Identification of breath volatile organic compounds to distinguish pancreatic adenocarcinoma,pancreatic cystic neoplasm,and patients without pancreatic lesions

BACKGROUND Volatile organic compounds(VOCs)are a promising potential biomarker that may be able to identify the presence of cancers.AIM To identify exhaled breath VOCs that distinguish pancreatic ductal adenocar-cinoma(PDAC)from intraductal papillary mucinous neoplasm(IPMN)and healthy volunteers.METHODS We collected exhaled breath from histologically proven PDAC patients,radiological diagnosis IPMN,and healthy volunteers using the ReCIVA®device between 10/2021-11/2022.VOCs were identified by thermal desorption-gas chromatography/field-asymmetric ion mobility spectrometry and compared between groups.RESULTS A total of 156 participants(44%male,mean age 62.6±10.6)were enrolled(54 PDAC,42 IPMN,and 60 controls).Among the nine VOCs identified,two VOCs that showed differences between groups were dimethyl sulfide[0.73 vs 0.74 vs 0.94 arbitrary units(AU),respectively;P=0.008]and acetone dimers(3.95 vs 4.49 vs 5.19 AU,respectively;P<0.001).After adjusting for the imbalance parameters,PDAC showed higher dimethyl sulfide levels than the control and IPMN groups,with adjusted odds ratio(aOR)of 6.98(95%CI:1.15-42.17)and 4.56(1.03-20.20),respectively(P<0.05 both).Acetone dimer levels were also higher in PDAC compared to controls and IPMN(aOR:5.12(1.80-14.57)and aOR:3.35(1.47-7.63),respectively(P<0.05 both).Acetone dimer,but not dimethyl sulfide,performed better than CA19-9 in PDAC diagnosis(AUROC 0.910 vs 0.796).The AUROC of acetone dimer increased to 0.936 when combined with CA19-9,which was better than CA19-9 alone(P<0.05).CONCLUSION Dimethyl sulfide and acetone dimer are VOCs that potentially distinguish PDAC from IPMN and healthy participants.Additional prospective studies are required to validate these findings.

Advanced Technologies for Volatile Organic Compound (VOC) Emission Treatment: An Overview

This paper presents a comprehensive overview of various advanced technologies employed in the treatment of volatile organic compounds(VOCs),which are crucial pollutants in industrial emissions.The study explores different methods,including direct combustion,thermal combustion,catalytic combustion,low-temperature plasma purification,photocatalytic purification,membrane separation,and adsorption methods.Each technology is critically analyzed for its operational principles,efficiency,and applicability under different conditions.Special attention is given to adsorption concentration and catalytic combustion parallel method,highlighting its efficiency in treating low-concentration,high-volume VOC emissions.The paper also delves into the advantages and limitations of each method,providing insights into their effectiveness in various industrial scenarios.The study aims to offer a detailed guide for selecting appropriate VOC treatment technologies,contributing to enhanced environmental protection and sustainable industrial practices.

Exhaled volatile organic compounds for diagnosis and monitoring of asthma

The asthmatic inflammatory process results in the generation of volatile organic compounds(VOCs),which are subsequently secreted by the airways.The study of these elements through gas chromatography-mass spectrometry(GC-MS),which can identify individual molecules with a discriminatory capacity of over 85%,and electronic-Nose(e-NOSE),which is able to perform a quick onboard pattern-recognition analysis of VOCs,has allowed new prospects for non-invasive analysis of the disease in an"omics"approach.In this review,we aim to collect and compare the progress made in VOCs analysis using the two methods and their instrumental characteristics.Studies have described the potential of GC-MS and e-NOSE in a multitude of relevant aspects of the disease in both children and adults,as well as differential diagnosis between asthma and other conditions such as wheezing,cystic fibrosis,COPD,allergic rhinitis and last but not least,the accuracy of these methods compared to other diagnostic tools such as lung function,FeNO and eosinophil count.Due to significant limitations of both methods,it is still necessary to improve and standardize techniques.Currently,e-NOSE appears to be the most promising aid in clinical practice,whereas GC-MS,as the gold standard for the structural analysis of molecules,remains an essential tool in terms of research for further studies on the pathophysiologic pathways of the asthmatic inflammatory process.In conclusion,the study of VOCs through GC-MS and e-NOSE appears to hold promise for the noninvasive diagnosis,assessment,and monitoring of asthma,as well as for further research studies on the disease.

