Measurement of Aromatic Hydrocarbons with the DOAS Technique

Axelsson, Håkan; Eilard, A.; Emanuelsson, Annika; Galle, Bo; Edner, Hans; Ragnarson, P; Kloo, Henrik

doi:10.1366/0003702953965254

Cited by 31 publications

(13 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A correction of oxygen absorption in this study was made by adopting two oxygen spectra nearest the actual optical path length (740 m) in the fitting process and using interpolation (Lee et al, 2005). Atmospheric ozone and sulfur dioxide (SO 2 ) also have an absorption band in the UV spectral region (240-300 nm) and are the most likely to interfere with MAHC (Platt, 1994;Axelsson et al, 1995). They were corrected by incorporating their absorption cross-sections in the fitting routine (Platt, 1994;Axelsson et al, 1995;Volkamer et al, 1998;Kourtidis et al, 2002;Petrakis et al, 2003;Lee et al, 2005).…”

Section: Methodsmentioning

confidence: 99%

“…However, since the 1970s, differential optical absorption spectroscopy (DOAS) has been considered to be a powerful tool for the detection of atmospheric trace species on a real-time basis (Platt, 1994;Axelsson et al, 1995;Barrefors, 1996;Brocco et al, 1997;Virkkula, 1997;Volkamer et al, 1998;Kourtidis et al, 2000Kourtidis et al, , 2002Petrakis et al, 2003). Only a limited number of DOAS studies were able to focus on MAHC measurements due to the interference problem of overlapping of oxygen absorption spectra (Axelsson et al, 1995;Barrefors, 1996;Brocco et al, 1997;Volkamer et al, 1998;Kourtidis et al, 2000Kourtidis et al, , 2002. The mixing ratios of formaldehyde and MAHC as well as O 3 , NO 2 , SO 2 and HONO measured in Seoul, Korea by a long path DOAS (LP-DOAS) during two field campaigns in February and August 2003 are presented in this paper.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of Atmospheric Formaldehyde and Monoaromatic Hydrocarbons using Differential Optical Absorption Spectroscopy during Winter and Summer Intensive Periods in Seoul, Korea

Lee

Kim

Hong

et al. 2005

Water Air Soil Pollut

View full text Add to dashboard Cite

A Long-Path DOAS (LP-DOAS) developed by GIST was used to measure simultaneously atmospheric formaldehyde, monoaromatic hydrocarbons, and other trace gases over 740 and 2000 m beam paths at an urban site in Seoul, Korea during two field campaigns in February and August 2003. The mean concentrations of formaldehyde, benzene, toluene, m-xylene and p-xylene were measured to be 6.32 (±2.41), 0.78 (±0.32), 3.32 (±1.87), 0.52 (±0.24), and 0.38 (±0.18) ppbv during the two measurement periods. Based on the analysis of the ratio of the OH·-NO 2 to OH·-VOCs rate constants, it was possible to draw a conclusion that OH· reacted preferentially with NO 2 during the two measurement periods. Diurnal variation of formaldehyde was not typical of photochemically generated components during the two measurement periods in Seoul. Results from the linear regression fit analysis and diurnal variation of the measured species support that formaldehyde measured could be from primary sources (vehicle exhaust and heating burners) in winter and from primary and secondary sources (photochemical process) in summer. Monoaromatic hydrocarbons were likely emitted from the primary sources.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Measurement of Atmospheric Formaldehyde and Monoaromatic Hydrocarbons using Differential Optical Absorption Spectroscopy during Winter and Summer Intensive Periods in Seoul, Korea

Lee

Kim

Hong

et al. 2005

Water Air Soil Pollut

View full text Add to dashboard Cite

show abstract

“…Since the PTR-MS is not isomer-specific, xylene isomers and ethylbenzene were summed to calculate total C 2 -alkylbenzenes, accounting for the fact that other n-alkyl benzenes and ethylbenzene have similar UV absorption features (Axelsson et al, 1995). A formula was derived to estimate the sum of the C 2 benzenes based on the abundance of the measured isomers and the apparent correction required for DOAS measurements of ethylbenzene to bring them into agreement with the GC-FID analysis of canisters collected at CENICA.…”

Section: Doasmentioning

confidence: 99%

Comparison of aromatic hydrocarbon measurements made by PTR-MS, DOAS and GC-FID during the MCMA 2003 Field Experiment

