Electrochemical gas detection apparatus and method comprising a permeable membrane and an aqueous electrolyte

A method for the electrochemical detection of carbon dioxide, which comprises causing at least a portion of the carbon dioxide to pass through a permeable membrane and dissolve in an aqueous electrolyte containing a metal ion and an organic ligand to form in situ in the electrolyte an equilibrium between the dissolved carbon dioxide species, the metal ion and the ligand concentrations and measuring the varying metal ion concentration and hence calculating the corresponding carbon dioxide concentration by means of measuring a current passing between electrodes present in the electrolyte. Also a gas detection apparatus comprising a housing, a gas permeable membrane, an aqueous electrolyte inside the housing with electrodes. The concentration of the gas is determined amperometrically.