Pith. sign in

REVIEW 4 major objections 6 minor 44 references

Broadband Cavity-Enhanced Absorption Spectroscopy (BBCEAS) Coupled with an Interferometer for On-Band and Off-Band Detection of Glyoxal

T0 review · 4 major / 6 minor · reviewed 2026-08-12 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read Broadband cavity-enhanced absorption spectroscopy read out by a spectrograph detects gas-phase glyoxal at 10 parts per trillion in one minute, while an interferometer-and-photomultiplier readout reaches 600 parts per trillion.

desk verdict A useful instrument comparison with a genuine 10 ppt spectrograph detection limit, but the interferometer retrieval has an unresolved methylglyoxal interference that makes its concentration scale conditional. read the letter →

arxiv 2412.03586 v1 pith:R7BBQ6PU submitted 2024-11-25 physics.chem-ph physics.ins-det

Callum E. Flowerday , Ryan Thalman , Matthew C. Asplund , Jaron C. Hansen This is my paper · ORCID
classification physics.chem-phphysics.ins-det
keywords glyoxalbroadbandcavity-enhancedabsorptionspectroscopyBBCEASinterferometeron-band/off-banddetectionnitrogendioxidemethylglyoxalatmospherictracegas
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper is a proof-of-concept demonstration that a single high-finesse optical cavity can detect gas-phase glyoxal two ways: read out by a spectrograph plus CCD, or read out by a rotating bandpass interferometer plus photomultiplier tube. The spectrograph version achieves a 1 min $1\sigma$ detection limit of $2.5\times10^8$ molecules cm$^{-3}$ (10 ppt) for glyoxal, with methylglyoxal at 34 ppt and $\mathrm{NO_2}$ at 22 ppt. The interferometer version, which is cheaper and produces far less data, achieves a 2 min $1\sigma$ glyoxal detection limit of $1.5\times10^{10}$ molecules cm$^{-3}$ (600 ppt) and an $\mathrm{NO_2}$ limit of 900 ppt, with methylglyoxal below detection. The authors argue that the two-window on-band/off-band scheme is general enough to be pointed at other species with sharp absorption features. This matters because glyoxal is a marker for biogenic emissions and biomass burning, and a lower-cost field instrument would make such measurements more accessible.

What carries the argument

The load-bearing element is a 92.5 cm high-finesse cavity whose mirrors reach a reflectivity of 0.99985 at 455 nm, with the transmitted light split between two readouts. The spectrograph readout performs full spectral fitting of absorption cross-sections by nonlinear least squares. The interferometer readout uses a rotating bandpass filter, effectively a Fabry-Perot etalon, to alternate between an on-band window centered at 455.5 nm and an off-band window centered at 458 nm; a photomultiplier tube records each window's intensity. The off-band extinction is assigned entirely to $\mathrm{NO_2}$ by $\epsilon_{458} = [\mathrm{NO_2}]\,\sigma_{\mathrm{NO_2},458}$, and then the on-band equation $\epsilon_{455.5} = [\mathrm{CHOCHO}]\,\sigma_{\mathrm{CHOCHO},455.5} + [\mathrm{NO_2}]\,\sigma_{\mathrm{NO_2},455.5}$ is solved for glyoxal.

What would settle it

Flow a known concentration of pure methylglyoxal through the cavity while glyoxal is absent and $\mathrm{NO_2}$ is held at a fixed, known level, then retrieve $\mathrm{NO_2}$ from the off-band window centered at 458 nm: if the retrieved $\mathrm{NO_2}$ exceeds the known value, methylglyoxal is absorbing off-band and the two-window retrieval is biased.

Watch

Extended reading notes

Core claim

On the authors' own terms, the central discovery is that coupling a BBCEAS cavity to a rotating bandpass interferometer and photomultiplier can recover glyoxal concentrations from two spectral windows, one overlapping the glyoxal absorption band near 455.5 nm and one where glyoxal absorption is minimal near 458 nm, with the off-band window used to retrieve $\mathrm{NO_2}$ and the on-band window then solved for glyoxal. The spectrograph/CCD channel achieves a 1 min $1\sigma$ glyoxal detection limit of $2.5\times10^8$ molecules cm$^{-3}$ (10 ppt); the interferometer/PMT channel achieves a 2 min $1\sigma$ glyoxal detection limit of $1.5\times10^{10}$ molecules cm$^{-3}$ (600 ppt) and an $\mathrm{NO_2}$ limit of 900 ppt. The two-minute-averaged interferometer traces for glyoxal and $\mathrm{NO_2}$ reproduce the trends seen with the spectrograph, which the authors take as evidence that the cheaper readout can track ambient glyoxal, while methylglyoxal remained below the interferometer's detection limit.

Load-bearing premise

The retrieval rests on the assumption that at 458 nm both glyoxal and methylglyoxal have exactly zero absorption, so all measured off-band extinction is $\mathrm{NO_2}$; the paper's own discussion of methylglyoxal's influence on the 453-458 nm window and its estimate that about 1/30 of the interferometer glyoxal signal could be methylglyoxal show this assumption is not fully satisfied.