et al. 2010

View full text Add to dashboard Cite

Abstract.A comparison of aromatic hydrocarbon measurements is reported for the CENICA supersite in the district of Iztapalapa during the Mexico City Metropolitan Area field experiment in April 2003 (MCMA 2003). Data from three different measurement methods were compared: a Proton Transfer Reaction Mass Spectrometer (PTR-MS), long path measurements using a UV Differential Optical Absorption Spectrometer (DOAS), and Gas Chromatography-Flame Ionization analysis (GC-FID) of canister samples. The principle focus was on the comparison between PTR-MS and DOAS data. Lab tests established that the PTR-MS and DOAS calibrations were consistent for a suite of aromatic compounds including benzene, toluene, p-xylene, ethylbenzene, 1,2,4-trimethylbenzene, phenol and styrene. The point sampling measurements by the PTR-MS and GC-FID showed good correlations (r=0.6), and were in reasonable agreement for toluene, C 2 -alkylbenzenes and C 3 -alkylbenzenes. The PTR-MS benzene data were consistently high, indicating interference from ethylbenzene fragmentation for the 145 Td drift field intensity used in the experiment. Correlations between the open-path data measured at 16-m height over a 860-m path length (retroreflector in 430 m distance), and the point measurements collected at 37-m sampling height were best for benzene (r=0.61), and reasonably good for toluene, C 2 -alkylbenzenes, naphthalene, styrene, cresols and phenol (r>0.5). There was good agreement between DOAS and PTR-MS measurements of benzene after correction for the Correspondence to: B. T. Jobson (tjobson@wsu.edu) PTR-MS ethylbenzene interference. Mixing ratios measured by DOAS were on average a factor of 1.7 times greater than the PTR-MS data for toluene, C 2 -alkylbenzenes, naphthalene and styrene. The level of agreement for the toluene data displayed a modest dependence on wind direction, establishing that spatial gradients -horizontal, vertical, or both -in toluene mixing ratios were significant, and up to a factor of 2 despite the fact that all measurements were conducted above roof level. Our analysis highlights a potential problem in defining a VOC sampling strategy that is meaningful for the comparison with photochemical transport models: meaningful measurements require a spatial fetch that is comparable to the grid cell size of models, which is typically a few 10 km 2 . Long-path DOAS measurements inherently average over a larger spatial scale than point measurements. The spatial representativeness can be further increased if observations are conducted outside the surface roughness sublayer, which might require measurements at altitudes as high as 10s of metres above roof level.

show abstract

“…Differential optical absorption spectroscopy (DOAS) has been applied widely for near real-time monitoring of BTEX in ambient air [8,9], but the presence of oxygen, ozone, and several hydrocarbons with similar spectra gives rise to severe interference effects.…”

mentioning

confidence: 99%

Direct atmospheric pressure chemical ionization-tandem mass spectrometry for the continuous real-time trace analysis of benzene, toluene, ethylbenzene, and xylenes in ambient air

Badjagbo

Picard

Moore³

et al. 2009

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Real-time monitoring of benzene, toluene, ethylbenzene, and xylenes (BTEX) in ambient air is essential for the early warning detection associated with the release of these hazardous chemicals and in estimating the potential exposure risks to humans and the environment. We have developed a tandem mass spectrometry (MS/MS) method for continuous real-time determination of ambient trace levels of BTEX. The technique is based on the sampling of air via an atmospheric pressure inlet directly into the atmospheric pressure chemical ionization (APCI) source. The method is linear over four orders of magnitude, with correlation coefficients greater than 0.996. Low limits of detection in the range 1-2 g/m 3 are achieved for BTEX. The reliability of the method was confirmed through the evaluation of quality parameters such as repeatability and reproducibility (relative standard deviation below 8% and 10%, respectively) and accuracy (over 95%). The applicability of this method to real-world samples was evaluated through measurements of BTEX levels in real ambient air samples and results were compared with a reference GC-FID method. This direct APCI-MS/MS method is suitable for real-time analysis of BTEX in ambient air during regulation surveys as well as for the monitoring of industrial processes or emergency situations. B enzene, toluene, ethylbenzene, and isomers of xylene, commonly called BTEX, are volatile organic compounds (VOCs) widely present in petroleum products and added to fuels to increase their octane number [1]. They have toxic health effects depending on duration and levels of exposure [2][3][4][5]. In addition, BTEX in urban air contribute significantly to the smog photochemical reactions leading to ozone formation in the troposphere [6].Several analytical methods have been developed to perform real-time measurements of such compounds in ambient air, and recently, we have published a comprehensive review of the most commonly used on-site methods for continuous real-time monitoring of airborne VOCs [7]. Differential optical absorption spectroscopy (DOAS) has been applied widely for near real-time monitoring of BTEX in ambient air [8,9], but the presence of oxygen, ozone, and several hydrocarbons with similar spectra gives rise to severe interference effects.Proton-transfer reaction/mass spectrometry (PTR-MS) has been used in several field studies for real-time monitoring of atmospheric BTEX [10,11], but there are certain isobaric interferences in the PTR-MS measurements of these hydrocarbons (e.g., notably benzaldehyde).Other direct-air sampling (DS)-MS methods widely used for real-time determination of BTEX in ambient air are low-pressure chemical ionization/tandem mass spectrometry (LPCI-MS/MS) [12,13] and atmospheric pressure chemical ionization/tandem mass spectrometry (APCI-MS/MS) [14,15]. However, they are not yet very conclusive for measuring BTEX in ambient air at low-g/m 3 concentrations [7].The work described in the present article demonstrates the application of a direct APCI-MS/MS system for real-ti...

show abstract

Measurement of Aromatic Hydrocarbons with the DOAS Technique

Cited by 31 publications

References 8 publications

Measurement of Atmospheric Formaldehyde and Monoaromatic Hydrocarbons using Differential Optical Absorption Spectroscopy during Winter and Summer Intensive Periods in Seoul, Korea

Measurement of Atmospheric Formaldehyde and Monoaromatic Hydrocarbons using Differential Optical Absorption Spectroscopy during Winter and Summer Intensive Periods in Seoul, Korea

Comparison of aromatic hydrocarbon measurements made by PTR-MS, DOAS and GC-FID during the MCMA 2003 Field Experiment

Direct atmospheric pressure chemical ionization-tandem mass spectrometry for the continuous real-time trace analysis of benzene, toluene, ethylbenzene, and xylenes in ambient air

Contact Info

Product

Resources

About