Gas chromatography negative ion chemical ionization mass spectrometry: application to the detection of alkyl nitrates and halocarbons in the atmosphere.
J Chromatogr A
; 1201(1): 112-9, 2008 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-18586255
ABSTRACT
Alkyl nitrates and very short-lived halocarbon species are important atmospheric trace gas species that are present in the low to sub parts per trillion concentration range. This presents an analytical challenge for their detection and quantification that requires instrumentation with high sensitivity and selectivity. In this paper, we present a new in situ gas chromatograph negative ion chemical ionization mass spectrometer (GC/NICI-MS) coupled to a non-cryogen sample pre-concentration system. This instrument, with detection limits of <0.01 ppt, is capable of detecting and quantifying a large suite of alkyl nitrate and halocarbon species with high sensitivity and precision. The effects of ion source temperature and reagent gas pressure on the ionization efficiency of the NICI mode are investigated and the results are used to optimize the sensitivity. The NICI mode is compared to the more frequently used electron impact (EI) ionization and the enhancements in sensitivity are presented for all the calibrated compounds.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Carbanilidas
/
Aire
/
Cromatografía de Gases y Espectrometría de Masas
/
Nitratos
Tipo de estudio:
Diagnostic_studies
/
Evaluation_studies
Idioma:
En
Revista:
J Chromatogr A
Año:
2008
Tipo del documento:
Article
País de afiliación:
Reino Unido