Instrument for measuring non-methane organic gases in gas samples

An analysis system for a gaseous sample, the system providing a measurement of the concentration of said non-methane organic gases group and the concentration of said methane gases group, said system comprising:

• means for providing a source of a gaseous sample including a non-methane organic gases group which excludes methane and a methane gases group including methane;
• a metal capillary tube trap for trapping a first portion of the non-methane organic gases group of the gaseous sample and passing a remainder of the gaseous sample including the methane gases group and a remainder portion of the non-methane organic gases group;
• a porous layer open tubular trap arranged downstream of said metal capillary tube trap for receiving the passed remainder of the gaseous sample, trapping the remainder portion of the non-methane organic gases group and passing the methane gases group;
• temperature control means for selectively controlling the temperature of said metal capillary tube trap and said porous layer open tubular trap, said temperature control means causing said metal capillary tube trap to thermally trap said first portion of the non-methane organic gases group by adsorption at a first trapping temperature during an adsorption phase and desorbs said first portion of the non-methane organic gases group at an elevated first desorption temperature during a desorption phase, and causing said porous layer open tubular trap to thermally trap said remainder portion of the non-methane organic gases by adsorption at a second trapping temperature during said adsorption phase and desorbs said trapped remainder portion of the non-methane organic gases group at an elevated second desorption temperature during said desorption phase;
• fluid circuit means for causing the gaseous sample to flow through said metal capillary tube trap and second porous layer open tubular trap in a first direction during said adsorption phase and thereafter causing the desorbed first portion of the non-methane organic gases group to flow in a second opposite direction through said metal capillary tube trap during said desorption phase and causing the desorbed remainder portion of the non-methane organic gases group to flow in the first direction through said porous layer open tubular trap during said desorption phase;
• first detector means operably connected to said metal capillary tube trap for measuring a concentration of said first portion of the non-methane organic gases group flowing in the second direction after said first portion of the non-methane organic gases group is desorbed from said metal capillary tube trap;
• and
• second detector means operably connected to said porous layer open tubular trap for measuring a concentration of the methane gases group passed through said porous layer open tubular column and a concentration of said remainder portion of the non-methane organic gases group desorbed from said porous layer open tubular trap.