scholarly journals A compact PTR-ToF-MS instrument for airborne measurements of volatile organic compounds at high spatiotemporal resolution

2014 ◽  
Vol 7 (11) ◽  
pp. 3763-3772 ◽  
Author(s):  
M. Müller ◽  
T. Mikoviny ◽  
S. Feil ◽  
S. Haidacher ◽  
G. Hanel ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Proton Transfer Reaction ◽  
Horizontal Resolution ◽  
Resolving Power ◽  
Spatiotemporal Resolution ◽  
Airborne Measurements ◽  
New Instrument ◽  
Volatile Organic ◽  
Tof Ms

Abstract. Herein, we report on the development of a compact proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) for airborne measurements of volatile organic compounds (VOCs). The new instrument resolves isobaric ions with a mass resolving power (m/Δm) of ~1000, provides accurate m/z measurements (Δm < 3 mDa), records full mass spectra at 1 Hz and thus overcomes some of the major analytical deficiencies of quadrupole-MS-based airborne instruments. 1 Hz detection limits for biogenic VOCs (isoprene, α total monoterpenes), aromatic VOCs (benzene, toluene, xylenes) and ketones (acetone, methyl ethyl ketone) range from 0.05 to 0.12 ppbV, making the instrument well-suited for fast measurements of abundant VOCs in the continental boundary layer. The instrument detects and quantifies VOCs in locally confined plumes (< 1 km), which improves our capability of characterizing emission sources and atmospheric processing within plumes. A deployment during the NASA 2013 DISCOVER-AQ mission generated high vertical- and horizontal-resolution in situ data of VOCs and ammonia for the validation of satellite retrievals and chemistry transport models.

scholarly journals Measurements of volatile organic compounds over West Africa

2010 ◽  
Vol 10 (2) ◽  
pp. 3861-3892 ◽  
Author(s):  
J. G. Murphy ◽  
D. E. Oram ◽  
C. E. Reeves
Keyword(s):  
Boundary Layer ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Marine Boundary Layer ◽  
Deep Convection ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
High Time Resolution ◽  
Airborne Measurements ◽  
Volatile Organic

Abstract. In this paper we describe measurements of volatile organic compounds (VOCs) made using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) aboard the UK Facility for Atmospheric Airborne Measurements during the African Monsoon Multidisciplinary Analyses (AMMA) campaign. Observations were made during approximately 85 h of flying time between 17 July and 17 August 2006, above an area between 4° N and 18° N and 3° W and 4° E, encompassing ocean, mosaic forest, and the Sahel desert. High time resolution observations of counts at mass to charge (m/z) ratios of 42, 59, 69, 71, and 79 were used to calculate mixing ratios of acetonitrile, acetone, isoprene, the sum of methyl vinyl ketone and methacrolein, and benzene, respectively using laboratory-derived humidity-dependent calibration factors. Strong spatial associations between vegetation and isoprene and its oxidation products were observed in the boundary layer, consistent with biogenic emissions followed by rapid atmospheric oxidation. Acetonitrile, benzene, and acetone were all enhanced in airmasses which had been heavily influenced by biomass burning. Benzene and acetone were also elevated in airmasses with urban influence from cities such as Lagos, Cotonou, and Niamey. The observations provide evidence that both deep convection and mixing associated with fair-weather cumulus were responsible for vertical redistribution of VOCs emitted from the surface. Profiles over the ocean showed a depletion of acetone in the marine boundary layer, but no significant decrease for acetonitrile.

scholarly journals Measurements of volatile organic compounds over West Africa

2010 ◽  
Vol 10 (12) ◽  
pp. 5281-5294 ◽  
Author(s):  
J. G. Murphy ◽  
D. E. Oram ◽  
C. E. Reeves
Keyword(s):  
Boundary Layer ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Marine Boundary Layer ◽  
Deep Convection ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
High Time Resolution ◽  
Airborne Measurements ◽  
Volatile Organic

