Application of gas chromatography to respiratory gas analysis

¹ Research Service, Wood Veterans Administration Hospital; and Departments of Physiology and Medicine, Marquette University School of Medicine, Milwaukee, Wisconsin

Analyses of respiratory gases for CO₂ and O₂ can be performed on a single sample with the Fisher model 25 gas partitioner. By modifying the instrument and adding a Wilkens gas-sampling valve and a zero-suppression selector to the system, we have been able to achieve analytical accuracy comparable to that for the Scholander micrometer gas analyzer. The zero-suppression selector was considered to be essential for achieving maximum accuracy with peak height measurements. With this system, the standard deviation for its accuracy was ±0.024 vol. % for O₂ and approximately ±0.002 vol. % for CO₂ in respiratory gas samples. Empirical equations were developed to correct for argon interference in O₂ determinations. Gas chromatography offers a unique advantage which is not shared by other instruments. It provides a single analytical technique for the simple and accurate analysis of a wide spectrum of gases useful in studies of respiratory physiology and pathology.