Analysis of trace amounts of carbon dioxide, oxygen and carbon monoxide in nitrogen using dual capillary columns and a pulsed discharge helium ionisation detector

Gas mixtures of trace amounts of carbon dioxide (CO2), dioxygen (O2), and carbon monoxide (CO) in dinitrogen (N2) were separated and quantified using parallel dual capillary columns and pulsed discharge helium ionisation detection (PDHID). The detection limits (9 × 10−9 mol mol−1 for CO2, 7 × 10−9 mol mol−1 for O2 and 37 × 10−9 mol mol−1 for CO) were lower than those reported previously for similar methods. Uncertainties were calculated and results were validated by comparison of the CO and CO2 results with those obtained using conventional methods. The method was also used to analyse nitrogen, carbon dioxide and carbon monoxide in oxygen.