Collection Of Volatile Organic Compounds Research Articles

A New Methodology for High Spatiotemporal Resolution Measurements of Air Volatile Organic Compounds: From Sampling to Data Deconvolution.

Monitoring of volatile organic compounds (VOCs) in air is crucial for understanding their atmospheric impacts and advancing their emission reduction plans. This study presents an innovative integrated methodology suitable for achieving semireal-time high spatiotemporal resolution three-dimensional measurements of VOCs from ground to hundreds of meters above ground. The methodology integrates an active AirCore sampler, custom-designed for deployment from unmanned aerial vehicles (UAV), a proton-transfer-reaction mass spectrometry (PTR-MS) for sample analysis, and a data deconvolution algorithm for improved time resolution for measurements of multiple VOCs in air. The application of the deconvolution technique significantly improves the signal strength of data from PTR-MS analysis of AirCore samples and enhances their temporal resolution by 4 to 8 times to 4-11 s. A case study demonstrates that the methodology can achieve sample collection and analysis of VOCs within 45 min, resulting in >120-360 spatially resolved data points for each VOC measured and achieving a horizontal resolution of 20-55 m at a UAV flight speed of 5 m/s and a vertical resolution of 5 m. This methodology presents new possibilities for acquiring 3-dimensional spatial distributions of VOC concentrations, effectively tackling the longstanding challenge of characterizing three-dimensional VOC distributions in the lowest portion of the atmospheric boundary layer.

Solvent Extraction of PDMS Tubing as a New Method for the Capture of Volatile Organic Compounds from Headspace.

Polydimethylsiloxane (PDMS) tubing is increasingly being used to collect volatile organic compounds (VOCs) from static biological headspace. However, analysis of VOCs collected using PDMS tubing often deploys thermal desorption, where samples are considered as 'one-offs' and cannot be used in multiple experiments. In this study, we developed a static headspace VOC collection method using PDMS tubing which is solvent-based, meaning that VOC extracts can be used multiple times and can be linked to biological activity. Using a synthetic blend containing a range of known semiochemicals (allyl isothiocyanate, (Z)-3-hexen-1-ol, 1-octen-3-one, nonanal, (E)-anethol, (S)-bornyl acetate, (E)-caryophyllene and pentadecane) with differing chemical and physicochemical properties, VOCs were collected in static headspace by exposure to PDMS tubing with differing doses, sampling times and lengths. In a second experiment, VOCs from oranges were collected using PDMS sampling of static headspace versus dynamic headspace collection. VOCs were eluted with diethyl ether and analysed using gas chromatography - flame ionization detector (GC-FID) and coupled GC - mass spectrometry. GC-FID analysis of collected samples showed that longer PDMS tubes captured significantly greater quantities of compounds than shorter tubes, and that sampling duration significantly altered the recovery of all tested compounds. Moreover, greater quantities of compounds were recovered from closed compared to open systems. Finally, analysis of orange headspace VOCs showed no qualitative differences in VOCs recovered compared to dynamic headspace collections, although quantities sampled using PDMS tubing were lower. In summary, extraction of PDMS tubing with diethyl ether solvent captures VOCs from the headspace of synthetic blends and biological samples, and the resulting extracts can be used for multiple experiments linking VOC content to biological activity.

Development of the gas chromatography/mass spectrometry-based aroma designer capable of modifying volatile chemical compositions in complex odors.

Many volatile organic compounds (VOCs) are used to produce various commercial products with aromas mimicking natural products. The VOCs responsible for aromas have been identified from many natural products. The current major strategy is to analyze chemical compositions and aroma qualities of individual VOCs using gas chromatography/mass spectrometry (GC/MS) and GC-olfactometry. However, such analyses cannot determine whether candidate VOCs contribute to the characteristic aroma in mixtures of many VOCs. In this study, we developed a GC/MS-based VOC collection/omission system that can modify the VOC compositions of samples easily and rapidly. The system is composed of GC/MS with a switching unit that can change gas flow routes between MS and a VOC collection device. We first applied this system to prepare gas samples for omission tests, and the aroma qualities of VOC mixtures with and without some VOCs were evaluated by panelists. If aroma qualities were different between the 2 samples, the omitted VOCs were likely key odorants. By collecting VOCs in a gas bag attached to the collection device and transferring some VOCs to MS, specific VOCs could be omitted easily from the VOC mixture. The system could prepare omission samples without chemical identification, preparation of each VOC, and laborious techniques for mixing VOCs, thus overcoming the limitations of previous methods of sample preparation. Finally, the system was used to prepare artificial aromas by replacing VOC compositions between different samples for screening of key odorants. In conclusion, the system developed here can improve aroma research by identifying key odorants from natural products.

