I dont know about using DSC for measuring heat of adsorption (that will be interesting if it is possible!) but have you thought about using Inverse Gas Chromatography(IGC)? I dont know what shape your sample is , if it is powder, fiber or a thin film, IGC can give very interesting info about surface properties such as enthalpy of adsorption.

using DSC, the specific reaction heat (whatever exo- or endothermic reaction this might be) can typically be obtained by subtracting a porpper measured baseline and normalizing of the date by dividing the heat flow signal (in mW) with sample mass (in mg) and scanning rate in K/s - the resulting unit is J/(g*K). Integration as function of temperature of the peak area then results in the specific reaction heat in J/g. The tricky thing might be to find the propper zero level for integration. Good luck!

@Benjamin .

Thanks for the detail. but how can heat of adsorption at isothermal condition be measured? the method you are explaining is for changing temp.

Hi Syed, you're right DSC is mostla used for temperature scans, however under certain circumstances DSC can give a reasonable heat flow siganl during isothermal holding too - in detail that depends on the exact type of DSC. For instance CALVET sensor type DSCs are sometimes used in a way, that the DSC sensor ist already heated to the temperature you want to perform your isothermal measurment and than the sample is placed into the system. Sometimes even power compensated DSC are usful for isothermal measurments, check out for instance this publication:

Article Isothermal Time-Temperature-Precipitation Diagram for an Alu...

for more details on DSC types, their application and performance I suggest you this book:

Höhne, Hemminger, Flammershaim: Differential Scanning Calorimetry. second edition: Springer (2003).

cheers, Benjamin

@Benjamin

Thanks dear yess I am using power compensated DSC for this purpose.