Editorial extensions

If this is right

  • A spectrograph-based BBCEAS can push 1 min glyoxal detection down to 10 ppt, placing it at or below the detection limits reported for earlier LED-CE-DOAS and BBCEAS instruments.
  • The interferometer/PMT path, with a 2 min glyoxal limit of 600 ppt and an $\mathrm{NO_2}$ limit of 900 ppt, is sufficient for ambient and biomass-burning plume measurements while avoiding the cost and data volume of a spectrograph.
  • Because the dual-window scheme subtracts extinction common to both windows, broadband absorbers such as aerosol can be treated as a direct intensity correction; the paper's simulated aerosol correction varies by less than 1% between the on-band and off-band windows.
  • Scanning more than two interferometer windows would allow low-resolution fitting of absorption cross-sections, which the authors suggest could aid species identification and reduce interferences.
  • The same on/off-band logic should transfer to other molecules with a sharp drop in absorption cross-section, such as formaldehyde, if the two windows are placed where only the target species absorbs.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If a second photomultiplier were added so the on-band and off-band windows were read simultaneously, the square-wave duty cycle would disappear and the interferometer channel's time resolution would roughly double.
  • Because the paper estimates that about 1/30 of the interferometer glyoxal signal could be methylglyoxal, real wildfire-plume measurements would need a methylglyoxal correction or an additional window to avoid a systematic glyoxal overestimate.
  • The claim that the off-band window is clean at 458 nm can be tested directly by flowing pure methylglyoxal through the cavity; a nonzero extinction there would require replacing Equation (5) with a multi-species retrieval.
  • The noise sources the authors list for the interferometer channel (photon-counter readout, F-matching, and LED photon budget) are equipment choices, so the 600 ppt limit is probably an equipment floor rather than a fundamental one.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 6 minor

Summary. The paper compares two detection schemes for broadband cavity-enhanced absorption spectroscopy (BBCEAS) of glyoxal: a spectrograph/CCD system, which spectrally fits CHOCHO, methylglyoxal, and NO2 over a broad wavelength range, and a rotating bandpass interferometer/PMT system, which alternates between an on-band (453.15–457.5 nm) and an off-band (456.5–459.95 nm) window and retrieves NO2 from the off-band extinction and CHOCHO from the on-band extinction after subtracting the NO2 contribution. The reported 1-minute 1-sigma detection limits for the spectrograph system are 10 ppt CHOCHO, 34 ppt methylglyoxal, and 22 ppt NO2; for the interferometer system the 2-minute 1-sigma detection limits are 600 ppt CHOCHO and 900 ppt NO2, with methylglyoxal below the detection limit. The authors frame the interferometer system as a proof-of-concept for a cost-effective, etalon-based on/off band detector coupled to a high-finesse cavity.

Significance. If the results hold, the paper provides a useful empirical comparison of two BBCEAS detector architectures and demonstrates that a simple rotating bandpass filter can extract glyoxal and NO2 concentrations with sub-ppb detection limits. The spectrograph/CCD detection limits are competitive with previous BBCEAS glyoxal instruments, and the interferometer approach is potentially cheaper and less data-intensive. The paper is explicitly a proof-of-concept, and the comparison of the two systems on the same gas stream is a valuable feature. The data availability statement and the use of literature absorption cross-sections are positive elements, though no analysis code is provided. The principal weaknesses are an internal inconsistency in the off-band assumption for methylglyoxal and the absence of a described detection-limit calculation, both of which affect the quantitative claims for the interferometer system.