Abstract. In this paper we describe measurements of volatile organic compounds (VOC) made using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) aboard the UK Facility for Atmospheric Airborne Measurements during the African Monsoon Multidisciplinary Analyses (AMMA) campaign. Observations were made during approximately 85 h of flying time between 17 July and 17 August 2006, above an area between 4° N and 18° N and 3° W and 4° E, encompassing ocean, mosaic forest, and the Sahel desert. High time resolution observations of counts at mass to charge (m/z) ratios of 42, 59, 69, 71, and 79 were used to calculate mixing ratios of acetonitrile, acetone, isoprene, the sum of methyl vinyl ketone and methacrolein, and benzene respectively using laboratory-derived humidity-dependent calibration factors. Strong spatial associations between vegetation and isoprene and its oxidation products were observed in the boundary layer, consistent with biogenic emissions followed by rapid atmospheric oxidation. Acetonitrile, benzene, and acetone were all enhanced in airmasses which had been heavily influenced by biomass burning. Benzene and acetone were also elevated in airmasses with urban influence from cities such as Lagos, Cotonou, and Niamey. The observations provide evidence that both deep convection and mixing associated with fair-weather cumulus were responsible for vertical redistribution of VOC emitted from the surface. Profiles over the ocean showed a depletion of acetone in the marine boundary layer, but no significant decrease for acetonitrile.

scholarly journals A compact PTR-ToF-MS instrument for airborne measurements of VOCs at high spatio-temporal resolution

2014 ◽  
Vol 7 (6) ◽  
pp. 5533-5558 ◽  
Author(s):  
M. Müller ◽  
T. Mikoviny ◽  
S. Feil ◽  
S. Haidacher ◽  
G. Hanel ◽  
...  
Keyword(s):  
Proton Transfer Reaction ◽  
Horizontal Resolution ◽  
Resolving Power ◽  
Airborne Measurements ◽  
In Situ Data ◽  
Atmospheric Processing ◽  
New Instrument ◽  
Mass Resolving Power ◽  
Benzene Toluene ◽  
Spatio Temporal

Abstract. Herein, we report on the development of a compact proton-transfer-reaction time-of-flight mass spectrometer for airborne measurements of volatile organic compounds (VOCs). The new instrument resolves isobaric ions with a mass resolving power (m/Δm) of ~ 1000, provides accurate m/z measurements (Δm < 3 mDa), records full mass spectra at 1 Hz and thus overcomes some of the major analytical deficiencies of quadrupole-MS based airborne instruments. 1 Hz detection limits for biogenic VOCs (isoprene, α-pinene), aromatic VOCs (benzene, toluene, xylenes) and ketones (acetone, methyl ethyl ketone) range from 0.05 to 0.12 ppbV, making the instrument well-suited for fast measurements in the continental boundary layer. The instrument detects and quantifies VOCs in locally confined plumes (< 1km) which improves our capability of characterizing emission sources and atmospheric processing within plumes. A deployment during the NASA 2013 DISCOVER-AQ mission generated high vertical and horizontal resolution in situ data of VOCs and ammonia for validation of satellite retrievals and chemistry transport models.

scholarly journals Source characterization of volatile organic compounds measured by PTR-ToF-MS in Delhi, India

2020 ◽  
Author(s):  
Liwei Wang ◽  
Jay G. Slowik ◽  
Nidhi Tripathi ◽  
Deepika Bhattu ◽  
Pragati Rai ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Solid Fuel ◽  
Proton Transfer Reaction ◽  
Fuel Combustion ◽  
Source Characterization ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Solid Fuel Combustion ◽  
Tof Ms

