiling of Averrhoa Carambola L. (Starfruit) in the Context of Its Origin and Ripening Stage by GC/MS and Chemometric Analysis
    Ramadan NS, Wessjohann LA, Mocan A, Vodnar DC, El-Sayed NH, El-Toumy SA, et al.
    Molecules, 2020 May 22;25(10).
    PMID: 32455938 DOI: 10.3390/molecules25102423
    Averrhoa carambola L. is a tropical tree with edible fruit that grows at different climatic conditions. Despite its nutritive value and reported health benefits, it is a controversial fruit owing to its rich oxalate content. The present study aimed at investigating aroma and nutrient primary metabolites distribution in A. carambola fruits grown in Indonesia, Malaysia (its endemic origin) versus Egypt, and at different ripening stages. Two techniques were employed to assess volatile and non-volatile metabolites including headspace solid-phase micro-extraction (HS-SPME) joined with gas chromatography coupled with mass-spectrometry (GC-MS) and GC-MS post silylation, respectively. Twenty-four volatiles were detected, with esters amounting for the major class of volatiles in Egyptian fruit at ca. 66%, with methyl caproate as the major component, distinguishing it from other origins. In contrast, aldehydes predominated tropically grown fruits with the ether myristicin found exclusively in these. Primary metabolites profiling led to the identification of 117 metabolites viz. sugars, polyols and organic acids. Fructose (38-48%) and glucose (21-25%) predominated sugar compositions in ripe fruits, whereas sorbitol was the major sugar alcohol (2.4-10.5%) in ripe fruits as well. Oxalic acid, an anti-nutrient with potential health risks, was the major organic acid detected in all the studied fruits (1.7-2.7%), except the Malaysian one (0.07%). It increases upon fruit ripening, including considerable amounts of volatile oxalate esters detected via SPME, and which must not be omitted in total oxalate determinations for safety assessments.
    Matched MeSH terms: Volatile Organic Compounds/metabolism*; Volatile Organic Compounds/chemistry
  16. Fulltext A study on volatile organic compounds emitted by in-vitro lung cancer cultured cells using gas sensor array and SPME-GCMS
    Thriumani R, Zakaria A, Hashim YZH, Jeffree AI, Helmy KM, Kamarudin LM, et al.
    BMC Cancer, 2018 04 02;18(1):362.
    PMID: 29609557 DOI: 10.1186/s12885-018-4235-7
    BACKGROUND: Volatile organic compounds (VOCs) emitted from exhaled breath from human bodies have been proven to be a useful source of information for early lung cancer diagnosis. To date, there are still arguable information on the production and origin of significant VOCs of cancer cells. Thus, this study aims to conduct in-vitro experiments involving related cell lines to verify the capability of VOCs in providing information of the cells.

    METHOD: The performances of e-nose technology with different statistical methods to determine the best classifier were conducted and discussed. The gas sensor study has been complemented using solid phase micro-extraction-gas chromatography mass spectrometry. For this purpose, the lung cancer cells (A549 and Calu-3) and control cell lines, breast cancer cell (MCF7) and non-cancerous lung cell (WI38VA13) were cultured in growth medium.

    RESULTS: This study successfully provided a list of possible volatile organic compounds that can be specific biomarkers for lung cancer, even at the 24th hour of cell growth. Also, the Linear Discriminant Analysis-based One versus All-Support Vector Machine classifier, is able to produce high performance in distinguishing lung cancer from breast cancer cells and normal lung cells.

    CONCLUSION: The findings in this work conclude that the specific VOC released from the cancer cells can act as the odour signature and potentially to be used as non-invasive screening of lung cancer using gas array sensor devices.

    Matched MeSH terms: Volatile Organic Compounds/analysis*; Volatile Organic Compounds/metabolism*
  17. Removal of VOCs from gas streams with double perovskite-type catalysts
    Pan KL, Pan GT, Chong S, Chang MB
    J Environ Sci (China), 2018 Jul;69:205-216.
    PMID: 29941256 DOI: 10.1016/j.jes.2017.10.012
    Double perovskite-type catalysts including La2CoMnO6 and La2CuMnO6 are first evaluated for the effectiveness in removing volatile organic compounds (VOCs), and single perovskites (LaCoO3, LaMnO3, and LaCuO3) are also tested for comparison. All perovskites are tested with the gas hourly space velocity (GHSV) of 30,000hr-1, and the temperature range of 100-600°C for C7H8 removal. Experimental results indicate that double perovskites have better activity if compared with single perovskites. Especially, toluene (C7H8) can be completely oxidized to CO2 at 300°C as La2CoMnO6 is applied. Characterization of catalysts indicates that double perovskites own unique surface properties and are of higher amounts of lattice oxygen, leading to higher activity. Additionally, apparent activation energy of 68kJ/mol is calculated using Mars-van Krevelen model for C7H8 oxidation with La2CoMnO6 as catalyst. For durability test, both La2CoMnO6 and La2CuMnO6 maintain high C7H8 removal efficiencies of 100% and 98%, respectively, at 300°C and 30,000hr-1, and they also show good resistance to CO2 (5%) and H2O(g) (5%) of the gas streams tested. For various VOCs including isopropyl alcohol (C3H8O), ethanal (C2H4O), and ethylene (C2H4) tested, as high as 100% efficiency could be achieved with double perovskite-type catalysts operated at 300-350°C, indicating that double perovskites are promising catalysts for VOCs removal.
    Matched MeSH terms: Volatile Organic Compounds/analysis; Volatile Organic Compounds/chemistry*
  18. Fulltext Use of headspace-gas chromatography-ion mobility spectrometry to detect volatile fingerprints of palm fibre oil and sludge palm oil in samples of crude palm oil
    Othman A, Goggin KA, Tahir NI, Brodrick E, Singh R, Sambanthamurthi R, et al.
    BMC Res Notes, 2019 Apr 16;12(1):229.
    PMID: 30992056 DOI: 10.1186/s13104-019-4263-7
    OBJECTIVE: The addition of residual oils such as palm fibre oil (PFO) and sludge palm oil (SPO) to crude palm oil (CPO) can be problematic within supply chains. PFO is thought to aggravate the accumulation of monochloropropanediols (MCPDs) in CPO, whilst SPO is an acidic by-product of CPO milling and is not fit for human consumption. Traditional targeted techniques to detect such additives are costly, time-consuming and require highly trained operators. Therefore, we seek to assess the use of gas chromatography-ion mobility spectrometry (GC-IMS) for rapid, cost-effective screening of CPO for the presence of characteristic PFO and SPO volatile organic compound (VOC) fingerprints.

