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Hello,

I would like to analyze very basic aqueous solutions (pH=13) containing NaHCO3 in GC.
I would like to proportion Inorganic Carbon presents in my solutions. In fact I would like to determine the biodeterioration of organic compounds and I would like to proportion Total Inorganic Carbon rejected in closed vials. According to a protocol which I have, at the end of the reaction he must add sodium hydroxide concentrated to solubilize CO2 present in gas phase (very high pH, approximately 13). I would like to analysis the aqueous solutions obtained by GC.
Could you please help me?

Lolo the hero

Hi Lolo,

I'm not sure I fully understand what you want to do here.
If the CO2 is produced by biodegradation by e.g. bacteria in a reactor of some sort, the CO2 concentration may be determined by directly injecting a sample of the gas (headspace) in the reactor. i.e. Total ORGANIC carbon. If you add NaOH, the CO2 would then become sequestered as INORGANIC NaHCO3, which is thermally stable to very high temperatures and not amenable to GC analysis. However the HCO3 thus produced may be determined by ion chromatography (LC). At pH 13 a polymeric ion exchange column would be required.

Sean

That's exactly what I wanted to know! Thank you Sean!

Lolo the hero