Spectrometers as Detectors in Pyrolysis-Gas Chromatography

Mass spectrometers are used as detectors in gas chromatography offering the capability of compound quantitation and identification with exceptionally good sensitivity. For this reason, pyrolysis-gas chromatography/mass spectrometry (PY-GC/MS) is an excellent tool for polymer analysis. When a pyrolyser is used at the front end of the chromatograph, no special problems related to the GC/MS analysis are really added. 

The only role of the pyrolyser is in this case to provide the pyrolysate to the GC. 

Because of the extensive use of Py-GC/MS as a technique in analytical pyrolysis and because mass spectrometry is a rather complex subject [37,38], a more detailed discussion is required. 

GC/MS is a common analytical technique and a large amount of information is available regarding this subject [e.g. 38]. In GC/MS, the carrier gas containing the (separated) analytes from the GC is transferred to the mass spectrometer. The gas flow is commonly set between 0.1 to 3.0 mL/min. (at near atmospheric pressure). Because the mass spectrometers operate at 10 to 10 mbar, they are equipped with efficient pumps, which maintain inside the mass spectrometer a high vacuum. 

As described in Section 3.5, the electrons interact with the molecules M to eject an additional electron leaving a positively charged species that is a molecular ion of the type M (odd-electron OE )  

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