Dear Meryem, Gas chemistry helps a lot in studying geothermal waters. As with the water-soluble constituents, geothermal gases can be divided into two major groups: (i) reactive gases like H2O, CO2, H2S, NH3, H2, CH4 and N2, which take part in chemical equilibria and can help us to estimate the temperature of geothermal parent fluid (in the reservoir) by using gas geothermometry, and (ii) inert gases like noble gases, can be used in understanding the source of gases [Geothermal Fluids, Chemistry and Exploration Techniques by Keith Nicholson, 1993]

Dear Meryem,

Hope to find you well.

I agree with Hakim Saibi, Nicholson (1993) is a good choice to get familiar with analytical methods of geothermal samples including water, gas, and isotopic samples.

But as a brief explanation about the analyzing of gas geothermal samples you can use several techniques.

• Gas chromatography method: for CH4, He, H2, N2, O2
• Wet chemical method: for H2S, CO2, determinations for ammonia, boron, silica, fluoride, mercury, arsenic and other trace gaseous constituents which dissolve in the steam condensate.
• new methods such as Laser-Based methods of CH4, CO2, NH3, and H2S

Regards,

Rahim

Meryem Redouane, you may find this of benefit

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