Yields of glyoxal and methylglyoxal from the nitrogen oxide(NOx)-air photooxidations of toluene and m- and p-xylene

Abstract. Glyoxal and methylglyoxal are key products of oxidative photochemistry in the lower troposphere. Reliable measurements of such compounds are critical for testing our understanding of volatile organic compound (VOC) processing in this region. We present a new method for obtaining sensitive, high time resolution, in situ measurements of these compounds via laser-induced phosphorescent decays. By exploiting the unique phosphorescent lifetimes for each molecule, this method achieves speciation and highsensitivity quantification of both molecules. With two different light sources at different wavelengths, the lowest 3σ limits of detection observed during calibration with this method are 11 pptv in 5 min for glyoxal and 243 pptv in 5 min for methylglyoxal. During ambient measurements of glyoxal, a 3σ limit of detection of < 4.4 pptv in 5 min was observed. Additionally, this method enables the simultaneous measurement of both glyoxal and methylglyoxal using a single, nonwavelength-tunable light source, which will allow for the development of inexpensive (∼$40 k) and turnkey instrumentation. The simplicity and affordability of this new instrumentation would enable the construction of a long-term, spatially distributed database of these two key species. This chemical map can be used to constrain or drive regional or global models as well as provide verification of satellite observations.

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“…methylvinylketone or 2-Methylprop-2-enal ), and aromatics (e.g. toluene, (m/p)-xylene (Tuazon et al, 1984)). …”

Section: S B Henry Et Al: Quantification Of Gas-phase (Methyl)glyomentioning

confidence: 99%

Quantification of gas-phase glyoxal and methylglyoxal via the Laser-Induced Phosphorescence of (methyl)GLyOxal Spectrometry (LIPGLOS) Method

2012

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“…Glyoxal is formed from the photooxidation of aromatic hydrocarbons (Tuazon et al, 1984;Bandow et al, 1985;Jang and Kamens, 2001) and is a miCorrespondence to: R. A. Washenfelder (rebecca.washenfelder@noaa.gov) nor oxidation product of isoprene (Yu et al, 1995;Carter and Atkinson, 1996) and other biogenic species (Fick et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Measurement of glyoxal using an incoherent broadband cavity enhanced absorption spectrometer

et al. 2008

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Abstract.We describe an instrument for simultaneous measurements of glyoxal (CHOCHO) and nitrogen dioxide (NO 2 ) using cavity enhanced absorption spectroscopy with a broadband light source. The output of a Xenon arc lamp is coupled into a 1 m optical cavity, and the spectrum of light exiting the cavity is recorded by a grating spectrometer with a charge-coupled device (CCD) array detector. The mirror reflectivity and effective path lengths are determined from the known Rayleigh scattering of He and dry zero air (N 2 +O 2 ). Least-squares fitting, using published reference spectra, allow the simultaneous retrieval of CHOCHO, NO 2 , O 4 , and H 2 O in the 441 to 469 nm spectral range. For a 1-min sampling time, the precision (±1σ ) on signal for measurements of CHOCHO and NO 2 is 29 pptv and 20 pptv, respectively. We directly compare measurements made with the incoherent broadband cavity enhanced absorption spectrometer with those from cavity ringdown instruments detecting CHOCHO and NO 2 at 404 and 532 nm, respectively, and find linear agreement over a wide range of concentrations. The instrument has been tested in the laboratory with both synthetic and real air samples, and the demonstrated sensitivity and specificity suggest a strong potential for field measurements of both CHOCHO and NO 2 .

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“…Studies by Bierbach et al [3] and Tuazon et al [12] showed that unsaturated 1,4-dicarbonyls undergo photoisomerization between cis-and trans-isomers; therefore, the 29.80, and 30.23 min. Five peaks were observed to represent the PFBHA derivatives of 3-hexene-2,5-dione isomers under the analytical conditions used for this work.…”

Section: Ch?mentioning

confidence: 99%

“…For start emissions, a third temporal profile was applied enabling the ratio of cold to hot starts to vary over the day [12]. Separate cold to hot profiles were applied to each trip type.…”

Section: Timementioning

confidence: 99%

Atmospheric Photochemistry Studies of Pollutant Emissions from Transportation Vehicles Operating on Alternative Fuels

Jeffries¹,

Sexton²,

Yu³

1998

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Yields of glyoxal and methylglyoxal from the nitrogen oxide(NOx)-air photooxidations of toluene and m- and p-xylene

Cited by 93 publications

References 11 publications

Quantification of gas-phase glyoxal and methylglyoxal via the Laser-Induced Phosphorescence of (methyl)GLyOxal Spectrometry (LIPGLOS) Method

Quantification of gas-phase glyoxal and methylglyoxal via the Laser-Induced Phosphorescence of (methyl)GLyOxal Spectrometry (LIPGLOS) Method

Measurement of glyoxal using an incoherent broadband cavity enhanced absorption spectrometer

Atmospheric Photochemistry Studies of Pollutant Emissions from Transportation Vehicles Operating on Alternative Fuels

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