The Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE): Task 3

Apel, E. C.; Calvert, Jack G.; Gilpin, T. M.; Fehsenfeld, F. C.; Parrish, D. D.; Lonneman, William A.

doi:10.1029/1999jd900793

Cited by 69 publications

(79 citation statements)

References 32 publications

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“…[10] The NCAR-NOMHICE analytical method was similar to that reported earlier in the literature [Apel et al, 1994[Apel et al, , 1999 and is only discussed briefly here. The system was a manually operated single stage preconcentration system.…”

Section: Ncar-nomhice Methodsmentioning

confidence: 59%

“…When no specific corresponding NIST standards were available, response factors were referenced to NIST SRM propane, and proportional responses with carbon number were assumed [Leveque, 1967;Ackman, 1968;Blades, 1976;Apel et al, 1995]. The calibration accuracy for the compounds quantified in this way, under the FID conditions employed, is estimated to be ±4% [Apel et al, 1995[Apel et al, , 1999.…”

Section: Ncar-nomhice Methodsmentioning

confidence: 99%

“…The primary objectives of the NOMHICE program have been discussed in previous publications by Apel et al [1994Apel et al [ , 1999 and will only be discussed briefly here. NOMHICE was designed to assess the accuracy and comparability of NMHC measurements from research groups around the globe.…”

Section: Introductionmentioning

confidence: 99%

“…Results were mixed in this study as a number of laboratories performed well while others showed a significant need for improvement. NCAR-NOMHICE participated interactively with these groups to help improve their performance and significant progress in the analysis of prepared mixtures was observed through this approach [Apel et al, 1999].…”

Section: Introductionmentioning

confidence: 99%

“…In Task 2, a more complex, gravimetrically prepared, 16-component hydrocarbon mixture (composition and mixing ratio not revealed) was distributed to participants as a challenge mixture to determine whether the analytical methods used provided suitable separation, identification, and quantification of the individual hydrocarbons present in the mixture [Apel et al, 1994]. In Task 3 [Apel et al, 1999], a complex synthetic air mixture (60 major components, again, composition and mixing ratio not revealed) was distributed to participants as a challenge mixture. Results were mixed in this study as a number of laboratories performed well while others showed a significant need for improvement.…”

Section: Introductionmentioning

confidence: 99%

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Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE): Task 4, ambient air

et al. 2003

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[1] The Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE) was designed to assess the accuracy and comparability of nonmethane hydrocarbon (NMHC) measurements from research groups around the globe. This is being accomplished by conducting a series of intercomparisons, called Tasks, of prepared mixtures or collected ambient air. This paper presents results for an ambient air challenge sample as part of the fourth NOMHICE installment (Task 4). Twenty-three laboratories participated in Task 4, and 30 overall analytical results are compared. The air sample provided a wide dynamic range of mixing ratios (parts per trillion by volume (pptv) to parts per billion by volume (ppbv)) as well as large number of compounds (>100). Coelutions of NMHCs with other volatile organic compounds (VOCs) such as oxygenated VOCs are shown to make the analysis of whole air samples more challenging than for prepared standard mixtures. Individual canisters containing the air sample were prepared and analyzed by the NOMHICE group at the National Center for Atmospheric Research (NCAR-NOMHICE), sent to participants for analysis, and reanalyzed upon return to NCAR-NOMHICE. The mixing ratio of propylene increased by 10% (14 pptv) in the canisters with time, and some of the less volatile compounds decreased in the canisters with time; however, the majority of the compounds were stable throughout the experiment. Participants were asked to identify and quantify as many compounds as possible with their analytical techniques and to submit their results to NCAR-NOMHICE scientists. Fiftyfour compounds were chosen for the intercomparison. Eight hundred eighty-three measurements were compared overall; the average of the mean ratios of the participants' results to NCAR-NOMHICE results was 1.03. The participants' results were combined and averaged for each individual NMHC measured and compared to the reference results; thirty-three of the 54 compounds agreed to within ±20% of the reference results. Individual analyses from participant laboratories were compared and ranked with respect to agreement with the reference values; the ranking was reconciled with the analytical procedures employed for each analysis. From this, recommendations were derived for preferred analytical techniques and practice. Recommendations include but are not limited to the following: (1) National Institute of Standards and Technology (NIST) standards or NIST-traceable standards should be used and, for mass spectrometric analyses, multicomponent NIST-traceable standards should be used; (2) if solid adsorbents are used for preconcentrating NMHCs, extensive tests should be performed to test for artifact formation and compound losses; and (3) for whole air sampling in canisters, subsequent analyses should be performed as soon as is reasonably possible to avoid the potential for compositional changes.

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Section: Ncar-nomhice Methodsmentioning

confidence: 59%

Section: Ncar-nomhice Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE): Task 4, ambient air

et al. 2003

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Arctic springtime observations of volatile organic compounds during the OASIS‐2009 campaign

et al. 2016

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Gas-phase volatile organic compounds (VOCs) were measured at three vertical levels between 0.6 m and 5.4 m in the Arctic boundary layer in Barrow, Alaska, for the Ocean-Atmosphere-Sea Ice-Snowpack (OASIS)-2009 field campaign during March-April 2009. C 4 -C 8 nonmethane hydrocarbons (NMHCs) and oxygenated VOCs (OVOCs), including alcohols, aldehydes, and ketones, were quantified multiple times per hour, day and night, during the campaign using in situ fast gas chromatography-mass spectrometry. Three canister samples were also collected daily and subsequently analyzed for C 2 -C 5 NMHCs. The NMHCs and aldehydes demonstrated an overall decrease in mixing ratios during the experiment, whereas acetone and 2-butanone showed increases. Calculations of time-integrated concentrations of Br atoms, ∫[Br]dt, yielded values as high as (1.34 ± 0.27) × 10 14 cm À3 s during the longest observed ozone depletion event (ODE) of the campaign and were correlated with the steady state Br calculated at the site during this time. Both chlorine and bromine chemistry contributed to the large perturbations on the production and losses of VOCs. Notably, acetaldehyde, propanal, and butanal mixing ratios dropped below the detection limit of the instrument (3 parts per trillion by volume (pptv) for acetaldehyde and propanal, 2 pptv for butanal) during several ODEs due to Br chemistry. Chemical flux calculations of OVOC production and loss are consistent with localized high Cl-atom concentrations either regionally or within a very shallow surface layer, while the deeper Arctic boundary layer provides a continuous source of precursor alkanes to maintain the OVOC mixing ratios.

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Measuring Hydrocarbons in the Atmosphere

Colbeck¹

2010

Handbook of Hydrocarbon and Lipid Microbiology

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The Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE): Task 3

Cited by 69 publications

References 32 publications

Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE): Task 4, ambient air

Nonmethane Hydrocarbon Intercomparison Experiment (NOMHICE): Task 4, ambient air

Arctic springtime observations of volatile organic compounds during the OASIS‐2009 campaign

Measuring Hydrocarbons in the Atmosphere

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