 |
| Titel |
Peroxyacetyl nitrate (PAN) and peroxyacetic acid (PAA) measurements by iodide chemical ionisation mass spectrometry: first analysis of results in the boreal forest and implications for the measurement of PAN fluxes |
| VerfasserIn |
G. J. Phillips, N. Pouvesle, J. Thieser, G. Schuster, R. Axinte, H. Fischer, J. Williams, J. Lelieveld  , J. N. Crowley |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 3 ; Nr. 13, no. 3 (2013-02-01), S.1129-1139 |
| Datensatznummer |
250017620
|
| Publikation (Nr.) |
 copernicus.org/acp-13-1129-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| We describe measurements of peroxyacetyl nitrate
(CH3C(O)O2NO2, PAN) and peroxyacetic acid (CH3C(O)OOH,
PAA) in the Boreal forest using iodide chemical ionization mass spectrometry
(ICIMS). The measurements were made during the Hyytiälä United
Measurement of Photochemistry and Particles – Comprehensive Organic Particle
and Environmental Chemistry (HUMPPA-COPEC-2010) measurement intensive. Mixing
ratios of PAN and PAA were determined by measuring the acetate ion signal
(CH3C(O)O−, m/z = 59) resulting from reaction of
CH3C(O)O2 (from the thermal dissociation of PAN) or CH3C(O)OOH
with iodide ions using alternatively heated and ambient temperature inlet
lines. During some periods of high temperature (~ 30 °C) and
low NOx (< 1 ppbv), PAA mixing ratios were similar to, or
exceeded those of PAN and thus contributed a significant fraction of the
total acetate signal. PAA is thus a potential interference for ICIMS
measurements of PAN, and especially eddy covariance flux measurements in
environments where the PAA flux is likely to be a significant proportion of
the (short timescale) acetate ion variability. Within the range of mixing
ratios of NOx measured during HUMPPA-COPEC, the modelled ratio of
PAA-to-PAN was found to be sensitive to temperature (through the thermal
decomposition rate of PAN) and the HO2 mixing ratio, thus providing some
constraint to estimates of photochemical activity and oxidation rates in the
Boreal environment. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|