A passive sampler composed of a porous, hydrophobic, and gas-permeable expanded polytetrafluoroethylene (ePTFE) tube was developed to effectively concentrate volatile organic compounds (VOCs) in the air. The ePTFE dosimeter has larger sorbent mass normalized sampling rates (L h) compared with literature. This result suggests that ePTFE dosimeter can effectively detect low level VOCs in less contaminated air, including indoors. The air boundary layer thickness can be neglected when the mass accumulated in sorbent is converted to gas phase VOCs concentrations. The vapor pressure dependent desorption of VOCs from the sorbent was observed and modeling results suggested that this could lead to the underestimation of VOCs concentrations in air. However, the determination of the appropriate sampling time and the consideration of desorption could overcome the underestimation. A proton transfer reaction quadrupole mass spectrometer and passive samplers were deployed simultaneously in a chamber under fluctuating VOCs concentrations in air. The time-weighted average concentrations of ethylbenzene were 0.016, 0.015, and 0.017 g m for 23, 46, and 69 min experimental period, respectively. The average concentration of the real-time analysis was 0.015 g m for 69 min. The results show the ePTFE dosimeter can be used to estimate time weighted VOCs concentrations in air.
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http://dx.doi.org/10.1016/j.scitotenv.2021.149026 | DOI Listing |
Environ Geochem Health
December 2024
School of Mechanical Engineering, Tongji University, Shanghai, 200092, China.
Environmental exposures to volatile organic compound (VOC) mixtures have received increasing attention, yet the risks are under studied. This study aimed to explore the risks of combined exposures to several commonly detected VOCs and to draw attention to the necessity of studying long-term and low-concentration environmental exposure patterns. In this study, we examined the effects of long-term and low-concentration exposures to VOCs like 1,2-dichlorobenzene, benzene, toluene and formaldehyde either alone or in combination on D.
View Article and Find Full Text PDFACS Sens
December 2024
Electronics and Telecommunications Research Institute (ETRI), Daejeon 34129, Republic of Korea.
The increasing prevalence of obesity and metabolic disorders has created a significant demand for personalized devices that can effectively monitor fat metabolism. In this study, we developed an advanced breath analyzer system designed to provide real-time monitoring of exercise-induced fat burning by analyzing volatile organic compounds (VOCs) present in both oral and alveolar breath. Acetone in exhaled breath and β-hydroxybutyric acid (BOHB) in the blood are both biomarkers closely linked to the metabolic fat burning process occurring in the liver, particularly after exercise.
View Article and Find Full Text PDFSci Total Environ
December 2024
UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW, Sydney, NSW 2052, Australia.
Anaerobic co-digestion is emerging as an option for wastewater biosolids management. Variations in treatment parameters can impact odour emissions and, in turn, odour nuisance reduces community acceptance and alternatives for beneficial reuse of biosolids via land application. This study assessed odour emissions from digested sludge and biosolids resulting from the anaerobic co-digestion of wastewater sludge with beverage rejects (beer and cola) and food wastes.
View Article and Find Full Text PDFEnviron Pollut
December 2024
National Astronomical Research Institute of Thailand (Public Organization), Chiang Mai, Thailand. Electronic address:
Volatile organic compounds (VOCs) notably influence air quality, climate and secondary pollutant formation, particularly regions in where urban emissions interact with natural biogenic sources at the interface of urban and natural ecosystems. This study examined the VOC profiles in the Sakaerat dry evergreen forest and the urban area of Nakhon Ratchasima, Thailand, throughout 2023, focusing on seasonal and spatial variations in biogenic and anthropogenic VOCs (BVOCs and AVOCs, respectively). Hydrocarbons, mainly alkanes, dominated VOC compositions, contributing 43.
View Article and Find Full Text PDFEnviron Monit Assess
December 2024
Graduate School of Natural and Applied Sciences, Gazi University, Ankara, 06500, Türkiye.
Ambient Volatile Organic Compounds (VOCs) were investigated to determine their characteristics, Ozone Formation Potentials (OFPs), and health risks in two crude oil production plants (Nusaybin and Egil plants) in southeastern Türkiye. Benzene, toluene, ethylbenzene, m + p xylene, o xylene, and 1,3,5-trimethylbenzene were measured at eight passive sampling points in each plant. Samples were analyzed using gas chromatography coupled with a flame ionization detector and a thermal desorption.
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