major comments (4)
  1. [2.3.2, Eq. (5) and §2.2, §3.1.2] Equation (5) assumes that at 458 nm both CHOCHO and methylglyoxal have zero absorption, so all off-band extinction is attributed to NO2. This contradicts the paper's own statements: §2.2 says methylglyoxal 'impacts the 453–458 nm transmission window more substantially than the 457–459 nm window,' and §3.1.2 estimates that roughly 1/30 of the interferometer CHOCHO signal could be attributed to methylglyoxal. Because the off-band window (456.5–459.95 nm) overlaps the 453–458 nm region, methylglyoxal absorption at 458 nm is not negligible. This would cause Eq. (5) to overestimate NO2, and since that NO2 is substituted into Eq. (6), the CHOCHO retrieval would be biased low. The paper mentions that corrections 'can be applied' but does not show a corrected retrieval or quantify the bias. The stated 600 ppt detection limit for the interferometer system is therefore not verified in the presence of methylglyoxal. I ask the authors to either include a methylglyoxal term in Eq. (5) (using the spectrograph-derived methylglyoxal concentrations) or to demonstrate quantitatively that the interference is negligible at 458 nm for the reported experiments.
  2. [3.1.1 and 3.1.2] The detection limits are central quantitative claims, but the paper never states how they are computed. For example, the 1-minute 1-sigma detection limit of 10 ppt for CHOCHO with the spectrograph and the 2-minute 1-sigma limit of 600 ppt with the interferometer are reported without defining whether they are the standard deviation of the retrieved concentration during zero-air sampling, an Allan deviation, the 3-sigma fit residual, or some other statistic. Without this information the results are not reproducible, and it is not clear whether the reported values are limits of detection in the usual sense or merely precision metrics. Please specify the exact calculation, the number of replicates or spectra used, and whether the interferometer limit accounts for the methylglyoxal interference discussed in the previous comment.
  3. [2.3.2, Eqs. (4) and (6)] There are several ambiguities and apparent errors in the interferometer data-processing equations. Equation (4) includes a term [CHOCHO] σ_CHOCHO 485 nm, but the equation is written for 458 nm; the subscript '485 nm' appears to be a typo, and the term is dropped in Eq. (5) with the justification that CHOCHO has zero contribution at 458 nm. This is confusing. In addition, the text introducing Eq. (6) states that 'the NO2 concentration from the BBCEAS is substituted in,' which is ambiguous: it could refer to the NO2 retrieved from Eq. (5) using the interferometer's off-band data, or to the NO2 retrieved independently from the spectrograph. If the latter is intended, then the interferometer CHOCHO retrieval is not independent and the comparison in Figure 8 becomes partly circular. Please clarify the provenance of the NO2 concentration used in Eq. (6), and correct the wavelength subscripts consistently (455 nm vs. 455.5 nm).
  4. [Section 3.1.2] The paper does not provide an independent calibration or reference standard for the gas-phase glyoxal concentrations produced by the bubbler from the 40% w/w aqueous solution. The spectrograph retrievals rely entirely on literature absorption cross-sections, so the absolute concentration scale is not externally validated. This is acceptable for a proof-of-concept detection-limit study, but the inter-comparison between the two detectors in Figure 8 is then only a relative comparison. The authors should state this limitation explicitly and, if possible, quantify the expected uncertainty in the absolute concentration scale (e.g., from the purity of the commercial CHOCHO solution and the bubbler vapor pressure).
minor comments (6)
  1. [Figure 7 caption] The caption reads 'interferometer/CCD data,' but the detector is a PMT, not a CCD; this should be corrected to 'interferometer/PMT data.'
  2. [§3.1.2] The text says the CHOCHO data are 'unprocessed' but then describes rolling-boxcar and two-minute-average smoothing; please rephrase to distinguish the raw PMT trace from the smoothed concentration traces.
  3. [§3.1.2] The statement that both interferometer bandpass positions (centered near 455.5 nm and 458 nm) fall within the water-vapor absorption bands of 440–450 nm and 466–476 nm appears inconsistent: 455.5 nm is outside the first band and 458 nm is outside both bands. Please check the wavelength ranges and clarify.
  4. [Conclusions] The text contains a typo: 'CHOHCO' should be 'CHOCHO' in the sentence about compounds with sharp drops in absorption cross-sections.
  5. [Introduction] Reference [21] states a slant column density of '6.23 × 1015 molecules·cm2'; the exponent on cm should presumably be −2. Please correct.
  6. [References] Reference [1] is cited as a U.S. EPA substance registry entry for ethanedial; please confirm this is the appropriate source for the atmospheric-chemistry claim about glyoxal as a biogenic indicator, and consider citing a peer-reviewed review instead.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the detection limits are empirical, the spectral retrievals use external literature cross-sections and measured cavity parameters, and the self-citations are methodological rather than load-bearing.

full rationale

The central claims are measured detection limits for two BBCEAS configurations. The interferometer retrieval (Eqs. 4–6) is a two-wavelength differential scheme: the off-band extinction is used to constrain NO2 and the on-band extinction then yields CHOCHO; the CHOCHO concentration is not an input to its own derivation, and the NO2 substituted into Eq. (6) comes either from the same off-band channel or from the independent spectrograph channel, so there is no fitted-input-called-prediction loop. Mirror reflectivity is obtained from Rayleigh scattering of He/N2, and concentrations are retrieved by least-squares fitting to literature absorption cross-sections. The paper does contain an internal tension—Section 2.2 and Section 3.1.2 acknowledge methylglyoxal absorption in the nominally clean off-band window and water-vapor interference, while Eq. (5) assumes both are zero—but this is a bias/accuracy limitation, not a circularity, because the equations are not equivalent to their inputs by construction. Self-citations [24, 36–38, 42] support calibration, aerosol treatment, and prior instrument intercomparison; none is used to define the target quantity or forbid alternatives. Hence no significant circularity.

