System for detecting compounds in a gaseous sample by measuring photoionization and electron capture induced by spark excitation of helium

A gas detector for identification and quantification of sample compounds, comprising:

• (a) an elongated chamber having a chamber inlet at one end and an outlet at the other end, and a gas flow path between said inlet and outlet ends;
• (b) means for flowing helium in said chamber;
• (c) two electrodes spaced apart and located to produce current spark within said chamber and across said gas flow path and wherein spark interacts with said flowing helium thereby producing photon emissions;
• (d) means for introducing sample and sample carrier gas into said chamber at a Selected location remote from the electrodes in said chamber;
• (e) spaced detector means downstream in said chamber for measuring current generated by the ionization of said sample by said photon emission;
• means for:
• (1) identifying said sample by measuring the time at which said measured current flows following said introduction of said sample into said chamber, and
• (2) quantifying said sample by measuring the magnitude of said current change;
• and
• (g) means for optimizing said current generated by the ionization of said sample by adjusting said selectable location of said sample and sample carrier gas introduction into said chamber and by adjusting the voltage applied to said spaced detector means.

A charged particle detector comprising:

• (a) a closed chamber having a helium gas flow inlet at a first end and spaced outlet at a second end to enable helium flow therethrough;
• (b) spaced electrodes cooperating with a pulsed DC power supply responsive to DC current flow sufficient to enable an electrical spark to be formed between said electrodes, said electrodes being positioned to form a spark in helium flow into said chamber to thereby create photon emission;
• (c) spaced detector means downstream in said chamber for collection of charged particles downstream of the spark across the gap wherein the charged particles enable a current to be formed indicative of sample gas concentration in said chamber;
• (d) an inlet downstream in said chamber for controllably introducing a sample and carrier gas flow from a GC column at an selected location downstream from said spark forming electrodes so that said sample and carrier gas and said helium flow provide current for said detector means;
• and
• (h) means for optimizing said current by adjusting said selected location for sample gas and carrier gas introduction and by adjusting voltage applied to said detector means.