Apparatus for detecting constituents in a sample and method of using the same

An apparatus for detecting constituents in a sample, said apparatus comprising:

• a casing;
• a flow path defined by the casing, wherein the flow path is configured to receive and direct a sample gas stream comprising one or more of the constituents within the casing;
• an ionization chamber in the casing, wherein the ionization chamber is in fluid communication with the flow path and configured to generate ions;
• a first drift region in the casing, wherein the first drift region is configured to receive the ions;
• a fragmentation region in the casing, wherein the fragmentation region is configured to receive the ions;
• a first ion shutter positioned between the fragmentation region and the first drift region, wherein the first ion shutter is adapted to operate for a predetermined time period;
• an electric field generator configured to generate a controllable electric field within the fragmentation region to thereby modify a selected portion of the ions;
• and
• a control system configured to regulate the first ion shutter for the predetermined time period to thereby facilitate an injection of the ions from the first drift tube into the fragmentation region.