Electrophysiological Responses of Curculio elephas (Coleoptera: Curculionidae) to Chestnut Plant Volatiles

Curculio elephas is an oligophagous insect, attacking fruits of chestnut (Castanea spp.) and oak (Quercus spp.). It is considered one of the most important pests of European chestnut (Castanea sativa) in Europe and it occurs in a continuous range throughout Greece. The aim of this study was to identify the potential volatile organic compounds (VOCs) from chestnut reproductive plant tissues (catkin, nut, and bur) acting as attractants for C. elephas adults to be used for the development of a monitoring system integrating pest management tools. VOCs were sampled in situ during spring and autumn of 2021 and 2022 in different areas of Greece. For the collection and identification of VOCs, the dynamic-headspace technique combined with gas chromatography–mass spectrometry (GC–MS), was employed. In total, 122 compounds from these tissues were detected, with most of them being terpenes (>80%). Further analysis showed that chestnut trees release different VOCs depending on their developmental stage. Antennae of both male and female chestnut weevil adults responded to terpenes, green leaf volatiles, and methyl salicylate. Identification of semiochemicals for manipulating weevils’ behavior will contribute to the development of efficient monitoring tools for the detection and management of this pest.

CRISPR/Cas9-mediated lipoxygenase gene-editing in yellow pea leads to major changes in fatty acid and flavor profiles.

Although pulses are nutritious foods containing high amounts of protein, fiber and phytochemicals, their consumption and use in the food industry have been limited due to the formation of unappealing flavors/aromas described as beany, green, and grassy. Lipoxygenase (LOX) enzymes are prevalent among pulse seeds, and their activity can lead to the formation of specific volatile organic compounds (VOCs) from certain polyunsaturated fatty acids (PUFAs). As a widespread issue in legumes, including soybean, these VOCs have been linked to certain unappealing taste perception of foods containing processed pulse seeds. To address this problem in pea and as proof of principle to promote the wider use of pulses, a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) construct was designed to create null alleles (knockouts) of PsLOX2 which had been implicated in the generation of VOCs in peas. Successful CRISPR/Cas9-mediated LOX gene editing of stable transgenic pea lines (TGP) was confirmed by DNA sequencing of the wild type (WT) and TGP pslox2 mutant lines. These lines were also assessed for LOX activity, PUFA levels, and VOCs. Compared to WT peas, the TGP lines showed a significant reduction (p < 0.05) in LOX activity and in the concentration of key VOCs, including hexanal, 2-hexenal, heptanal, (E)-2-heptenal, (E,E)-2,4-heptadienal, 1-octen-3-ol, octanal, (E)-2-octenal (E,E)-2,4-nonadienal and furan-2-pentyl. The content of two essential PUFAs, linoleic and α-linolenic acids, the known substrates of LOX in plants, was higher in TGP flours, indicating the efficacy of the CRISPR-mediated gene editing in minimizing their oxidation and the further modification of PUFAs and their products. The collection of VOCs from the headspace of ground pea seeds, using a portable eNose also distinguished the TGP and WT lines. Multiple regression analysis showed that LOX activity correlated with the two VOCs, heptanal and (E,E)-2,4-heptadienal in pea flours. Partial Least Squares Regression (PLS-R) plot for selected PUFAs, VOCs, and sensor responses in WT and TGP lines showed distinct clusters for WT and TGP lines. Together this data demonstrates the utility of CRISPR mediated mutagenesis of PsLOX2 to quickly improve aroma and fatty acid (FA) profiles of pea seeds of an elite Canadian variety.

