Osmometry of CO2 in gas samples.

ABSTRACT

Measurement of solute concentrations in biologic fluids by an osmometric technique has been described previously. Here, we describe an osmometric technique for measuring CO2 in gas samples. A solution of NaOH is injected into a graduated syringe containing the gas sample and CO2 is trapped in the reaction 2NaOH + CO2 leads to Na2CO3 + H2O. The decrease in osmolality of the NaOH solution allows estimation of pCO2 in the original gas sample.