Effective technology for processing industrial volatile organic compounds by the atmospheric pressure microwave plasma torch

In this study,we investigated the abatement of volatile organic compounds(VOCs)by the atmospheric pressure microwave plasma torch(AMPT).To study the treatment efficiency of AMPT,we used the toluene and water-based varnish to simulate VOCs,respectively.By measuring the compounds and contents of the mixture gas before/after the microwave plasma process,we have calculated the treatment efficiency of AMPT.The experimental results show that the treatment efficiency of AMPT for toluene with a concentration of 17.32×10^(4) ppm is up to 60 g/kWh with the removal rate of 86%.For the volatile compounds of water-based varnish,the removal efficiency is up to 97.99%.We have demonstrated the higher potential for VOCs removal of the AMPT process.

Characterization and Source Apportionment of Volatile Organic Compounds in Urban and Suburban Tianjin, China

Tianjin is the third largest megacity and the fastest growth area in China,and consequently faces the problems of surface ozone and haze episodes.This study measures and characterizes volatile organic compounds （VOCs）,which are ozone precursors,to identify their possible sources and evaluate their contribution to ozone formation in urban and suburban Tianjin,China during the HaChi （Haze in China） summer campaign in 2009.A total of 107 species of ambient VOCs were detected,and the average concentrations of VOCs at urban and suburban sites were 92 and 174 ppbv,respectively.Of those,51 species of VOCs were extracted to analyze the possible VOC sources using positive matrix factorization.The identified sources of VOCs were significantly related to vehicular activities,which specifically contributed 60％ to urban and 42％ to suburban VOCs loadings in Tianjin.Industrial emission was the second most prominent source of ambient VOCs in both urban and suburban areas,although the contribution of industry in the suburban area （36％） was much higher than that at the urban area （16％）.We conclude that controlling vehicle emissions should be a top priority for VOC reduction,and that fast industrialization and urbanization causes air pollution to be more complex due to the combined emission of VOCs from industry and daily life,especially in suburban areas.

Measurement of in-vehicle volatile organic compounds under static conditions

The types and quantities of volatile organic compounds （VOCs） inside vehicles have been determined in one new vehicle and two old vehicles under static conditions using the Thermodesorber-Gas Chromatograph/Mass Spectrometer （TD-GC/MS）. Air sampling and analysis was conducted under the requirement of USEPA Method TO-17. A room-size, environment test chamber was utilized to provide stable and accurate control of the required environmental conditions （temperature, humidity, horizontal and vertical airflow velocity, and background VOCs concentration）. Static vehicle testing demonstrated that although the amount of total volatile organic compounds （TVOC） detected within each vehicle was relatively distinct （4940 μg/m^3 in the new vehicle A, 1240 μg/m^3 in used vehicle B, and 132 μg/m^3 in used vehicle C）, toluene, xylene, some aromatic compounds, and various C7-C12 alkanes were among the predominant VOC species in all three vehicles tested. In addition, tetramethyl succinonitrile, possibly derived from foam cushions was detected in vehicle B. The types and quantities of VOCs varied considerably according to various kinds of factors, such as, vehicle age, vehicle model, temperature, air exchange rate, and environment airflow velocity. For example, if the airflow velocity increases from 0.1 m/s to 0.7 m/s, the vehicle＇s air exchange rate increases from 0.15 h^-1 to 0.67 h^-1, and in-vehicle TVOC concentration decreases from 1780 to 1201 μg/m^3.

Release of volatile organic compounds during bio-drying of municipal solid waste

Three treatments were tested to investigate the release concentrations of volatile organic compounds （VOCs） during the bio-drying of municipal solid waste （MSW） by the aerobic and combined hydrolytic-aerobic processes.Results showed that VOCs were largely released in the first 4 days of bio-drying and the dominant components were：dimethyl disulfide,dimethyl sulfide,benzene,2-butanone,limonene and methylene chloride.Thus,the combined hydrolytic-aerobic process was suggested for MSW bio-drying due to fewer aeration quantities in this phase when compared with the aerobic process,and the treatment strategies should base on the key properties of these prominent components.Malodorous sulfur compounds and terpenes were mainly released in the early phase of bio-drying,whereas,two peaks of release concentrations appeared for aromatics and ketones during bio-drying.Notably,for the combined hydrolytic-aerobic processes there were also high concentrations of released aromatics in the shift from hydrolytic to aerobic stages.High concentrations of released chlorinateds were observed in the later phase.For the VOCs produced during MSW bio-drying,i.e.,malodorous sulfur compounds,terpenes and chlorinateds,their release concentrations were mainly determined by production rates;for the VOCs presented initially in MSW,such as aromatics,their transfer and transport in MSW mainly determined the release concentrations.