Abstract. Characteristics and sources of volatile organic compounds (VOCs) were investigated with highly time-resolved simultaneous measurements by two proton-transfer-reaction time-of-flight mass spectrometers (PTR-ToF-MS) at an urban and a suburban site in New Delhi, India from January to March 2018. During the measurement period, high mixing ratios of VOCs and trace gases were observed, with high nocturnal mixing ratios and strong day-night variations. The positive matrix factorization (PMF) receptor model was applied separately to the two sites, and six major factors of VOCs were identified at both sites, i.e., two factors related to traffic emissions, two to solid fuel combustion, and two secondary factors. At the urban IITD site, traffic-related emissions comprising mostly mono-aromatic compounds were the dominant sources, contributing 56.6 % of the total mixing ratio, compared to 36.0 % at the suburban MRIU site. Emissions from various solid fuel combustion processes, particularly in the night, were identified as a significant source of aromatics, phenols and furans at both sites. The secondary factors accounted for 15.9 % of the total VOC concentration at IITD and for 33.6 % at MRIU. They were dominated by oxygenated VOCs and exhibited substantially higher contributions during daytime.

scholarly journals First Eddy Covariance Flux Measurements of Semi Volatile Organic Compounds with the PTR3-TOF-MS

2021 ◽  
Author(s):  
Lukas Fischer ◽  
Martin Breitenlechner ◽  
Eva Canaval ◽  
Wiebke Scholz ◽  
Marcus Striednig ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Eddy Covariance ◽  
Organic Compounds ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
Concentration Data ◽  
Single Digit ◽  
Volatile Organic ◽  
Flux Measurements ◽  
Tof Ms

Abstract. We present first eddy covariance flux measurements with the PTR3-TOF-MS, a novel proton-transfer-reaction mass-spectrometer (PTR-MS). During three weeks in spring 2016 the instrument recorded 10 Hz BVOC data on top of the SMEAR II tower in Hyytiälä, Finland. Flux and concentration data of isoprene, monoterpenes and sesquiterpenes were compared to the literature. Due to the improved instrument sensitivity and a customized “wall less” inlet design we could detect a number of fluxes of semi-volatile and low volatile organic compounds (SVOC and LVOC) with less than single digit picomol/m2/s values for the first time. These compounds include sesquiterpene oxidation products and diterpenes. Daytime diterpene fluxes were in the range of 0.05 to 0.15 picomol/m2/s, which amounts to about 0.25 % to 0.5 % of the daytime sesquiterpene flux above canopy.

scholarly journals Segmented flow coil equilibrator coupled to a proton-transfer-reaction mass spectrometer for measurements of a broad range of volatile organic compounds in seawater

Ocean Science ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 925-940 ◽  
Author(s):  
Charel Wohl ◽  
David Capelle ◽  
Anna Jones ◽  
William T. Sturges ◽  
Philip D. Nightingale ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Exchange ◽  
Proton Transfer ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Reaction Mass ◽  
Segmented Flow ◽  
Volatile Organic

Abstract. We present a technique that utilises a segmented flow coil equilibrator coupled to a proton-transfer-reaction mass spectrometer to measure a broad range of dissolved volatile organic compounds. Thanks to its relatively large surface area for gas exchange, small internal volume, and smooth headspace–water separation, the equilibrator is highly efficient for gas exchange and has a fast response time (under 1 min). The system allows for both continuous and discrete measurements of volatile organic compounds in seawater due to its low sample water flow (100 cm3 min−1) and the ease of changing sample intake. The equilibrator setup is both relatively inexpensive and compact. Hence, it can be easily reproduced and installed on a variety of oceanic platforms, particularly where space is limited. The internal area of the equilibrator is smooth and unreactive. Thus, the segmented flow coil equilibrator is expected to be less sensitive to biofouling and easier to clean than membrane-based equilibration systems. The equilibrator described here fully equilibrates for gases that are similarly soluble or more soluble than toluene and can easily be modified to fully equilibrate for even less soluble gases. The method has been successfully deployed in the Canadian Arctic. Some example data from underway surface water and Niskin bottle measurements in the sea ice zone are presented to illustrate the efficacy of this measurement system.

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