Abstract
An atmospheric-pressure chemical ionization-mass spectrometer (APCI-MS) system was modified to introduce gaseous samples as well as to humidify sheath and auxiliary gases. Solutions of single odorants in pentane were evaporated inside a vessel in a dry environment (relative humidity 0-10%) and in a human-breath-like environment (relative humidity 88-98%) and subsequently analyzed in the positive ion mode. The results indicated that using dry nitrogen as sheath and auxiliary gases led to strong fragmentation of the molecules combined with a low sensitivity of detection. Humidification of both gases not only increased sensitivity but also resulted in the protonated molecular ion as the base peak in 5 of the 6 compounds studied (ethyl butyrate, 3-methyl-3-phenyl glycidic acid ethyl ester, γ-decalactone, (E)-2-hexenal, and cinnamic aldehyde). Only hexanal, which formed a cluster (m/z 183), did not have the protonated molecular ion as base peak. It was found that the humidity of the sample itself did not have any influence on sensitivity or fragmentation.
Original language | English (US) |
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Pages (from-to) | 5389-5395 |
Number of pages | 7 |
Journal | Journal of agricultural and food chemistry |
Volume | 48 |
Issue number | 11 |
DOIs | |
State | Published - Dec 12 2000 |
Keywords
- APCI-MS
- Aroma release
- Flavor
- Humidification