Sector-based volatile organic compound emission characteristics and reduction perspectives for coating materials manufacturing in China

Coating materials manufacturing, with heavy use of organic raw materials and excipients, has become an important industrial source of ambient volatile organic compounds (VOCs). Effective control measures must be developed which rely on a complete understanding of both the current emission characteristics and future emission projections. Thus, a comprehensive whole-process method was proposed and local investigations and measurements were conducted to acquire the material balance-based emission factors (EFs) and sector-based VOC emission characteristics in China. Then, its historical emission trends were evaluated and future reduction perspectives were also projected. The results indicate that: (1) the non-controlled VOC EFs for different coatings were 80 g/kg solvent-based paint, 11 g/kg water-based paint, 49 g/kg varnish, 9 g/kg others (pigment, dyestuff, auxiliary), and 70 g/kg ink, respectively. (2) The VOC emissions increased from 0.34 Gg in 1949 to 872.72 Gg in 2018, and solvent-based paint was always the largest contributor (69–83%). Guangdong attributed the highest emissions (24.1%) in 2018, followed by Jiangsu (10.7%) and Sichuan (10.5%) provinces. The most abundant species were aromatics. (3) Disposal facility efficiency and VOC collection rate together determined the total process treatment efficiency. The disposal efficiency of adapted facilities could reach 90–99%, but the unmaintained or unsuitable facilities are more general and greatly reduced in efficiency. The collection rate could be up to >90% but only averaged about 40%. (4) Improving the treatment efficiency and expanding the market for green paint are the main pathways to reducing VOC emissions, and three scenarios were hereby set with increasing intensities. Compared to the non-controlled scenario, if basic or stringent control measures were fully implemented in China in 2030, the VOC emissions would be reduced by 70% or 81%, respectively.

A low cost, easy-to-assemble, open-source modular mobile sampler design for thermal desorption analysis of breath and environmental VOCs

Exhaled breath vapor contains hundreds of volatile organic compounds (VOCs), which are the byproducts of health and disease metabolism, and they have clinical and diagnostic potential. Simultaneous collection of breath VOCs and background environmental VOCs is important to ensure analyses eliminate exogenous compounds from clinical studies. We present a mobile sampling system to extract gaseous VOCs onto commercially available sorbent-packed thermal desorption tubes. The sampler can be connected to a number of commonly available disposable and reusable sampling bags, in the case of this study, a Tedlar bag containing a breath sample. Alternatively, the inlet can be left open to directly sample room or environmental air when obtaining a background VOC sample. The system contains a screen for the operator to input a desired sample volume. A needle valve allows the operator to control the sample flow rate, which operates with an accuracy of −1.52 ± 0.63% of the desired rate, and consistently generated that rate with 0.12 ± 0.06% error across repeated measures. A flow pump, flow sensor and microcontroller allow volumetric sampling, as opposed to timed sampling, with 0.06 ± 0.06% accuracy in the volume extracted. Four samplers were compared by sampling a standard chemical mixture, which resulted in 6.4 ± 4.7% error across all four replicate modular samplers to extract a given VOC. The samplers were deployed in a clinical setting to collect breath and background/environmental samples, including patients with active SARS-CoV-2 infections, and the device could easily move between rooms and can undergo required disinfection protocols to prevent transmission of pathogens on the case exterior. All components required for assembly are detailed and are made publicly available for non-commercial use, including the microcontroller software. We demonstrate the device collects volatile compounds, including use of chemical standards, and background and breath samples in real use conditions.

A review of whole-process control of industrial volatile organic compounds in China

Volatile organic compounds (VOCs) play an important role in the formation of ground-level ozone and secondary organic aerosol (SOA), and they have been key issues in current air pollution prevention and control in China. Considerable attention has been paid to industrial activities due to their large and relatively complex VOCs emissions. The present research aims to provide a comprehensive review on whole-process control of industrial VOCs, which mainly includes source reduction, collection enhancement and end-pipe treatments. Lower VOCs materials including water-borne ones are the keys to source substitution in industries related to coating and solvent usage, leak detection and repair (LDAR) should be regarded as an efficient means of source reduction in refining, petrochemical and other chemical industries. Several types of VOCs collection methods such as gas-collecting hoods, airtight partitions and others are discussed, and airtight collection at negative pressure yields the best collection efficiency. Current end-pipe treatments like UV oxidation, low-temperature plasma, activated carbon adsorption, combustion, biodegradation, and adsorption-combustion are discussed in detail. Finally, several recommendations are made for future advanced treatment and policy development in industrial VOCs emission control.

Volatile Organic Compounds Analysis as a Potential Novel Screening Tool for Breast Cancer: A Systematic Review.