Emissions of volatile organic compounds from heated needles and twigs of Pinus pumila

A study was conducted to explore the mechanism that emissions of volatile organic compounds（VOC） from heated needles and twigs（200°C,within 15 min） of Pinus pumila affect fire behaviours using the technology of Thermal Desorption-Gas Chromatography-Mass Spectrometry（TD-GC-MS）.The results indicated that the main components of VOC from heated needles and twigs are terpenoids.Most of these terpenoids are monoterpenes.Terpenoids account for 72.93% for the needles and 92.40% for the twigs of the total VOC,and their emission ratios are 61.200 μg·g-1 and 217.060 μg·g-1 respectively.Heated twigs can emit more terpenoids than heated needles because twigs had more volatile oils than needles.In actual fires,these large amounts of terpenoid emissions,especially the monoterpene emissions,have strong effects on fire behaviors that are not only in the initial stage but also in the fast propagation stage of fires.These flammable gases are capable of causing violent combustion and creating crown fires.In addition,if these gases accumulate in an uneven geographical area,there will be a possible for eruptive fires and/or fires flashover to occur.

Differential volatile organic compounds in royal jelly associated with different nectar plants

The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.

Cyclodextrin Polymer Films Optical Waveguide Sensor for Volatile Organic Gas Detection

A sensitive optical waveguide（OWG） sensor which can be used to detect volatile organic compounds（VOCs） was presented.The sensing device（element） was fabricated by means of the immobilization of polyvinyl pyrrolidone（PVP）-cyclodextrin（CD） composite film over a single-mode potassium ion exchanged glass OWG via spin-coating method.The sensor shows higher response to styrene gas than to other VOCs and displays a linear response to styrene gas in a range of 1―1000 μL/L.

A mini-review on the modeling of volatile organic compound adsorption in activated carbons: Equilibrium, dynamics, and heat effects

The research on the adsorption equilibria,kinetics,and increase in process temperature of the volatile organic compound(VOC)adsorption in porous materials ensures safe production,thereby reducing production costs and improving separation efficiency.Therefore,it is critical in predicting the entire adsorption process based on minimal or no experimental input of the adsorbate and adsorbent.We discuss,in this review,the factors that affect the adsorption performance of VOCs in activated carbons,including the adsorption equilibrium,adsorption kinetics,and exotherm during adsorption.Subsequently,the existing prediction models are summarized and compared concerning the adsorption equilibrium,adsorption kinetics,and exothermic process of adsorption.We then propose a new prediction model based on intermolecular interaction and provide an outlook toward the design and manipulation of efficient adsorbents for the VOC system.

Using a biological aerated filter to treat mixed water-borne volatile organic compounds and assessing its emissions

A biological aerated filter （BAF） was evaluated as a fixed-biofilm process to remove water-borne volatile organic compounds （VOCs） from a multiple layer ceramic capacitor （MLCC） manufacturing plant in southern Taiwan. The components of VOC were identified to be toluene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, bromodichloromethane and isopropanol （IPA）. The full-scale BAF was constructed of two separate reactors in series, respectively, using 10- and 15-cm diameter polypropylene balls as the packing materials and a successful preliminary bench-scale experiment was performed to feasibility. Experimental results show that the BAF removed over 90% chemical oxygen demand （COD） from the influent with （1188 ± 605） mg/L of COD. A total organic loading of 2.76 kg biochemical oxygen demand （BOD）/（m3 packing·d） was determined for the packed bed, in which the flow pattern approached that of a mixed flow. A limited VOC concentration of （0.97 ± 0.29） ppmv （as methane） was emitted from the BAF system. Moreover, the emission rate of VOC was calculated using the proposed formula, based on an air-water mass equilibrium relationship, and compared to the simulated results obtained using the Water 9 model. Both estimation approaches of calculation and model simulation revealed that 0.1% IPA （0.0031-0.0037 kg/d） were aerated into a gaseous phase, and 30% to 40% （0.006-0.008 kg/d） of the toluene were aerated.

