Gas chromatography has been employed in the separation of mixtures of
air, carbon dioxide, nitrous oxide and a volatile anaesthetic (halotha
ne, isoflurane or enflurane) on a single Chromosorb 101 column by temp
erature programming from room temperature. Calibration over the requir
ed range for the analysis of exhaled air, demonstrated good linearity
with a repeatability for test mixtures of about 1 %.