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Comprehensive two‐dimensional gas chromatography/mass spectrometric analysis of pepper volatiles
Author(s) -
Cardeal Z. L.,
Gomes da Silva M. D. R.,
Marriott P. J.
Publication year - 2006
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2665
Subject(s) - chemistry , chromatography , analytical chemistry (journal) , gas chromatography , mass spectrometry , mass spectrum , elution , two dimensional gas , two dimensional chromatography , flame ionization detector , resolution (logic) , artificial intelligence , computer science
The headspace compositions of 13 pepper and peppercorn samples of different species, colloquially also referred to as pepper, were analyzed, and more than 300 compounds were tentatively characterized by means of comprehensive two‐dimensional gas chromatography in tandem with flame ionization detection, quadrupole mass spectrometric detection and time‐of‐flight mass spectrometric detection (GC × GC‐FID, GC × GC/qMS and GC × GC/TOFMS, respectively). The analysis of volatile organic compounds (VOCs) was performed after solid‐phase microextraction (SPME) using a 75‐µm PDMS/DVB fibre. Fingerprint comparison between the three techniques permitted peaks to be assigned in the GC × GC‐FID experiment based on the analogous MS analysis, taking into account retention shifts arising from method variations. When using GC × GC/TOFMS, about five times more peaks were identified than in GC × GC/qMS. Retention indices for all peaks were calculated in the bi‐dimensional column set comprising of a 5% phenyl polysilphenylene‐siloxane primary column and a polyethylene glycol second column. The spectra obtained by both mass detection techniques (qMS and TOFMS) give very similar results when spectral library searching was performed. The majority of the identified compounds eluted as pure components as a result of high‐resolution GC × GC separations, which significantly reduces co‐elution, and therefore increases the likelihood that pure spectra can be obtained. The differences between TOFMS and qMS (in fast scanning mode) spectra were generally small. Whilst spectral quality and relative ion ratios across a narrow peak (e.g. w b ∼ 100–150 ms) do vary more for the fast peaks obtained in GC × GC/qMS operation, than with TOFMS, in general adequate spectral matching with the library can be achieved. Copyright © 2006 John Wiley & Sons, Ltd.