Laboratory investigation of the catalytic reduction technique for measurement of atmospheric NO<sub><i>y</i></sub>

Kliner, Dahv A. V.; Daube, Bruce C.; Burley, Joel D.; Wofsy, Steven C.

doi:10.1029/96jd03816

Cited by 58 publications

(66 citation statements)

References 61 publications

(18 reference statements)

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“…They found an almost full conversion of HCN and a partial conversion (∼40 to 65 %) of CH 3 CN at 300 • C. In the TRANC with the additional 870 • C unit we expect a full conversion of all organic N r compounds. In Kliner et al (1997) and also in a similar study by Fahey et al (1985), N 2 O conversion was found to be negligible. In our tests, we performed an in-field comparison between the sum of individually measured NO, NO 2 , NH 3 , HNO 3 , HONO, NH + 4 , NO − 3 by commercially available systems and the N r concentration by TRANC-CLD.…”

Section: Discussionsupporting

confidence: 55%

“…McCalley and Sparks also found a 100 % transformation for HONO, however only 78 to 99 % for NO y (PAN, alkyl nitrate, HNO 3 and other forms of NO y ). Kliner et al (1997) also used a Au catalyst to convert NO y compounds to NO and discovered a gas-phase process that contributes to a more readily conversion of HNO 3 than e.g. NO 2 .…”

Section: Discussionmentioning

confidence: 99%

“…The calibrator mixed the desired gas concentration by dilution of the cylinder standard with zero air. Potential loss of NO in the TRANC converter, particularly with respect to the usage of a Pt-gauze catalyst (see Kliner et al, 1997) could be excluded as no significant reduction of NO concentration was found when adding NO calibration gas upstream and downstream of the TRANC. We used gas concentrations of 6, 10, 20, and 50 ppb NO as well as pure air to calibrate the TRANC-CLD system.…”

Section: General Calibration and No 2 Conversionmentioning

confidence: 99%

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TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

Marx¹,

Brümmer

Ammann

et al. 2012

Atmos. Meas. Tech.

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Abstract. The input and loss of plant available nitrogen (reactive nitrogen: N r ) from/to the atmosphere can be an important factor for the productivity of ecosystems and thus for its carbon and greenhouse gas exchange. We present a novel converter for reactive nitrogen (TRANC: Total Reactive Atmospheric Nitrogen Converter), which offers the opportunity to quantify the sum of all airborne reactive nitrogen compounds ( N r ) in high time resolution. The basic concept of the TRANC is the full conversion of all N r to nitrogen monoxide (NO) within two reaction steps. Initially, reduced N r compounds are being oxidised, and oxidised N r compounds are thermally converted to lower oxidation states. Particulate N r is being sublimated and oxidised or reduced afterwards. In a second step, remaining higher nitrogen oxides or those generated in the first step are catalytically converted to NO with carbon monoxide used as reduction gas. The converter is combined with a fast response chemiluminescence detector (CLD) for NO analysis and its performance was tested for the most relevant gaseous and particulate N r species under both laboratory and field conditions. Recovery rates during laboratory tests for NH 3 and NO 2 were found to be 95 and 99 %, respectively, and 97 % when the two gases were combined. In-field longterm stability over an 11-month period was approved by a value of 91 % for NO 2 . Effective conversion was also found for ammonium and nitrate containing particles. The recovery rate of total ambient N r was tested against the sum of individual measurements of NH 3 , HNO 3 , HONO, NH + 4 , NO − 3 , and NO x using a combination of different well-established devices. The results show that the TRANC-CLD system precisely captures fluctuations in N r concentrations and also matches the sum of all individual N r compounds measured by the different single techniques. The TRANC features a specific design with very short distance between the sample air inlet and the place where the thermal and catalytic conversions to NO occur. This assures a short residence time of the sample air inside the instrument, and minimises wall sorption problems of water soluble compounds. The fast response time (e-folding times of 0.30 to 0.35 s were found during concentration step changes) and high accuracy in capturing the dominant N r species enables the converter to be used in an eddy covariance setup. Although a source attribution of specific N r compounds is not possible, the TRANC is a new reliable tool for permanent measurements of the net N r flux between ecosystem and atmosphere at a relatively low maintenance and reasonable cost level allowing for diurnal, seasonal and annual investigations.

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Section: Discussionsupporting

confidence: 55%

Section: Discussionmentioning

confidence: 99%

Section: General Calibration and No 2 Conversionmentioning

confidence: 99%

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TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

Marx¹,

Brümmer

Ammann

et al. 2012

Atmos. Meas. Tech.

