 |
| Titel |
Chlorine activation by N2O5: simultaneous, in situ detection of ClNO2 and N2O5 by chemical ionization mass spectrometry |
| VerfasserIn |
J. P. Kercher, T. P. Riedel, J. A. Thornton |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 2, no. 1 ; Nr. 2, no. 1 (2009-05-26), S.193-204 |
| Datensatznummer |
250000437
|
| Publikation (Nr.) |
 copernicus.org/amt-2-193-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| We report a new method for the simultaneous in situ detection of nitryl chloride
(ClNO2) and dinitrogen pentoxide (N2O5) using chemical
ionization mass spectrometry (CIMS). The technique relies on the formation
and detection of iodide ion-molecule clusters, I(ClNO2)− and
I(N2O5)−. The novel N2O5 detection scheme is
direct. It does not suffer from high and variable chemical interferences,
which are associated with the typical method of nitrate anion detection. We
address the role of water vapor, CDC electric field strength, and instrument
zero determinations, which influence the overall sensitivity and detection
limit of this method. For both species, the method demonstrates high
sensitivity (>1 Hz/pptv), precision (~10% for 100 pptv in 1 s), and
accuracy (~20%), the latter ultimately determined by the nitrogen
dioxide (NO2) cylinder calibration standard and characterization of
inlet effects. For the typically low background signals (<10 Hz) and high
selectivity, we estimate signal-to-noise (S/N) ratios of 2 for 1 pptv in
60 s averages, but uncertainty associated with the instrumental zero
currently leads to an ultimate detection limit of ~5 pptv for both
species. We validate our approach for the simultaneous in situ measurement of
ClNO2 and N2O5 while on board the R/V Knorr as part of the
ICEALOT 2008 Field Campaign. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|