Introduction:An early diagnosis is crucial in reducing mortality among people who have breast cancer (BC). There is a shortfall of characteristic early clinical symptoms in BC patients, highlighting the importance of investigating new methods for its early detection. A promising novel approach is the analysis of volatile organic compounds (VOCs) produced and emitted through the metabolism of cancer cells.Methods:The purpose of this systematic review is to outline the published research regarding BC-associated VOCs. For this, headspace analysis of VOCs was explored in patient-derived body fluids, animal model-derived fluids, and BC cell lines to identify BC-specific VOCs. A systematic search in PubMed and Web of Science databases was conducted according to the PRISMA guidelines.Results:Thirty-two studies met the criteria for inclusion in this review. Results highlight that VOC analysis can be promising as a potential novel screening tool. However, results of in vivo, in vitro and case-control studies have delivered inconsistent results leading to a lack of inter-matrix consensus between different VOC sampling methods.Discussion:Discrepant VOC results among BC studies have been obtained, highly due to methodological discrepancies. Therefore, methodological issues leading to disparities have been reviewed and recommendations have been made on the standardisation of VOC collection and analysis methods for BC screening, thereby improving future VOC clinical validation studies.

Advances on Collection and Analysis of Volatile Organic Compounds in the Diagnosis of Lung Cancer

肺癌是全球范围内发病率和死亡率最高，对人群健康和生命威胁最大的恶性肿瘤之一。筛查与早诊早治是降低人群肺癌死亡率的有效措施。挥发性有机化合物（volatile organic compounds, VOCs）检测以快捷性、无创性、采样方便成为一种具有广泛前景的检测手段，可用于肺癌的早期发现，病程检测及预后管理。目前国内外涌现出了多种VOCs采集设备及分析技术，本综述主要从VOCs采集技术、分析技术以及在肺癌诊疗中的应用研究进展三方面探讨VOCs研究目前所存在的问题及研究前景。

Research Advances in Allelopathy of Volatile Organic Compounds (VOCs) of Plants

Allelopathy is an ecological phenomenon in which organisms interfere with each other. As a management strategy in agricultural systems, allelopathy can be mainly used to control weeds, resist pests, and disease and improve the interaction of soil nutrition and microorganisms. Volatile organic compounds (VOCs) are allelochemicals volatilized from plants and have been widely demonstrated to have different ecological functions. This review provides the recent advance in the allelopathic effects of VOCs on plants, such as growth, competition, dormancy, resistance of diseases and insect pests, content of reactive oxygen species (ROS), enzyme activity, respiration, and photosynthesis. VOCs also participate in plant-to-plant communication as a signaling substance. The main methods of collection and identification of VOCs are briefly summarized in this article. It also points out the disadvantages of VOCs and suggests potential directions to enhance research and solve mysteries in this emerging area. It is necessary to study the allelopathic mechanisms of plant VOCs so as to provide a theoretical basis for VOC applications. In conclusion, allelopathy of VOCs released by plants is a more economical, environmentally friendly, and effective measure to develop substantial agricultural industry by using the allelopathic effects of plant natural products.

Exhaled volatile organic compounds and lung microbiome in COPD: a pilot randomised controlled trial.

BackgroundBreath analysis is a burgeoning field, with interest in volatile organic compounds (VOCs) as a noninvasive diagnostic tool or an outcome measure, but no randomised controlled trials (RCTs) have yet evaluated this technology in a clinical trial longitudinally. In a pilot RCT, our exploratory objectives were feasibility of measuring VOCs via multiple techniques, assessing relationships between VOCs and Haemophilus colonisation and whether CXCR2 antagonism with danirixin altered lung microbiome composition in individuals with COPD.Method43 participants had VOCs and sputum biomarkers evaluated. VOCs and induced sputum were collected after 6 h of fasting at screening and at days 1, 7 and 14. VOCs were analysed via gas chromatography mass spectrometry (GC-MS), field asymmetric ion mobility spectrometry (FAIMS) and eNose. The primary outcome for these analyses was the relationship between VOCs and Haemophilus abundance determined by 16S rRNA sequencing.ResultsA joint-effects model demonstrated a modest relationship between four exhaled VOCs and Haemophilus relative abundance (R2=0.55) measured only by GC-MS, but not as measured using gas chromtaography FAIMS or eNose. There was considerable variability in absolute quantities of individual VOCs longitudinally.ConclusionsVOC measurement in clinical trials to identify subsets of COPD is feasible, but assessment of new VOC technologies must include concurrent GC-MS validation. Further work to standardise collection of VOCs and measuring a background or “housekeeper” VOC is required to understand and normalise individual VOC quantities.

