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Titel |
Measurements of hydrogen sulfide (H2S) using PTR-MS: calibration, humidity dependence, inter-comparison and results from field studies in an oil and gas production region |
VerfasserIn |
R. Li, C. Warneke, M. Graus, R. Field, F. Geiger, P. R. Veres, J. Soltis, S.-M. Li, S. M. Murphy, C. Sweeney, G. Petron, J. M. Roberts, J. de Gouw |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 10 ; Nr. 7, no. 10 (2014-10-29), S.3597-3610 |
Datensatznummer |
250115938
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Publikation (Nr.) |
copernicus.org/amt-7-3597-2014.pdf |
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Zusammenfassung |
Natural gas production is associated with emissions of several trace gases,
some of them classified as air toxics. While volatile organic compounds
(VOCs) have received much attention, hydrogen sulfide (H2S) can also be
of concern due to the known health impacts of exposure to this hazardous air
pollutant. Here, we present quantitative, fast time-response measurements of
H2S using proton-transfer-reaction mass-spectrometry (PTR-MS)
instruments. An ultra-light-weight PTR-MS (ULW-PTR-MS) in a mobile
laboratory was operated for measurements of VOCs and H2S in a gas and
oil field during the Uintah Basin Winter Ozone Study (UBWOS) 2012 campaign.
Measurements of VOCs and H2S by a PTR-MS were also made at the Horse
Pool ground site in the Uintah Basin during UBWOS 2013. The H2S
measurement by PTR-MS is strongly humidity dependent because the proton
affinity of H2S is only slightly higher than that of water. The
H2S sensitivity of PTR-MS ranged between 0.6–1.4 ncps ppbv−1 during
UBWOS 2013. We compare the humidity dependence determined in the laboratory
with in-field calibrations and determine the H2S mixing ratios for the
mobile and ground measurements. The PTR-MS measurements at Horse Pool are
evaluated by comparison with simultaneous H2S measurements using a PTR
time-of-flight MS (PTR-ToF-MS) and a Picarro cavity ring down spectroscopy
(CRDS) instrument for H2S / CH4. On average 0.6 ± 0.3 ppbv
H2S was present at Horse Pool during UBWOS 2013. The correlation
between H2S and methane enhancements suggests that the source of
H2S is associated with oil and gas extraction in the basin. Significant
H2S mixing ratios of up to 9 ppmv downwind of storage tanks were
observed during the mobile measurements. This study suggests that H2S
emissions associated with oil and gas production can lead to short-term high
levels close to point sources, and elevated background levels away from
those sources. In addition, our work has demonstrated that PTR-MS can make
reliable measurements of H2S at levels below 1 ppbv. |
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