Optimizing the Analysis of Volatile Organic Compounds
Optimizing the Analysis of Volatile Organic Compounds
Optimizing the Analysis of Volatile Organic Compounds
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
30<br />
Gas Chromatography & Mass<br />
Spectrometry, A Practical Guide<br />
Separation conditions<br />
for numerous compound<br />
types, derivatized and<br />
underivatized.<br />
How to interpret massspectral<br />
data, with<br />
examples.<br />
F.G. Kitson, B.S. Larsen and C.N.<br />
McEwen, Academic Press, 1996,<br />
381pp., ISBN 0-12-483385-3<br />
cat.# 20497<br />
www.restekcorp.com<br />
GC/MS Operation<br />
Mass spectrometry (MS) is <strong>the</strong> most common detection system used for VOC analysis. The<br />
MS provides unique spectral information for accurately identifying components eluting from<br />
<strong>the</strong> capillary column. As a compound exits <strong>the</strong> column it is bombarded with high-energy<br />
electrons and is broken into structurally significant charged fragments. These fragments are<br />
separated by <strong>the</strong>ir mass-to-charge ratios in <strong>the</strong> analyzer, to produce a spectral pattern (i.e.,<br />
fingerprint) unique to <strong>the</strong> compound. To confirm <strong>the</strong> identity <strong>of</strong> <strong>the</strong> compound <strong>the</strong> spectral<br />
fingerprint is matched to a library <strong>of</strong> known spectra. By knowing <strong>the</strong> spectral patterns for<br />
compounds in <strong>the</strong> target list, <strong>the</strong> appropriate masses for quantification can be chosen.<br />
For analyzing volatile compounds in environmental samples, <strong>the</strong> most common types <strong>of</strong> MS<br />
operating systems are <strong>the</strong> quadrupole system and <strong>the</strong> ion trap system.<br />
Quadrupole Operation<br />
A narrow bore (