Comparison between mass spectrometry and Haldane technique in analysing CO₂ and CO₂ concentrations in air gas mixtures

Abstract

We have evaluated a mass spectrometer for use as a gas analyser in air gas mixtures. Simultaneous determinations of O₂ and CO₂ concentrations with both the mass spectrometer and the Haldane technique were done in ninety-nine different samples of expired air from ordinary laboratory experiments. The mean differences (±SD) between the two techniques for O₂ and CO₂ concentrations were 0.003% (±0.049%), and 0.001% (±0.045%) absolute values, respectively, (P>0.05 for both), r values being 0.996 for O₂ and 0.994 for CO₂. There was a drift in the apparatus, which decreases with operating time. Proper calibration is necessary for accurate readings. A cost-benefit balance is made.

Key Words:

• carbon dioxide
• Haldane technique
• mass spectrometer
• oxygen