Gas chromatography in determination of pulmonary diffusing capacity

Abstract

Measurements of pulmonary diffusing capacity (Dco) were made using gas chromatography. The standard breath-holding technic was employed with the modification of using neon instead of helium for the dilution-reference gas. The two basic columns, silica gel, and 13 x molecular sieves were arranged in series on a dual-column chromatograph. All analyses were performed isothermally between 75–85 C with a carrier gas flow rate of 50–60 ml/min. Quantitation of the gas components was made simply and accurately by peak height measurements of the deflection curves on the chromatogram. The normal values for Dco by this method fall well within the range of normals determined by standard technics. The eminent suitability of gas chromatography for the determination of diffusing capacity derives from its simplicity, accuracy, and rapidity of gas analysis and its use of very small volumes of alveolar gas. breath-holding technic; neon; silica gel; 13 x molecular sieves; isothermic analysis; peak height measurements; dual-column chromatography Submitted on September 6, 1963