Dear Estefania Roldan Nicolau,

the use of an inert atmosphere is to avoid additional reaction(s) with the ambiant atmosphere, such as oxygen. These side reactions will contribute positively and/or negatively to heat consumptiin/release which make the derivation of enthalpies meaningless, since these enthalpies will be a cumulative values and not neat values of a transition or a degradation. Vacuum is an option but evolution of volatiles will be kineticaly different from that under an inert blancket. Regards

I agree with Dr Bouaziz, the best if you can do TGA both in synthetic air and in argon or nitrogen. In oxygen you get information not only on thermal decomposition but you will see huge exotherms due to oxidation. It is useful if you study e.g. stabilization or flame retardance. I wonder, however, why you cannot attach nitrogen or argon to the TGA. I would expect that you have to change the reductor only which is special for oxygen/air. I think that it is more complicated to produce vacuum in the sample holder than to use nitrogen or argon.

Agree with Gyorgy , is not easy to do vacuum in the sample holder

Thank you everyone for your responses. Well I'm glad to know the vacuum idea is a bad idea. I do know I have to isolate the desiccation, pyrolysis and combustion peaks by changing temperatures ranges and atmospheres. My ideal is using, of course, an inert atmosphere, nevertheless I'm waiting for the response of the technicians to tell us if it's achievable to change the tank. The analyzer is a LINSEIS STA PT1600 , is anyone familiar with it ?

Sincere regards