Assumptions & free parameters 1 free parameters · 3 assumptions · 0 invented entities

The central retrievals rest on measured mirror reflectivity, literature cross-sections, and a clean off-band assumption. No new physical entities are postulated, and no target-specific constants are fitted aside from an unspecified polynomial baseline in the spectral fit.

free parameters (1)
  • polynomial baseline in spectral fit = unspecified order and coefficients
    Equation (3) includes a polynomial added to the cross-section sum, fitted to each extinction spectrum. It can absorb broadband extinction and affect retrieved concentrations and quoted detection limits, but the order and coefficients are not stated.
assumptions (3)
  • standard math Beer-Lambert law and the cavity enhancement formula in Equation (2) hold for incoherent broadband light without mode structure.
    Invoked in Sections 2.3.1 and 2.3.2 through the superposition argument of Lehmann and Romanini (reference 33).
  • domain assumption Literature absorption cross-sections for glyoxal, methylglyoxal, NO2, and Rayleigh scattering are accurate at the operating temperature and pressure.
    Used in Equations (3) through (6) with no in-situ recalibration against an independent standard described.
  • domain assumption The bandpass filter passbands at the two rotation positions are as stated and can be represented by single central wavelengths.
    Equations (4) through (6) use cross-sections at 455.5 and 458 nm despite finite filter bandwidth and nominal on-band and off-band ranges in Section 2.3.2 that overlap.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Broadband Cavity-Enhanced Absorption Spectroscopy (BBCEAS) Coupled with an Interferometer for On-Band and Off-Band Detection of Glyoxal." pith.science (2026). https://pith.science/paper/R7BBQ6PU

@misc{pith2026241203586,
  author       = {Pith},
  title        = {Pith review of: Broadband Cavity-Enhanced Absorption Spectroscopy (BBCEAS) Coupled with an Interferometer for On-Band and Off-Band Detection of Glyoxal},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/R7BBQ6PU}},
  note         = {Machine review of arXiv:2412.03586}
}
abstract

Glyoxal CHOCHO is a trace gas in the atmosphere, often used as an indicator of biogenic emissions. It is frequently compared to formaldehyde concentrations, which serve as indicators of anthropogenic emissions, to gain insights into the characteristics of the environmental source. This study employed broadband cavity-enhanced absorption spectroscopy to detect gaseous CHOCHO, methylglyoxal, and $\mathrm{NO_2}$. Two different detection methods are compared. Spectrograph and CCD Detection: This approach involves coupling the system to a spectrograph with a charge-coupled device (CCD) detector. It achieved a 1 min 1-$\sigma$ detection limit of $2.5 \times 10^8$ molecules/cm$^3$, or 10 parts per trillion (ppt). Methylglyoxal and $\mathrm{NO_2}$ achieved 1 min 1-$\sigma$ detection limits of 34 ppt and 22 ppt, respectively. Interferometer and PMT Detection: In this method, an interferometer is used in conjunction with a photomultiplier tube (PMT) detector. It resulted in a 2 min 1-$\sigma$ detection limit of $1.5 \times 10^{10}$ molecules/cm$^3$, or 600 ppt. The $\mathrm{NO_2}$ 2 min 1-$\sigma$ detection limit was determined to be 900 ppt. Concentrations of methylglyoxal were difficult to determine using this method, as they appeared to be below the detection limit of the instrument. This study discusses the advantages and limitations of each of these detection methods.

Figures

Figures reproduced from arXiv: 2412.03586 by the authors.

Figure 1
Figure 1. Experimental setup showing the BBCEAS with the spectrograph setup (above cavity) and interferometer setup (below cavity). 2.2. Interferometer Setup Fabry–Perot etalons and other interferometers have been widely used for atmos￾pheric gas sensing due to their high spectral resolution, improved light throughput com￾pared to grating spectrographs, and field-ready compactness [34,35]. In this work, a band￾pass filter is … view at source ↗
Figure 2
Figure 2. Absorbing species’ absorption cross-sections indicate the absorption on-band and off￾band. This is used for the on-band (in black) and off-band (in blue) detection of CHOCHO (absorp￾tion cross-section shown in red) and methylglyoxal (absorption cross-section shown in green). NO2’s absorption cross-section is shown in brown. 2.3. Data Processing 2.3.1. Spectrometer Data Data collected using the spectrometer were anal… view at source ↗
Figure 3
Figure 3. On- and off-band data of the interferometer as measured by the PMT. The separation of on-band signal (453.15–457.5 nm, in black) being separated from off-band signal (456.5–459.95 nm, in blue) and transitional signal acquired while the interferometer is changing positions (in red). The interferometer data are processed similarly to the spectrograph data, with one key difference: instead of calculating an extinction … view at source ↗
Figures from the paper (4 more)
Figure 4
Figure 4. Figure 4: Reflectivity curve of the BBCEAS cavity as a function of wavelength (red). Uncertainty associated with the measured values is shown in gray [PITH_FULL_IMAGE:figures/full_fig_p007_4.png]
Figure 6
Figure 6. Figure 6: Concentration vs. spectrum number plots show data acquired from the spectrometer/CCD set-up. (A) CHOCHO concentration from the spectrograph; (B) Methylglyoxal concentration from (A) (B) (A) (B) (C) (D) [PITH_FULL_IMAGE:figures/full_fig_p008_6.png]
Figure 7
Figure 7. Figure 7: displays the unprocessed CHOCHO concentration data obtained from the PMT. The act of reading out the voltage from the photon counter onto the ADC introduced some noise into the PMT data. Moreover, the experimental setup for the interferometer added its own noise. Conse…
Figure 8
Figure 8. Figure 8: Concentration vs. spectrum number plot from the interferometer/PMT and spectro￾graph/CCD. The blue trace is the spectrograph/CCD NO2 data, and the purple trace are the interfer￾ometer/PMT NO2 data. Due to the interferometer’s ability to measure primarily at two wavelen…

