VOC Emission Rates from an Indoor Surface Using a Flux Chamber and PTR-MS

Atmospheric Environment, Год журнала: 2024, Номер 338, С. 120817 - 120817

Опубликована: Сен. 12, 2024

Язык: Английский

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Reply on RC1

Опубликована: Янв. 6, 2025

Abstract. Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H₃O⁺) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. Unlike more energetic methods (e.g., electron impact), H₃O⁺ can leave a target VOC molecule mostly intact thus in PTR-MS spectrum be identified by its mass-to-charge ratio corresponding to proton-transfer product (MH⁺). However, ionization, associated chemistry reactor, known generate other ions besides product. The distributions (PIDs) created during include resulting from charge transfer reactions, water clustering, fragmentation, all which create ambiguity when interpreting spectra. A standardized method evaluating quantifying possible influence PIDs on spectra limited part due an incomplete understanding formation mechanisms effects instrument settings measured PIDs, as well reasons instrument-to-instrument variability. We present method, gas-chromatography pre-separation, measurements nearly 100 VOCs different functional types including alcohols, ketones, aldehydes, acids, aromatics, halogens, alkenes. Using this we highlight major contributions cluster fragment oxygenated VOCs. characterize ion-molecule reactor conditions, transmission quadrupole optic tuning, inlet capillary configuration PIDs. find that conditions have strongest impact but voltage differences also affect Through interlaboratory comparison calibration cylinders variability PID production same model across seven participating laboratories. subset laboratories had standard deviations (1 σ) with varied no than 20 % providing constraint predicting instruments operating under conditions. potential misidentification case study restroom air. propose identifying likely constraining Finally, library acquired study, publicly available updated periodically user-provided data continued investigation into

Язык: Английский

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Reply on RC2

Опубликована: Янв. 6, 2025

Abstract. Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H₃O⁺) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. Unlike more energetic methods (e.g., electron impact), H₃O⁺ can leave a target VOC molecule mostly intact thus in PTR-MS spectrum be identified by its mass-to-charge ratio corresponding to proton-transfer product (MH⁺). However, ionization, associated chemistry reactor, known generate other ions besides product. The distributions (PIDs) created during include resulting from charge transfer reactions, water clustering, fragmentation, all which create ambiguity when interpreting spectra. A standardized method evaluating quantifying possible influence PIDs on spectra limited part due an incomplete understanding formation mechanisms effects instrument settings measured PIDs, as well reasons instrument-to-instrument variability. We present method, gas-chromatography pre-separation, measurements nearly 100 VOCs different functional types including alcohols, ketones, aldehydes, acids, aromatics, halogens, alkenes. Using this we highlight major contributions cluster fragment oxygenated VOCs. characterize ion-molecule reactor conditions, transmission quadrupole optic tuning, inlet capillary configuration PIDs. find that conditions have strongest impact but voltage differences also affect Through interlaboratory comparison calibration cylinders variability PID production same model across seven participating laboratories. subset laboratories had standard deviations (1 σ) with varied no than 20 % providing constraint predicting instruments operating under conditions. potential misidentification case study restroom air. propose identifying likely constraining Finally, library acquired study, publicly available updated periodically user-provided data continued investigation into

Язык: Английский

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Formation of late-generation atmospheric compounds inhibited by rapid deposition

Nature Geoscience, Год журнала: 2025, Номер unknown

Опубликована: Фев. 17, 2025

Язык: Английский

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Product ion distributions using H₃O⁺ proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS): mechanisms, transmission effects, and instrument-to-instrument variability

Atmospheric measurement techniques, Год журнала: 2025, Номер 18(4), С. 1013 - 1038

Опубликована: Фев. 27, 2025

Abstract. Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H3O+) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. H3O+ ionization, as well associated chemistry in an ion–molecule reactor, known to generate product distributions (PIDs) that include other ions besides proton-transfer product. We present a method, gas-chromatography pre-separation, quantifying PIDs from PTR-MS measurements nearly 100 VOCs different functional types including alcohols, ketones, aldehydes, acids, aromatics, organohalides, alkenes. characterize instrument configuration effects on find reactor reduced electric field strength (E/N), optic voltage gradients, quadrupole settings have strongest impact measured PIDs. Through interlaboratory comparison calibration cylinders, we characterized variability PID production same model across seven participating laboratories. Product was generally smaller (e.g., < 20 %) with larger contributions > 0.30) but less predictable formed through O2+ NO+ reactions. publicly available library will be updated periodically user-provided data continued investigation into instrument-to-instrument

