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Titolo:
On-line measurements of a-pinene ozonolysis products using an atmospheric pressure chemical ionisation ion-trap mass spectrometer
Autore:
Warscheid, B; Hoffmann, T;
Indirizzi:
ISAS, D-44013 Dortmund, Germany ISAS Dortmund Germany D-44013ISAS, D-44013 Dortmund, Germany
Titolo Testata:
ATMOSPHERIC ENVIRONMENT
fascicolo: 16, volume: 35, anno: 2001,
pagine: 2927 - 2940
SICI:
1352-2310(200106)35:16<2927:OMOAOP>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
GAS-PHASE REACTIONS; VOLATILE ORGANIC-COMPOUNDS; TERPENE OXIDATION-PRODUCTS; ALPHA-PINENE; BETA-PINENE; PARTICULATE PRODUCTS; BOUNDARY-LAYER; OH RADICALS; PPTV LEVELS; PTR-MS;
Keywords:
biogenic hydrocarbon; ozone; olefin reaction; reaction mechanism; mass spectrometry;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Physical, Chemical & Earth Sciences
Citazioni:
53
Recensione:
Indirizzi per estratti:
Indirizzo: Hoffmann, T ISAS, POB 101352, D-44013 Dortmund, Germany ISAS POB 101352 Dortmund Germany D-44013 13 Dortmund, Germany
Citazione:
B. Warscheid e T. Hoffmann, "On-line measurements of a-pinene ozonolysis products using an atmospheric pressure chemical ionisation ion-trap mass spectrometer", ATMOS ENVIR, 35(16), 2001, pp. 2927-2940

Abstract

An on-line technique to investigate complex organic oxidation reactions inenvironmental chamber experiments is presented. The method is based on thedirect introduction of the chamber air into an atmospheric pressure ion source of a commercial ion-trap mass spectrometer. To demonstrate the analytical potential of the method (atmospheric pressure chemical ionisation/mass spectrometry, APCI/MS), the ozonolysis of cc-pinene was investigated in a series of experiments performed in various sized reaction chambers at atmospheric pressure and 296 K in synthetic air. Investigations were focussed on the influence of the water vapour concentration on the formation of the predominant oxidation product, pinonaldehyde, derived from the alpha -pinene/ozone reaction. Quantification of pinonaldehyde was achieved by conducting astandard addition technique. The molar yield of pinonaldehyde was found todepend strongly on the actual water vapour concentration between <1 and 80% relative humidity. Starting with an average yield of 0.23 +/- 0.05 at dryconditions, pinonaldehyde formation was approximately doubled by reaching a yield of 0.53 +/- 0.05 at a relative humidity of around 60%. Furthermore,the formation mechanism of pinonaldehyde was investigated in greater detail using isotopically labelled water. Applying on-line APCI/MS, pinonaldehyde formation under incorporation of O-18 was observed, strongly supporting the reaction of the stabilised Criegee radical with water in the gas phase as suggested by Alvarado et al. (Journal of Geophysical Research 103 (1998) 25541-25551). Furthermore, the mass spectra recorded on-line were used to perform a semi-quantitative estimation of the decomposition pathway of the primary ozonide, indicating a branching ratio of 0.35/0.65. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/06/18 alle ore 17:18:46