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

44 extracted references · 44 canonical work pages

  1. [1]

    Ethanedial

    US Environmental Protection Agency. Ethanedial. 2023. Available online: https://cdxapps.epa.gov/oms-substance-registry- services/substance-details/24265 (accessed on 30 October 2023)

    work page 2023

  2. [2]

    Primary and secondary glyoxal formation from aromatics: Experimental evidence for the bicycloalkyl-radical pathway from benzene, toluene, and p-xylene

    Volkamer, R.; Platt, U.; Wirtz, K. Primary and secondary glyoxal formation from aromatics: Experimental evidence for the bicycloalkyl-radical pathway from benzene, toluene, and p-xylene. J. Phys. Chem. A 2001, 105, 7865–7874. [CrossRef]

    work page 2001

  3. [3]

    Isoprene forms secondary organic aerosol through cloud processing: Model simulations

    Lim, H.J.; Carlton, A.G.; Turpin, B.J. Isoprene forms secondary organic aerosol through cloud processing: Model simulations. Environ. Sci. T echnol. 2005, 39, 4441–4446. [CrossRef] [PubMed]

    work page 2005

  4. [4]

    Global budgets of atmospheric glyoxal and methylglyoxal, and implications for formation of secondary organic aerosols

    Fu, T.M.; Jacob, D.J.; Wittrock, F.; Burrows, J.P .; Vrekoussis, M.; Henze, D.K. Global budgets of atmospheric glyoxal and methylglyoxal, and implications for formation of secondary organic aerosols. J. Geophys. Res.-Atmos. 2008, 113. [CrossRef]

    work page 2008

  5. [5]

    Simultaneous global observations of glyoxal and formaldehyde from space

    Wittrock, F.; Richter, A.; Oetjen, H.; Burrows, J.P .; Kanakidou, M.; Myriokefalitakis, S.; Volkamer, R.; Beirle, S.; Platt, U.; Wagner, T. Simultaneous global observations of glyoxal and formaldehyde from space. Geophys. Res. Lett. 2006, 33. [CrossRef]

    work page 2006

  6. [6]

    Surface ozone exceedances in Melbourne, Australia are shown to be under NOx control, as demonstrated using formaldehyde: NO 2 and glyoxal:formaldehyde ratios

    Ryan, R.G.; Rhodes, S.; Tully, M.; Schofield, R. Surface ozone exceedances in Melbourne, Australia are shown to be under NOx control, as demonstrated using formaldehyde: NO 2 and glyoxal:formaldehyde ratios. Sci. T otal Environ. 2020, 749, 141460. [CrossRef] [PubMed] T oxics2024, 12, 26 12 of 13

    work page 2020

  7. [7]

    Reassessing the ratio of glyoxal to formaldehyde as an indicator of hydrocarbon precursor speciation

    Kaiser, J.; Wolfe, G.M.; Min, K.E.; Brown, S.S.; Miller, C.C.; Jacob, D.J.; deGouw, J.A.; Graus, M.; Hanisco, T.F.; Holloway, J.; et al. Reassessing the ratio of glyoxal to formaldehyde as an indicator of hydrocarbon precursor speciation. Atmos. Chem. Phys. 2015, 15, 7571–7583. [CrossRef]

    work page 2015

  8. [8]

    Identification of volatile organic compound emissions from anthropogenic and biogenic sources based on satellite observation of formaldehyde and glyoxal

    Chen, Y.J.; Liu, C.; Su, W.J.; Hu, Q.H.; Zhang, C.X.; Liu, H.R.; Yin, H. Identification of volatile organic compound emissions from anthropogenic and biogenic sources based on satellite observation of formaldehyde and glyoxal. Sci. T otal Environ. 2023, 859, 159997. [CrossRef] [PubMed]

    work page 2023

Show all 44 references
  1. [9]

    Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochem- istry

    DiGangi, J.P .; Henry, S.B.; Kammrath, A.; Boyle, E.S.; Kaser, L.; Schnitzhofer, R.; Graus, M.; Turnipseed, A.; Park, J.H.; Weber, R.J.; et al. Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochem- istry. Atmos. Chem. Phys. 2012, ...