VOCs Are Relevant Biomarkers of Elicitor-Induced Defences in Grapevine.

Grapevine is susceptible to fungal diseases generally controlled by numerous chemical fungicides. Elicitors of plant defence are a way of reducing the use of these chemicals, but still provide inconsistent efficiency. Easy-to-analyse markers of grapevine responses to elicitors are needed to determine the best conditions for their efficiency and position them in protection strategies. We previously reported that the elicitor sulphated laminarin induced the emission of volatile organic compounds (VOCs) by grapevine leaves. The present study was conducted to characterise and compare VOC emissions in response to other elicitors. Bastid® was first used to test the conditions of VOC collection and analysis. Using SBSE-GC-MS, we detected several VOCs, including the sesquiterpene α-farnesene, in a time-dependent manner. This was correlated with the induction of farnesene synthase gene expression, in parallel with stilbene synthesis (another defence response), and associated to resistance against downy mildew. The other elicitors (Redeli®, Romeo®, Bion®, chitosan, and an oligogalacturonide) induced VOC emission, but with qualitative and quantitative differences. VOC emission thus constitutes a response of grapevine to elicitors of various chemical structures. Therefore, VOC analysis is relevant for studying the impact of environmental factors on grapevine defence responses and optimising the performance of elicitors in vineyards.

On sample preparation methods for fermented beverage VOCs profiling by GCxGC-TOFMS

IntroductionAromas and tastes have crucial influences on the quality of fermented beverages. The determination of aromatic compounds requires global non-targeted profiling of the volatile organic compounds (VOCs) in the beverages. However, experimental VOC profiling result depends on the chosen VOC collection method.ObjectivesThis study aims to observe the impact of using different sample preparation techniques [dynamic headspace (DHS), vortex-assisted liquid–liquid microextraction (VALLME), multiple stir bar sorptive extraction (mSBSE), solid phase extraction (SPE), and solid phase micro-extraction (SPME)] to figure out the most suitable sample preparation protocol for profiling the VOCs from fermented beverages.MethodsFive common sample preparation methods were studied with beer, cider, red wine, and white wine samples. After the sample preparation, collected VOCs were analyzed by two-dimensional gas chromatography coupled with time of flight mass spectrometry (GCxGC-TOFMS).ResultsGCxGC oven parameters can be optimized with the Box–Behnken surface response model and response measure on peak dispersion. Due to the unavoidable column and detector saturation during metabolomic analysis, errors may happen during mass spectrum construction. Profiling results obtained with different sample preparation methods show considerable variance. Common findings occupy a small fraction of total annotated VOCs. For known fermentative aromas, best coverage can be reached by using SPME together with SPE for beer, and VALLME for wine and cider.ConclusionsGCxGC-TOFMS is a promising tool for non-targeted profiling on VOCs from fermented beverages. However, a proper data processing protocol is lacking for metabolomic analysis. Each sample preparation method has a specific profiling spectrum on VOC profiling. The coverage of the VOC metabolome can be improved by combining complementary methods.

Comparative Assessment of Asphalt Volatile Organic Compounds Emission from field to laboratory

The quantifying evaluations of asphalt volatile organic compounds (VOCs) throughout the road construction process are growing concerned since VOCs are widely recognized for its adverse effects on both human health and environmental issues. This paper made a comparison on VOCs emission assessment between actual construction field and laboratory simulation, aiming to verify their research gap at similar applied conditions. Atmospheric sampling pump and adsorption tube were used to record the VOCs samples from practical construction site, involving in hot asphalt storage tank, mixture plant, and paving site. Correspondingly, a sealed simulator for experimental VOCs collection was set-up in laboratory to investigate the VOCs amount released in different temperatures. Moreover, thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was applied to analyze the detailed chemical composition and released quantification of VOCs samples. The results indicated that substance varieties and content in asphalt VOCs had considerable dependence on heating temperature. Both oxygen and thermality will trigger the increasing generation of hydrocarbon derivatives (HYD) in asphalt VOCs. For construction site, the investigated scenarios behaved great difference due to the complexity from on-site factors, however, approximating 74% of aliphatic hydrocarbons (ALH) tested in laboratory were fitted with the main components detected in construction site. Therefore, experimental simulation in laboratory could obtain a workable effect in signalling practical VOCs amount and compositions released in construction sites. This study provided a significant reference in connecting construction sites and laboratory research toward asphalt VOCs quantification. It laid down a basis for further total VOCs emission amount estimation and environmental effect assessment in the life-cycle of asphalt pavement construction, which is little concerned in corresponding research field.

