Other techniques utilized in the analysis of Py-MS data

6 Infrared Spectroscopy (IR1 Used as a Detecting Technique for Pvroivsis. 

Infrared spectroscopy has been used in combination with different thermal experiments as a convenient tool of analysis. For example, IR-EGA (infrared evolved gas analysis) was used for obtaining information on different thermal and combustion processes [89]. A simple IR attachment where the sample can be pyrolysed close to the IR beam is available (Pyroscan/IR available from CDS Analytical). A gas stream can be controlled to flush the pyrolysate. 

Infrared (IR) spectrometers, particularly Fourier transform infrared (FTIR) instruments have also been used as detectors in gas chromatography [90] offering the capability of compound quantitation and identification similarly to MS instruments, although with lower sensitivity. When a pyrolyser is used at the front end of the chromatograph, it usually acts just as a convenient way of sample transformation/injection into the GC/FTIR. A few basic concepts related to IR instrumentation are given below. 

The IR absorption of eiectromagnetic energy is caused by the capability of specific parts of molecuies to vibrate with certain frequencies. Such a frequency (in wavenumbers) can be expressed by the relation  

The common IR spectrophotometers generate an absorption (or transmission) spectrum, which gives the variation of the IR absorption (transmission) of a sample as a function of frequency in a range (expressed in wavenumbers) between about 300 cm to 4000 cm . The IR spectrum can be used for compound identification (as a fingerprint) or for quantitation (commonly using a specific frequency). The quantitation is based on Beer s law, which shows that the absorption is proportional with the concentration of the analyte absorbing at a given frequency. 

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