A simple directly combined gas chromatographic-infrared spectrometric system suitable for the identification of low molecular weight hydrocarbon-type compounds is reported. It incorporates a 30-m × 0.5-mm i.d. SCOT Silicone DC-550 column and a micro light pipe gas cell (volume 0.6 ml) fitted on a kinematic mounting into the sample compartment of a conventional ir spectrophotometer. Sensitivity is enhanced by a gas chromatographic fraction concentrator, a 10-cm × 1.0-mm i.d. 10% Silicone SE-30/Chromport A (80 to 100 mesh) column, situated upstream of the gas cell. The performance of the system is demonstrated for synthetic mixtures of C6 – C10 paraffinic, olefinic, and aromatic types of hydrocarbons. Infrared spectra can be taken at 5- to 6-min intervals at levels of 14 to 19 μg per sample component. This system has potential for application in the field of trace analysis, e.g., air pollution.
C. W. Louw and J. F. Richards, "A Simple Directly Combined Gas Chromatographic-Infrared Spectrometric System for Identification of Low Molecular Weight Hydrocarbons," Appl. Spectrosc. 29, 15-24 (1975)