|
Titel |
An aircraft-borne chemical ionization – ion trap mass spectrometer (CI-ITMS) for fast PAN and PPN measurements |
VerfasserIn |
A. Roiger, H. Aufmhoff, P. Stock, F. Arnold, H. Schlager |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1867-1381
|
Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 4, no. 2 ; Nr. 4, no. 2 (2011-02-04), S.173-188 |
Datensatznummer |
250001669
|
Publikation (Nr.) |
copernicus.org/amt-4-173-2011.pdf |
|
|
|
Zusammenfassung |
An airborne chemical ionization ion trap mass spectrometer instrument (CI-ITMS) has been
developed for tropospheric and stratospheric fast in-situ measurements of PAN (peroxyacetyl
nitrate) and PPN (peroxypropionyl nitrate). The first scientific deployment of the FASTPEX
instrument (FASTPEX = Fast Measurement of Peroxyacyl nitrates)
took place in the Arctic during 18 missions aboard the DLR research aircraft Falcon, within
the framework of the POLARCAT-GRACE campaign in the summer of 2008. The FASTPEX instrument
is described and characteristic properties of the employed ion trap mass spectrometer are
discussed. Atmospheric data obtained at altitudes of up to ~12 km are presented,
from the boundary layer to the lowermost stratosphere. Data were sampled with a time
resolution of 2 s and a 2σ detection limit of 25 pmol mol−1. An isotopically
labelled standard was used for a permanent on-line calibration. For this reason the accuracy
of the PAN measurements is better than ±10% for mixing ratios greater than
200 pmol mol−1. PAN mixing ratios in the summer Arctic troposphere were in the order
of a few hundred pmol mol−1 and generally correlated well with CO. In the Arctic
boundary layer and lowermost stratosphere smaller PAN mixing ratios were observed due to
a combination of missing local sources of PAN precursor gases and efficient removal
processes (thermolysis/photolysis). PPN, the second most abundant PAN homologue, was
measured simultaneously. Observed PPN/PAN ratios range between ~0.03 and 0.3. |
|
|
Teil von |
|
|
|
|
|
|