| 摘要 |
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. After trapping of the NMOG group, the flow direction through the column is reversed and the column temperature is increased to desorb the NMOG group which is evaluated using a detector such as a flame ionization detector (FID).
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