What is the method used by gas chromatography in pulmonary testing?

Gas chromatography is a laboratory technique used to separate and analyze compounds that can be vaporized without decomposition. In the context of pulmonary function testing, this method is particularly valuable for detecting various gases present in the respiratory system, such as carbon monoxide (CO) and noble gases like neon (Ne).

The utility of gas chromatography in pulmonary testing lies in its ability to provide precise measurements of gaseous substances in exhaled breath. Carbon monoxide is a specific focus because it is often used to assess exposure to smoke or air pollutants, and its concentration in exhaled breath can provide insight into a person's smoking status or environmental exposure. Neon, while not as commonly analyzed, can serve specific research purposes in pulmonary function assessments.

The other options relate to different methods or techniques in pulmonary testing that do not directly employ gas chromatography. Measuring lung capacity, analyzing blood gases, and tracking respiratory rates involve other testing methodologies, such as spirometry or capillary blood gas analysis, which focus on different aspects of pulmonary function assessment. Thus, the focus on the simultaneous detection of gases like CO and Ne clearly aligns with the strengths of gas chromatography in respiratory studies.