On-line pyrolysis-MS

Other techniques utilize lasers for sample evaporation/pyrolysis and excitation such as laser induced desorption (LID) or laser microprobe mass analysis (LAMMA) (see e g. [1]). Some of the sample introduction procedures in Py-MS enhance the information obtained from Py-MS by the use of time-resolved, temperature-resolved, or modulated molecular beams techniques [10]. In time-resolved procedures, the signal of the MS is recorded in time, and the continuous formation of fragments can be recorded. Temperature-resolved Py-MS allows a separation and ionization of the sample from a platinum/rhodium filament inside the ionization chamber of the mass spectrometer based on a gradual temperature increase [11]. The technique can be used either for polymer or for additives analysis. Attempts to improve selectivity in Py-MS also were done by using a membrane interface between the pyrolyzer and MS [12]. 

The ionization process that takes place in the ion source of the mass spectrometer can be carried out by standard ionization procedures such as electron impact (El), by chemical ionization (Cl), or by other special techniques (desorption ionization, etc.). In Py-MS, in addition to the decomposition of the sample by heat in the pyrolyzer, the pyrolysate may suffer fragmentations in the MS during the process of ion formation. 

The ions generated from all the fragments are detected and produce the mass spectrum. The abundance of each mass in the spectrum is the sum of the contributions of all species having charged fragments for that specific mass. This adds significant 

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