Performance of rotating drum biofilter for volatile organic compound removal at high organic loading rates

Uneven distribution of volatile organic compounds （VOCs） and biomass, and excess biomass accumulation in some biofilters hinder the application of biofiltration technology. An innovative multilayer rotating drum biofilter （RDB） was developed to correct these problems. The RDB was operated at an empty bed contact time （EBCT） of 30 s and a rotational rate of 1.0 r/min. Diethyl ether was chosen as the model VOC. Performance of the RDB was evaluated at organic loading rates of 32,1, 64.2, 128, and 256 g ether/（m^3·h） （16.06 g ether/（m^3·h） ≈ 1.0 kg chemical oxygen demand （COD）/（m^3·d））. The EBCT and organic loading rates were recorded on the basis of the medium volume. Results show that the ether removal efficiency decreased with an increased VOC loading rate. Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/（m^3·h）. However, when the VOC loading rate was increased to 256 g ether/（m^3·h）, the average removal efficiency dropped to 43%. Nutrient limitation possibly contributed to the drop in ether removal efficiency. High biomass accumulation rate was also observed in the medium at the two higher ether loading rates, and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs.

The sampling apparatus of volatile organic compounds for wood composites

Terpenes, aldehydes, ketones, benzene, and toluene are the important volatileorganic compounds (VOCs) emitted from wood composites. A sampling apparatus of VOCs for woodcomposites was designed and manufactured by Northeast Forestry University in China. Theconcentration of VOCs derived from wood based materials, such as flooring, panel wall, finishing,and furniture can be sampled in a small stainless steel chambers. A protocol is also developed inthis study to sample and measure the new and representative specimens. Preliminary research showedthat the properties of the equipment have good stability. The sort and the amount of differentcomponents can be detected from it. The apparatus is practicable.

Vertical Evolution of Boundary Layer Volatile Organic Compounds in Summer over the North China Plain and the Differences with Winter

The vertical observation of volatile organic compounds(VOCs)is an important means to clarify the mechanisms of ozone formation.To explore the vertical evolution of VOCs in summer,a field campaign using a tethered balloon during summer photochemical pollution was conducted in Shijiazhuang from 8 June to 3 July 2019.A total of 192 samples were collected,23 vertical profiles were obtained,and the concentrations of 87 VOCs were measured.The range of the total VOC concentration was 41-48 ppbv below 600 m.It then slightly increased above 600 m,and rose to 58±52 ppbv at 1000 m.The proportion of alkanes increased with height,while the proportions of alkenes,halohydrocarbons and acetylene decreased.The proportion of aromatics remained almost unchanged.A comparison with the results of a winter field campaign during 8-16 January 2019 showed that the concentrations of all VOCs in winter except for halohydrocarbons were more than twice those in summer.Alkanes accounted for the same proportion in winter and summer.Alkenes,aromatics,and acetylene accounted for higher proportions in winter,while halohydrocarbons accounted for a higher proportion in summer.There were five VOC sources in the vertical direction.The proportions of gasoline vehicular emissions+industrial sources and coal burning were higher in winter.The proportions of biogenic sources+long-range transport,solvent usage,and diesel vehicular emissions were higher in summer.From the surface to 1000 m,the proportion of gasoline vehicular emissions+industrial sources gradually increased.

Emissions of volatile organic compounds and carbonyl compounds from residential coal combustion in China

Emissions of volatile organic compounds （VOCs） and carbonyls from residential coal combustion of five coals with different maturities were studied in a simulated room.The coals were burned in form of honeycomb briquettes in a domestic coal stove,one of the most common fuel/stove combinations in China.Through a dilution system,VOCs and carbonyls samples were collected by canisters and silica-gel cartridges and analyzed by gas chromatography and mass spectrum （GC/MS） and high performance liquid chromatography/ultraviolet （HPLC/UV）,respectively.The results show that the bituminous coals with medium volatile matter content produce the highest emissions while the anthracite yields the lowest.Among the identified carbonyls from the coal smoke,the aromatic compounds （benzaldehyde,2,5-dimethylbenzaldehyde and p-tolualdehyde,m/o-tolualdehyde,benzene,m,p-xylene and trimethyl-benzene） were relatively abundant,which might be due to the molecular structure of the coal.For formaldehyde,aromatic carbonyls and aliphatic alkanes,their concentrations increase up to the maximum values and then decrease with increasing coal maturity.The total carbonyls and VOCs have the same tendency,which was observed for the emission factors of organic carbon （OC）,elemental carbon （EC）,particulate matter （PM） and polycyclic aromatic hydrocarbons （PAHs） detected in the series study.

