Towards the simultaneous detection of the low nmol/mol range of CO, CH 4 and CO 2 in nitrogen using GC-FID

The trace detection of carbon monoxide (CO), methane (CH 4 ) and carbon dioxide (CO 2 ) by gas chromatography with flame ionisation detection (GC-FID) can be enhanced by paying attention to several practical aspects of the measurement process. Choosing the appropriate column material, column conditioning, sample loop size, methaniser temperature, detector temperature, flow rate, back-pressure regulation and peak integration method can all affect the repeatability of peak areas of very small peaks. The relative effect of each of these variables is discussed in the context of achieving simultaneous detection of CO, CH 4 and CO 2 in nitrogen in the low nmol/mol range.