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“…[75][76][77] Kinetics modeling, which includes the known secondary chemistry of oxides of nitrogen (ESI Table S-1), was also used to determine the NO 2 enhancement for each NaCl : NaNO 3 ratio. The solid lines in Fig.…”

Section: This Journal Is C the Owner Societies 2008mentioning

confidence: 99%

Enhanced surface photochemistry in chloride–nitrate ion mixtures

Wingen

Moskun

Johnson

et al. 2008

Phys. Chem. Chem. Phys.

116

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Heterogeneous reactions of sea salt aerosol with various oxides of nitrogen lead to replacement of chloride ion by nitrate ion. Studies of the photochemistry of a model system were carried out using deliquesced mixtures of NaCl and NaNO 3 on a Teflon s substrate. Varying molar ratios of NaCl to NaNO 3 (1 : 9 Cl À : NO 3 À , 1 : 1 Cl À : NO 3 À , 3 : 1 Cl À : NO 3 À , 9 : 1 Cl À : NO 3 À) and NaNO 3 at the same total concentration were irradiated in air at 299 AE 3 K and at a relative humidity of 75 AE 8% using broadband UVB light (270-380 nm). Gaseous NO 2 production was measured as a function of time using a chemiluminescence NO y detector. Surprisingly, an enhanced yield of NO 2 was observed as the chloride to nitrate ratio increased. Molecular dynamics (MD) simulations show that as the Cl À : NO 3 À ratio increases, the nitrate ions are drawn closer to the interface due to the existence of a double layer of interfacial Cl À and subsurface Na + . This leads to a decreased solvent cage effect when the nitrate ion photodissociates to NO 2 +O À , increasing the effective quantum yield and hence the production of gaseous NO 2 . The implications of enhanced NO 2 and likely OH production as sea salt aerosols become processed in the atmosphere are discussed.

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“…Accurate measurement requires a sampling method that rapidly and efficiently transmits the various NOy constituent species to the instrument. The present NOy measurements utilize heated catalytic converters to reduce constituent species to NO, which is then detected [Fahey et al, 1985' Nunnermacker, 1990Kliner et al, 1997]. Upstream of the converter, an inlet into which reductant and calibration gases can be added to the ambient sample is typically used, and it is the inlet that contributes most to NOy sampling uncertainties.…”

Section: Measurements Of Total Reactive Oxidized Nitrogen (Noy)mentioning

confidence: 99%

Design and initial characterization of an inlet for gas‐phase NO_y measurements from aircraft

Ryerson¹,

Huey²,

Knapp³

et al. 1999

J. Geophys. Res.

127

110

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Abstract. An understanding of gas-phase HNO3 transmission through an inlet is necessary to evaluate the quality of NOy measurements from an aircraft platform. A simple, inexpensive, low-volume Teflon inlet is described and its suitability as an aircraft inlet for gas-phase NOy is assessed. Aerosol transmission is not characterized, but inlet design and orientation probably discriminates against the majority of aerosol by mass. Laboratory data, in-flight HNO3 standard addition calibrations, and ambient NOy measurements from the 1997 North Atlantic Regional Experiment aircraft mission are used to characterize inlet transmission efficiencies and time constants. Laboratory tests show high transmission efficiencies for HNO3 which are relatively independent of ambient temperature and humidity. In-flight standard addition calibrations were carried out at ambient temperatures ranging from -20 ø to +8øC and relative humidities from 3% to 71%. These data suggest that nearly all the sampled air contacts an inlet surface, with 90% of added HNO3 being transmitted in -1.5 s. Ambient data are presented to demonstrate negligible hysteresis in 1-Hz NOy measurements, relative to variability observed in ozone data, from an air mass where HNO3 is expected to be a large fraction of the total NOy. Power spectra of ambient NOy (at temperatures from -35 ø to +35øC and relative humidities from 3% to 100%) and ozone measurements suggest an effective NOy instrument time constant of-2 s.

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Laboratory investigation of the catalytic reduction technique for measurement of atmospheric NO_y

Cited by 58 publications

References 61 publications

TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

Enhanced surface photochemistry in chloride–nitrate ion mixtures

Design and initial characterization of an inlet for gas‐phase NO_y measurements from aircraft

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Laboratory investigation of the catalytic reduction technique for measurement of atmospheric NOy

Cited by 58 publications

References 61 publications

TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

Enhanced surface photochemistry in chloride–nitrate ion mixtures

Design and initial characterization of an inlet for gas‐phase NOy measurements from aircraft

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Laboratory investigation of the catalytic reduction technique for measurement of atmospheric NO_y

Design and initial characterization of an inlet for gas‐phase NO_y measurements from aircraft