Abstract: An analytical system for measuring the concentration of non-methane organic gases within a test sample including methane and non-methane component groups. In one version, a dual column analysis system utilizes a metal column and a porous layer open tubular (PLOT column to separate methane and non-methane organic gases (NMOG). The metal column captures non-methane compounds which are more easily thermally trapped on the metal column, generally higher molecular weight compounds and polar molecule, which prevents these compounds from contaminating the PLOT column. In another version, the system incorporates a single trap in the form of a porous layer open tubular (PLOT) column which the sample mixture is directed through and which traps the NMOG group through adsorption. The methane group passes through the trap and is vented to atmosphere or evaluated using a detector.

Abstract: Gas chromatography systems which provide for high speed separation of polar compounds of interest from samples which also include non-polar compounds. Efficient separation is achieved through the use of a tandem series connected combination of analytical columns, one of which having a polar stationary phase material and another having a non-polar stationary phase material. In two embodiments of the invention the order of the analytical columns is reversed. Fluid flow conduits, valves and vents are provided in a manner which eliminates mechanical valves in a sample stream.