    2012

  2. [10]

    GOME-2 observations of oxygenated VOCs: What can we learn from the ratio glyoxal to formaldehyde on a global scale? Atmos

    Vrekoussis, M.; Wittrock, F.; Richter, A.; Burrows, J.P . GOME-2 observations of oxygenated VOCs: What can we learn from the ratio glyoxal to formaldehyde on a global scale? Atmos. Chem. Phys. 2010, 10, 10145–10160. [CrossRef]

    2010

  3. [11]

    Vertical distribution and temporal evolution of formaldehyde and glyoxal derived from MAX-DOAS observations: The indicative role of VOC sources

    Hong, Q.Q.; Liu, C.; Hu, Q.H.; Zhang, Y.L.; Xing, C.Z.; Ou, J.P .; Tan, W.; Liu, H.R.; Huang, X.Q.; Wu, Z.F. Vertical distribution and temporal evolution of formaldehyde and glyoxal derived from MAX-DOAS observations: The indicative role of VOC sources. J. Environ. Sci. 2022, ...

    2022

  4. [12]

    Assessing the Ratios of Formaldehyde and Glyoxal to NO 2 as Indicators of O-3-NOx-VOC Sensitivity

    Liu, J.W.; Li, X.; Tan, Z.F.; Wang, W.J.; Yang, Y.M.; Zhu, Y.; Yang, S.D.; Song, M.D.; Chen, S.Y.; Wang, H.C.; et al. Assessing the Ratios of Formaldehyde and Glyoxal to NO 2 as Indicators of O-3-NOx-VOC Sensitivity. Environ. Sci. T echnol. 2021, 55, 10935–10945. [CrossRef] [PubMed]

    2021

  5. [13]

    Elevated levels of glyoxal and methylglyoxal at a remote mountain site in southern China: Prompt in-situ formation combined with strong regional transport

    Lv, S.J.; Gong, D.C.; Ding, Y.Z.; Lin, Y.J.; Wang, H.; Ding, H.; Wu, G.C.; He, C.Q.; Zhou, L.; Liu, S.C.; et al. Elevated levels of glyoxal and methylglyoxal at a remote mountain site in southern China: Prompt in-situ formation combined with strong regional transport. Sci. T o...

    2019

  6. [14]

    Importance of Wintertime Anthropogenic Glyoxal and Methylglyoxal Emissions in Beijing and Implications for Secondary Organic Aerosol Formation in Megacities

    Qiu, X.H.; Wang, S.X.; Ying, Q.; Duan, L.; Xing, J.; Cao, J.Y.; Wu, D.; Li, X.X.; Xing, C.Z.; Yan, X.; et al. Importance of Wintertime Anthropogenic Glyoxal and Methylglyoxal Emissions in Beijing and Implications for Secondary Organic Aerosol Formation in Megacities. Environ. ...

    2020

  7. [15]

    On-road vehicle emissions of glyoxal and methylglyoxal from tunnel tests in urban Guangzhou, China

    Zhang, Y.L.; Wang, X.M.; Wen, S.; Herrmann, H.; Yang, W.Q.; Huang, X.Y.; Zhang, Z.; Huang, Z.H.; He, Q.F.; George, C. On-road vehicle emissions of glyoxal and methylglyoxal from tunnel tests in urban Guangzhou, China. Atmos. Environ. 2016, 127, 55–60. [CrossRef]

    2016

  8. [16]

    On-road emissions of carbonyls from light-duty and heavy-duty vehicles.Environ

    Grosjean, D.; Grosjean, E.; Gertler, A.W. On-road emissions of carbonyls from light-duty and heavy-duty vehicles.Environ. Sci. T echnol.2001, 35, 45–53. [CrossRef] [PubMed]

    2001

  9. [17]

    On-road measurement of carbonyls in California light-duty vehicle emissions

    Kean, A.J.; Grosjean, E.; Grosjean, D.; Harley, R.A. On-road measurement of carbonyls in California light-duty vehicle emissions. Environ. Sci. T echnol. 2001, 35, 4198–4204. [CrossRef]

    2001

  10. [18]

    Emissions of Glyoxal and Other Carbonyl Compounds from Agricultural Biomass Burning Plumes Sampled by Aircraft

    Zarzana, K.J.; Min, K.E.; Washenfelder, R.A.; Kaiser, J.; Krawiec-Thayer, M.; Peischl, J.; Neuman, J.A.; Nowak, J.B.; Wagner, N.L.; Dube, W.P .; et al. Emissions of Glyoxal and Other Carbonyl Compounds from Agricultural Biomass Burning Plumes Sampled by Aircraft. Environ. Sci....

    2017

  11. [19]

    Primary emissions of glyoxal and methylglyoxal from laboratory measurements of open biomass burning

    Zarzana, K.J.; Selimovic, V .; Koss, A.R.; Sekimoto, K.; Coggon, M.M.; Yuan, B.; Dube, W.P .; Yokelson, R.J.; Warneke, C.; de Gouw, J.A.; et al. Primary emissions of glyoxal and methylglyoxal from laboratory measurements of open biomass burning. Atmos. Chem. Phys. 2018, 18, 15...