Effects of Sampling Conditions on Composition and Emission Characteristics of Volatile Organic Compounds in Process Units from Different Refineries

This study investigates the effects of sampling conditions on volatile organic compound(VOC)compositions including different flow restrictors,SUMMA volumes,sampling heights,and wind speeds.Results show that at the six sampling heights the concentrations of main VOC species were slightly different,while the wind speed had a greater impact on the VOC composition of source profiles.With the increase of wind speed,the weighted percentage of high-carbon aromatic hydrocarbons was higher.Besides,there was an extremely different profile between the normal production and shutdown conditions of the delayed coking unit.To compare the emission characteristics of VOCs in various process units of the S and the C refineries,the samples were collected from the catalytic cracking unit,the continuous catalytic reforming unit,and the delayed coking unit.In the continuous catalytic reforming unit,C3-C5 alkanes and low-carbon aromatic hydrocarbons were the main components collected from the S and the C refineries,accounting for 67.1%and 34.9%,respectively.For the delayed coking unit,the total weighted percentage of high carbon C6-C12 alkanes was significantly higher than other units in the S and the C refineries,accounting for 30.5%and 24.4%,respectively.In the catalytic cracking unit,the low-carbon C2-C5 alkanes were abundant,and the weighted percentage of propylene was higher.The emission characteristics obtained were consistent with the processing technology of production units.The results indicate that the VOC emission characteristics from the same production unit in different refineries have similarities and significant differences which are related to the technological process.The emission characteristics of VOCs could provide the data support for source apportionment work in the production units.

Evaluating the Environmental Health Effect of Bamboo-Derived Volatile Organic Compounds through Analysis the Metabolic Indices of the Disorder Animal Model

Objective To identify the bamboo VOCs (volatile organic compounds) effect on animal physiological indices, which associated with human health. Methods GC/MS was used to analyze the volatile organic compounds from Moso bamboo (Phyllostachys heterocyla cv. pubescens). The effect of VOCs on environmental health was evaluated by analyzing the metabolic indices of the type 2 diabetic mouse model. Results Spectra of VOC generated by GC/MS were blasted against an in-house MS library confirming the identification of 33 major components that were manually validated. The relative constituent compounds as a percentage of total VOCs determined were alcohols (34.63%), followed by ether (22.02%), aldehyde (15.84%), ketone (11.47%), ester (4.98%), terpenoid (4.38%), and acids (3.83%). Further experimentation established that the metabolic incidence of the disease can be improved if treated with vanillin, leaf alcohol,β-ionone and methyl salicylate. The effects of these VOCs on type 2 diabetes were evident in the blood lipid and blood glucose levels. Conclusion Our model suggests that VOCs can potentially control the metabolic indices in type 2 diabetes mice. This experiment data also provides the scientific basis for the comprehensive utilization of ornamental bamboos and some reference for other similar study of environmental plants.

Comparision of China's volatile organic compound pollution management:a computable general equilibrium approach

The public health and ecological impacts of volatile organic compound(VOCs) pollution have become a serious problem in China,arousing increasing attention to emissions control.In this context,this paper analyses the effectiveness of VOC reduction policies,namely pollution charges and environmental taxes at the national and industrial sector levels.It uses a computable general equilibrium model,which connects macroeconomic variables with VOC emissions inventory,to simulate the effects of policy scenarios(with 2007 as the reference year).This paper shows that VOC emissions are reduced by 2.2% when a pollution charge equal to the average cost of engineering reduction methods-the traditional approach to regulation in China-is applied.In order to achieve a similar reduction,an 8.9% indirect tax would have to be imposed.It concludes that an environmental tax should be the preferred method of VOC regulation due to its smaller footprint on the macroeconomy.Other policies,such as subsidies,should be used as supplements.

Prediction of Henry Constants and Adsorption Mechanism of Volatile Organic Compounds on Multi-Walled Carbon Nanotubes by Using Support Vector Regression

Support vector regression （SVR） combined with particle swarm optimization for its parameter optimization is employed to establish a model for predicting the Henry constants of multi-walled carbon nanotubes （MWNTs） for adsorption of volatile organic compounds （VOCs）. The prediction performance of SVR is compared with those of the model of theoretical linear salvation energy relationship （TLSER）. By using leave-one-out cross validation of SVR test Henry constants for adsorption of 35 VOCs on MWNTs, the root mean square error is 0.080, the mean absolute percentage error is only 1.19~, and the correlation coefficient （R2） is as high as 0.997. Compared with the results of the TLSER model, it is shown that the estimated errors by SVR are ali smaller than those achieved by TLSER. It reveals that the generalization ability of SVR is superior to that of the TLSER model Meanwhile, multifactor analysis is adopted for investigation of the influences of each molecular structure descriptor on the Henry constants. According to the TLSER model, the adsorption mechanism of adsorption of carbon nanotubes of VOCs is mainly a result of van der Waals and interactions of hydrogen bonds. These can provide the theoretical support for the application of carbon nanotube adsorption of VOCs and can make up for the lack of experimental data.