    RESULTS: Lab-pressed CPO and commercial dispatch tank (DT) CPO were spiked with PFO and SPO, respectively. Both additives were detectable at concentrations of 1% and 10% (w/w) in spiked lab-pressed CPO, via seven PFO-associated VOCs and 21 SPO-associated VOCs. DT controls could not be distinguished from PFO-spiked DT CPO, suggesting these samples may have already contained low levels of PFO. DT controls were free of SPO. SPO was detected in all SPO-spiked dispatch tank samples by all 21 of the previously distinguished VOCs and had a significant fingerprint consisting of four spectral regions.

    Matched MeSH terms: Volatile Organic Compounds/classification; Volatile Organic Compounds/isolation & purification*
  19. Headspace solid-phase microextraction gas chromatography-mass spectrometry determination of volatile compounds in different varieties of African star apple fruit (Chrysophillum albidum)
    Lasekan O, Khatib A, Juhari H, Patiram P, Lasekan S
    Food Chem, 2013 Dec 1;141(3):2089-97.
    PMID: 23870932 DOI: 10.1016/j.foodchem.2013.05.081
    The volatile compounds in four selected African star apple fruit (Chrysophyllum albidum) varieties were isolated and identified using the headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). A total of 59 compounds were identified. Application of the aroma extract dilution analysis (AEDA) to the aroma distillates from the fruits revealed 45 odour-active compounds in the flavour dilution (FD) factor range of 4-128. Among them, the highest odour activities (FD factors) were determined for methylhexanoate, acetophenone and ethyl dodecanoate. Moreover, aroma lipophilicity appears to reflect molecular conformation. Further analysis of the similarities and differences between the fruit varieties in terms of the key odourants by the application of PLS-DA and PLS-regression coefficient showed strong positive correlation between the very sweet/sweet varieties and 10 key odourants. The odourants included ethyl acetate, acetyl methyl carbinol, methylhexanoate, sabinene, p-cymene, methylbenzoate, ethylbenzoate, geraniol, cis-α-bergomotene, acetophenone, and ethyl dodecanoate.
    Matched MeSH terms: Volatile Organic Compounds/isolation & purification*; Volatile Organic Compounds/chemistry*
  20. Fulltext Plectranthus amboinicus (Lour.) Spreng: Botanical, Phytochemical, Pharmacological and Nutritional Significance
    Arumugam G, Swamy MK, Sinniah UR
    Molecules, 2016 Mar 30;21(4):369.
    PMID: 27043511 DOI: 10.3390/molecules21040369
    Plectranthus amboinicus (Lour.) Spreng. is a perennial herb belonging to the family Lamiaceae which occurs naturally throughout the tropics and warm regions of Africa, Asia and Australia. This herb has therapeutic and nutritional properties attributed to its natural phytochemical compounds which are highly valued in the pharmaceutical industry. Besides, it has horticultural properties due to its aromatic nature and essential oil producing capability. It is widely used in folk medicine to treat conditions like cold, asthma, constipation, headache, cough, fever and skin diseases. The leaves of the plant are often eaten raw or used as flavoring agents, or incorporated as ingredients in the preparation of traditional food. The literature survey revealed the occurrence 76 volatiles and 30 non-volatile compounds belonging to different classes of phytochemicals such as monoterpenoids, diterpenoids, triterpenoids, sesquiterpenoids, phenolics, flavonoids, esters, alcohols and aldehydes. Studies have cited numerous pharmacological properties including antimicrobial, antiinflammatory, antitumor, wound healing, anti-epileptic, larvicidal, antioxidant and analgesic activities. Also, it has been found to be effective against respiratory, cardiovascular, oral, skin, digestive and urinary diseases. Yet, scientific validation of many other traditional uses would be appreciated, mainly to discover and authenticate novel bioactive compounds from this herb. This review article provides comprehensive information on the botany, phytochemistry, pharmacology and nutritional importance of P. amboinicus essential oil and its various solvent extracts. This article allows researchers to further explore the further potential of this multi-utility herb for various biomedical applications.
    Matched MeSH terms: Volatile Organic Compounds/therapeutic use*; Volatile Organic Compounds/chemistry*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links