    2018

  12. [20]

    Speciation of gas-phase and fine particle emissions from burning of foliar fuels

    Hays, M.D.; Geron, C.D.; Linna, K.J.; Smith, N.D.; Schauer, J.J. Speciation of gas-phase and fine particle emissions from burning of foliar fuels. Environ. Sci. T echnol. 2002, 36, 2281–2295. [CrossRef]

    2002

  13. [21]

    Temporal and spatial variability of glyoxal as observed from space.Atmos

    Vrekoussis, M.; Wittrock, F.; Richter, A.; Burrows, J.P . Temporal and spatial variability of glyoxal as observed from space.Atmos. Chem. Phys. 2009, 9, 4485–4504. [CrossRef]

    2009

  14. [22]

    High winter ozone pollution from carbonyl photolysis in an oil and gas basin

    Edwards, P .M.; Brown, S.S.; Roberts, J.M.; Ahmadov, R.; Banta, R.M.; deGouw, J.A.; Dube, W.P .; Field, R.A.; Flynn, J.H.; Gilman, J.B.; et al. High winter ozone pollution from carbonyl photolysis in an oil and gas basin. Nature 2014, 514, 351–354. [CrossRef] [PubMed]

    2014

  15. [23]

    Direct emissions of particulate glyoxal and methylglyoxal from biomass burning and coal combustion.Sci

    Wang, T.; Huang, R.J.; Yang, L.; Dai, W.T.; Ni, H.Y.; Gong, Y.Q.; Guo, J.; Zhong, H.B.; Lin, C.S.; Xu, W. Direct emissions of particulate glyoxal and methylglyoxal from biomass burning and coal combustion.Sci. T otal Environ.2023, 862, 160757. [CrossRef] [PubMed]

    2023

  16. [24]

    Inherent calibration of a blue LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    Thalman, R.; Volkamer, R. Inherent calibration of a blue LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode. Atmos. Meas. T ech. 2010, 3, 1797–1814. [CrossRef]

    2010

  17. [25]

    Portable broadband cavity-enhanced spectrometer utilizing Kalman filtering: Application to real-time, in situ monitoring of glyoxal and nitrogen dioxide

    Fang, B.; Zhao, W.X.; Xu, X.Z.; Zhou, J.C.; Ma, X.; Wang, S.; Zhang, W.J.; Venables, D.S.; Chen, W.D. Portable broadband cavity-enhanced spectrometer utilizing Kalman filtering: Application to real-time, in situ monitoring of glyoxal and nitrogen dioxide. Opt. Express 2017, 25...

    2017

  18. [26]

    Measurement of glyoxal using an incoherent broadband cavity enhanced absorption spectrometer

    Washenfelder, R.A.; Langford, A.O.; Fuchs, H.; Brown, S.S. Measurement of glyoxal using an incoherent broadband cavity enhanced absorption spectrometer. Atmos. Chem. Phys. 2008, 8, 7779–7793. [CrossRef]

    2008

  19. [27]

    Broad-band cavity ring-down spectroscopy

    Ball, S.M.; Jones, R.L. Broad-band cavity ring-down spectroscopy. Chem. Rev. 2003, 103, 5239–5262. [CrossRef] [PubMed]

    2003

  20. [28]

    Fourier-transform cavity-enhanced absorption spectroscopy using an incoherent broadband light source

    Ruth, A.A.; Orphal, J.; Fiedler, S.E. Fourier-transform cavity-enhanced absorption spectroscopy using an incoherent broadband light source. Appl. Opt. 2007, 46, 3611–3616. [CrossRef]

    2007

  21. [29]

    Integrated cavity output analysis of ultra-weak absorption

    O’Keefe, A. Integrated cavity output analysis of ultra-weak absorption. Chem. Phys. Lett. 1998, 293, 331–336. [CrossRef]

    1998

  22. [30]

    Mode-locked cavity-enhanced absorption spectroscopy

    Gherman, T.; Romanini, D. Mode-locked cavity-enhanced absorption spectroscopy. Opt. Express 2002, 10, 1033–1042. [CrossRef] T oxics2024, 12, 26 13 of 13

    2002

  23. [31]

    Cavity-Enhanced Spectroscopy and Sensing ; Springer: Berlin/Heidelberg, Germany, 2014

    Gianluca Gagliardi, H.-P .L. Cavity-Enhanced Spectroscopy and Sensing ; Springer: Berlin/Heidelberg, Germany, 2014. [CrossRef]

    2014

  24. [32]

    Cavity Ring-Down Spectroscopy; Wiley: Hoboken, NJ, USA, 2009

    Giel Berden, R.E. Cavity Ring-Down Spectroscopy; Wiley: Hoboken, NJ, USA, 2009

    2009

  25. [33]