Язык: Английский

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Enhanced removal of VOCs from wood by coupling extraction with surfactant and, oxidation using ultrasound-activated persulfate

Industrial Crops and Products, Год журнала: 2022, Номер 189, С. 115818 - 115818

Опубликована: Окт. 27, 2022

Язык: Английский

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Speciating volatile organic compounds in indoor air: using in-situ GC to interpret real-time PTR-MS signals

Environmental Science Processes & Impacts, Год журнала: 2024, Номер unknown

Опубликована: Дек. 18, 2024

Gas chromatography paired with proton transfer reaction mass spectrometry allows for a more accurate assessment of gas-phase chemicals in indoor air.

Язык: Английский

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Human Activities Shape Indoor Volatile Chemistry

Environmental Science & Technology Letters, Год журнала: 2023, Номер 10(11), С. 965 - 975

Опубликована: Март 10, 2023

Perception of odors created by volatile molecules is central to human well-being. The chemistry compounds especially important inside the built environment as humans spend increasingly more time indoors. However, a comprehensive understanding composition and behavior indoor semivolatile (volatilome) limited, in part due tremendous complexity fleeting nature these chemical distributions. This study explored volatilome, opposed individual compounds, residence. We mapped spatial distribution volatiles within house traced corresponding temporal volatilome changes. Each activity generated trail volatiles, after habitation was found be distinctly reshaped. Using molecular networking, we how multiple families were affected. portion that has accumulated occupancy appears harmful health than emissions from itself. an consideration for any other with chemistry, such hospitals or office spaces.

Язык: Английский

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Indoor Air Quality Implications of Germicidal 222 nm Light

Опубликована: Май 23, 2023

A known strategy for mitigating the indoor transmission of airborne pathogens, including SARS-CoV-2 virus, is irradiation by germicidal UV light (GUV). particularly promising approach 222 nm from KrCl excimer lamps (GUV222); this inactivates but thought to be far less harmful human skin and eyes than longer-wavelength GUV (e.g., 254 nm). However, potential GUV222 affect composition air has received little experimental study. Here, we conduct a series controlled laboratory experiments, carried out in 150 L Teflon chamber, examine formation oxidants other secondary species GUV222. We show that generates ozone (O3) hydroxyl radicals (OH), both which can react with volatile organic compounds form oxidized aerosol particles. Results are consistent predictions simple box model based on photochemistry. use experimentally-validated simulate effect under more realistic scenarios, spanning range ventilation conditions. demonstrate some conditions, lead levels O3, OH, products substantially elevated relative normal especially when low intensity high. Thus, should used at lowest intensities possible concert ventilation, decreasing pathogens while pollutants environments.

Язык: Английский

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From the HOMEChem frying pan to the outdoor atmosphere: chemical composition, volatility distributions and fate of cooking aerosol

Environmental Science Processes & Impacts, Год журнала: 2022, Номер 25(2), С. 314 - 325

Опубликована: Дек. 7, 2022

Cooking organic aerosol (COA) is frequently observed in urban field studies. Like other forms of aerosol, cooking emissions partition between gas and particle phases; a quantitative understanding the species volatility governing this partitioning essential to model transport fate COA. However, few cooking-specific measurements are available, COA often assumed be semi-volatile. We use from thermodenuder coupled an chemical speciation monitor during HOMEChem study investigate components near-source found that fresh have three components: biomass burning-like component (COABBOA), lower associated with oil (COAoil-2), higher (COAoil-1). provide characteristic mass spectra profiles for these components. develop describe as they dilute through house outdoor atmosphere. show total can misclassified air quality studies semi-volatile proxy due presence substantial bins not generally represented models. Primary thus only primary sources pollution, but also compounds undergo secondary chemistry atmosphere contribute ozone formation aerosol.

Язык: Английский

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