If a 0.2-ml blood sample with a paco2 of 40 mm hg diffuses across a membrane into the e2 electrode containing 0.3 ml of solution, the final paco2 in the blood sample will be less than 16 mm Hg.
PaCO2(initial)×Vinitial=PaCO2(final)×Vfinal
(40 mm Hg)(0.2 mL)=PaCO2(final)×(0.5 mL)
PaCO2(final)=16 mm Hg
In this example, CO2 diffuses from blood into a reaction solution, where some of the CO2 is removed as it is converted to HCO3−.
See the image given below:
