Electrochemically generated standard additions for gas chromatography: case study of O and H analysis.

The method of standard additions with electrochemically generated spikes was elaborated and demonstrated on examples of O and H chromatographic analysis in standard mixtures. While oxygen portions may be generated directly in a stream of inert gas by solid-state electrolysis, a standard hydrogen-containing mixture is introduced into the electrochemical cell followed by controlled electrochemical consumption of hydrogen. In both cases the analysis characteristics are similar: the recovery is 90-120% and exhibits a slight sensitivity towards the flow rate of the analyzed oxygen-containing gas.

Electrochemical preparation of standard gas mixtures using solid-state electrolyte membrane.

A novel electrochemical method of preparation of standard gas mixtures for calibration of gas-analytical equipment with O, H and CO was elaborated. Utilization of solid state electrolyte membrane allows to perform a nearly 100%-efficient electrochemical generation or conversion of the analyte and avoid some problems typical for liquid electrolytes, such as solvent evaporation and condensation at the inner walls of the gas tubes or deviations from the Faraday's law. Analysis of uncertainties associated with the calibration procedure showed that the lowest systematic errors are achieved when the calibrant is generated during the electrolysis (i.