Determination of Carbon Dioxide in the Parts-Per-Million Range With Gas Chromatography

Abstract

Carbon dioxide has been determined at the one part-per-million level by conversion to methane with subsequent detection with an FID. The method was found to be linear over two orders of magnitude with a minimum detectable limit of 10 parts-per-billion. The catalytic conversion and flame optimization parameters for CO₂ conversion were determined. It was found that these parameters were comparable to those for CO and thus both CO₂ and CO determinations could be made with the same apparatus. Some suggestions for increasing the signal to noise ratio for the CO conversion method by at least an order of magnitude are given.