    The superposition principle and cavity ring-down spectroscopy

    Lehmann, K.K.; Romanini, D. The superposition principle and cavity ring-down spectroscopy. J. Chem. Phys. 1996, 105, 10263–10277. [CrossRef]

    1996

  26. [34]

    Quantitative imaging of volcanic SO 2 plumes using Fabry-Perot interferometer correlation spectroscopy

    Fuchs, C.; Kuhn, J.; Bobrowski, N.; Platt, U. Quantitative imaging of volcanic SO 2 plumes using Fabry-Perot interferometer correlation spectroscopy. Atmos. Meas. T ech. 2021, 14, 295–307. [CrossRef]

    2021

  27. [35]

    Mobile and high-spectral-resolution Fabry-Perot interferometer spectrographs for atmospheric remote sensing

    Kuhn, J.; Bobrowski, N.; Wagner, T.; Platt, U. Mobile and high-spectral-resolution Fabry-Perot interferometer spectrographs for atmospheric remote sensing. Atmos. Meas. T ech. 2021, 14, 7873–7892. [CrossRef]

    2021

  28. [36]

    Flowerday, C.E.; Bhardwaj, N.; Thalman, R.; Asplund, M.C.; Sevy, E.T.; Hansen, J.C. Absorption cross-sections for the 5th and 6th vibrational overtones in a series of short chained alcohols using incoherent broadband cavity enhanced-absorption spectroscopy (IBBCEAS). J. Mol. S...

    2023

  29. [37]

    Detection of Sulfur Dioxide by Broadband Cavity-Enhanced Absorption Spectroscopy (BBCEAS)

    Thalman, R.; Bhardwaj, N.; Flowerday, C.E.; Hansen, J.C. Detection of Sulfur Dioxide by Broadband Cavity-Enhanced Absorption Spectroscopy (BBCEAS). Sensors 2022, 22, 2626. [CrossRef]

    2022

  30. [38]

    Rayleigh scattering cross-section measurements of nitrogen, argon, oxygen and air

    Thalman, R.; Zarzana, K.J.; Tolbert, M.A.; Volkamer, R. Rayleigh scattering cross-section measurements of nitrogen, argon, oxygen and air. J. Quant. Spectrosc. Radiat. T ransf. 2014, 147, 171–177. [CrossRef]

    2014

  31. [39]

    High-resolution absorption cross-section of glyoxal in the UV-vis and IR spectral ranges

    Volkamer, R.; Spietz, P .; Burrows, J.; Platt, U. High-resolution absorption cross-section of glyoxal in the UV-vis and IR spectral ranges. J. Photochem. Photobiol. A Chem. 2005, 172, 35–46. [CrossRef]

    2005

  32. [40]

    The UV-visible absorption-spectrum of methylglyoxal.J

    Meller, R.; Raber, W.; Crowley, J.N.; Jenkin, M.E.; Moortgat, G.K. The UV-visible absorption-spectrum of methylglyoxal.J. Pho- tochem. Photobiol. A Chem. 1991, 62, 163–171. [CrossRef]

    1991

  33. [41]

    High-resolution Fourier transform measurement of the NO 2 visible and near-infrared absorption cross sections: Temperature and pressure effects

    Vandaele, A.C.; Hermans, C.; Fally, S.; Carleer, M.; Colin, R.; Mérienne, M.F.; Jenouvrier, A.; Coquart, B. High-resolution Fourier transform measurement of the NO 2 visible and near-infrared absorption cross sections: Temperature and pressure effects. J. Geophys. Res.-Atmos. ...

    2002

  34. [42]

    Instrument intercomparison of glyoxal, methyl glyoxal and NO2 under simulated atmospheric conditions

    Thalman, R.; Baeza-Romero, M.T.; Ball, S.M.; Borr ás, E.; Daniels, M.J.S.; Goodall, I.C.A.; Henry, S.B.; Karl, T.; Keutsch, F.N.; Kim, S.; et al. Instrument intercomparison of glyoxal, methyl glyoxal and NO2 under simulated atmospheric conditions. Atmos. Meas. T ech.2015, 8, 1...

    2015

  35. [43]

    Dual-wavelength dual-cavity spectrometer for NO2 detection in the presence of aerosol interference

    Chandran, S.; Puthukkudy, A.; Varma, R. Dual-wavelength dual-cavity spectrometer for NO2 detection in the presence of aerosol interference. Appl. Phys. B-Lasers Opt. 2017, 123, 213. [CrossRef]

    2017

  36. [44]

    Sources of Formaldehyde in Bountiful, Utah

    Bhardwaj, N.; Kelsch, A.; Eatough, D.J.; Thalman, R.; Daher, N.; Kelly, K.; Jaramillo, I.C.; Hansen, J.C. Sources of Formaldehyde in Bountiful, Utah. Atmosphere 2021, 12, 375. [CrossRef] Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publicatio...

    2021

Pith tools

Reviewed August 12, 2026 · model on record in the stance chip above.