Volatile organic compounds analysis as a potential novel screening tool for colorectal cancer: A systematic review and meta-analysis.

The purpose of this meta-analysis was to assess the usefulness of volatile organic compounds (VOC) as a potential novel biomarker for colorectal cancer (CRC).We systematically searched PubMed, Embase, Web of Science, and Cochrane Library databases for observational studies (published before November 25th, 2019; no language restrictions) comparing the VOC analysis between patients with CRC and healthy controls. We evaluated the pooled sensitivity, specificity, diagnostic odds ratio, positive and negative likelihood ratio, as well as summary receiver operating characteristic curve and area under the curve.We identified a total of 10 observational studies that included 381 patients with CRC and 436 healthy controls. Bivariate analysis yielded a pooled sensitivity of 0.82 (95% confidence interval [CI] = 0.77-0.86), specificity of 0.79 (95% CI = 0.71-0.85), positive likelihood ratio of 3.8 (95% CI = 2.8-5.3), and negative likelihood ratio of 0.23 (95% CI = 0.17-0.30). The area under the curve was 0.87 (95% CI = 0.84-0.90). The pooled diagnostic odds ratio was 17 (95% CI = 10-28). Sensitivity analysis indicated that the pooled results were stabilized. The Deeks' funnel plot asymmetry test (P = .41) suggested no potential publication bias.Our pooled data confirmed the associations between VOC analysis and CRC, highlighting the usefulness of VOC analysis as a potential novel screening tool for CRC. However, standardization of VOC collection and analysis methods for CRC screening is required in future research.

Identification of Allosteric Modifiers of Mosquito Odorant Receptor Function and Odor‐Triggered Behaviors

Insect odorant receptors (ORs) are heteromeric ion channels each consisting of a common subunit, ORco, and one of multiple variable subunits, ORx, to which odorants acting as specific receptor agonists or antagonists bind. In cells expressing the ORco subunit alone, functional homomeric channels are formed that can be activated by specific ORco agonists. We have previously shown that mosquito repellents that inhibit odor‐specific responses of multiple Anopheles gambiae heteromeric receptors are ORco‐specific antagonists. Additionally, the responses of heteromeric receptors induced by ORx‐agonists were significantly enhanced in the presence of an ORco‐agonist (OA), a finding suggesting that OA binding causes structural rearrangements in the liganded ORx heteromers.We are now reporting on the extension of our studies for discovery of A. gambiae ORco agonists and antagonists using an insect cell‐based ORco expression platform that allows fast screening of compound collections. Screening of a collection of volatile organic compounds (VOCs) of natural origin for relevant bioactive ligands resulted in the identification of several hits acting as ORco antagonists. The functional relevance of the identified hits has been established by in vivo repellence assays against Aedes albopictus mosquitoes, which are capable of vectoring a number of infectious agents. Nine newly identified ORco antagonists displayed significant mosquito repellent activities, with three of them causing mosquito anosmia‐like effects similar to those of equivalent doses of the widely used insect repellent DEET. Moreover, binary mixtures of the most active compounds caused stronger repellence effects relative to the single compounds, a finding suggesting the possible existence of different antagonist binding sites on ORco and functional synergies caused by allosteric interactions within the homomer and the heteromers. These results provide proof of concept that natural ORco antagonists may modify olfaction‐based mosquito behaviors in a predicted fashion. Moreover, the screening platform employed in this study yields enhanced possibilities for personal protection against mosquito‐borne infectious diseases.Support or Funding InformationSupported by OPENSCREEN‐GR “An Open‐Access Research Infrastructure of Chemical Biology and Target‐Based Screening Technologies for Human and Animal Health, Agriculture and the Environment” (MIS 5002691) funded under the Action “Reinforcement of the Research and Innovation Infrastructure” of the Operational Program “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014–2020), and LIFE CONOPS (LIFE12 ENV/GR/000466) funded by the European Commission under the program LIFE + Environment Policy and Governance. We thank Asteria Karadima for the repellence test schematic.

