Pyrolysis for Thermal Analysis

4 Pyrolysis Mass Spectrometry 6.4.1 Pyrolysis for Thermal Analysis 

In this section, the technical details and operation of the EGA-IAMS system are described, together with several advantages that this system has over conventional 

2 Tengyerature-Progranuned Heating Probe for Evolved Gas Analysis (EGA) 

Vitamin C and Ion attachment mass spectrometry with a temperature-pro-grarmned direct probe allows the detection of irrtact pyrolysis products. It, therefore, offers the opportunity to monitor directly thermal byproducts on a real-time basis and potentially to detect thermally imstable products. EGA-IAMS is used to study the real-time, non-isothermal decomposition of vitamin C [30]. The results were compared with those obtained in a similar study on thermal decomposition of vitamin C using pyrolysis GC/MS. Significant differences were found between the two techniques, in terms of the nature and relative amoimts of products formed. A major difference between the two techniques was in the transportation time of the pyrolysis products out of the pyrolysis chamber (or hot zone). The time was significantly shorter in EGA-IAMS than in pyrolysis GC/MS, which reduces the occmrcnce of secondary reactions of the primary pyrolysis products. Some decomposition products formed in the EGA-IAMS system were not detected in the previous pyrolysis GC/MS study [38] and thus were detected for the first time. For instance, dehydro-L-ascorbic acid was observed as a decomposition product. This compoimd was the main degradation product detected by means of EGA-IAMS. While it is an important compoimd because it possesses some biological activity, dehydro-L-ascotbic acid is difficult to measure due to its chemical instabihty. 

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