Operation and Maintenance of Cost-Effective Volatile Organic Compounds Abatement Alternatives

Presently, volatile organic compounds (VOCs) pollution control in China has entered the deep-water zone, facing difficult challenges. The cost-effectiveness of VOCs abatement alternatives will determine the final environmental benefits. Screening of abatement alternatives with good cost-effectiveness and performance is important to form a sound basis for VOCs emission abatement work to create sustainable and stable alternatives. In this study, 12 typical emission scenarios are set up based on the emission characteristics of pollution sources, such as emission concentration, airflow volume, continuous or intermittent emissions, and fluctuations in concentration. Based on these typical scenarios, the operation costs of current mainstream emission abatement alternatives is estimated, and a cost-effectiveness comparison is made using the unit abatement cost (UAC, yuan·kg-1, VOCs) as the index. The results obtained can provide a reference for choosing appropriate VOCs abatement alternatives according to the characteristics of VOCs emission. Results show that for low concentration VOCs, the UAC of emission abatement is normally more than 8 yuan·kg-1. The concentration in the process plays an important role in reducing UAC. Therefore, the reasonable collection of VOCs gas, resulting in smaller emission volume and higher concentration, has a significant impact on the subsequent emission abatement cost-effectiveness. Enhancing the classification collection of VOCs to improve resource attributes of the recovered VOCs liquid is also an effective way to improve the cost effectiveness of VOCs abatement.

Adsorbent-SERS Technique for Determination of Plant VOCs from Live Cotton Plants and Dried Teas.

We developed a novel substrate for the collection of volatile organic compounds (VOCs) emitted from either living or dried plant material to be analyzed by surface-enhanced Raman spectroscopy (SERS). We demonstrated that this substrate can be utilized to differentiate emissions from blends of three teas, and to differentiate emissions from healthy cotton plants versus caterpillar-infested cotton plants. The substrate we developed can adsorb VOCs in static headspace sampling environments, and VOCs naturally evaporated from three standards were successfully identified by our SERS substrate, showing its ability to differentiate three VOCs and to detect quantitative differences according to collection times. In addition, volatile profiles from plant materials that were either qualitatively different among three teas or quantitatively different in abundance between healthy and infested cotton plants were confirmed by collections on Super-Q resin for dynamic headspace and solid-phase microextraction for static headspace sampling, respectively, followed by gas chromatography to mass spectrometry. Our results indicate that both qualitative and quantitative differences can also be detected by our SERS substrate although we find that the detection of quantitative differences could be improved.

Floral volatiles identification and molecular differentiation of Osmanthus fragrans by neutral desorption extractive atmospheric pressure chemical ionization mass spectrometry

Floral volatiles are commonly present only at trace amounts and can be degraded or lost during vapor collection, which is often challenging from the analytical standpoint. Osmanthus fragrans Lour. is a widely cultivated plant known for the highly distinct fragrance of its flowers. The identification of specific volatile organic compounds (VOCs) and molecular differentiation of O. fragrans without any chemical pretreatment and VOC collection are important. Twenty-eight VOCs released by the flowers from ten different cultivars of O. fragrans were identified using neutral desorption extractive atmospheric pressure chemical ionization mass spectrometry (ND-EAPCI-MS) without any chemical pretreatment or VOC collection. Chemical identification was performed by high-resolution MSn analysis and whenever possible was confirmed by the analysis of standards. According to our literature search, nine of the identified VOCs, 3-buten-2-one, cyclohexadiene, 2-methylfuran, 3-allylcyclohexene, cuminyl alcohol, hotrienol oxide, epoxy-linalool oxide, N-(2-hydroxyethyl) octanamide, and 3-hydroxy-dihydro-β-ionone, have not been reported in O. fragrans in earlier studies. Confident differentiation between ten different cultivars of O. fragrans was achieved by the principal component analysis of the mass spectrometric results. The results of our ND-EAPCI-MS analysis substantially increase our knowledge about the chemistry of the O. fragrans floral fragrance and demonstrate the power of this technique for direct molecular profiling for plant recognition or in biotechnological applications.