Gas or liquid chromatograph with detector employing ion-molecule reactions and ion drift

Claim 2

A method in accordance with claim 1, further comprising producing a concentrated sample containing said component from said effluent prior to reacting said reactant ions with the molecules of said component.

Claim 3

A method in accordance with claim 1, wherein the detecting step is carried out in a further chamber, wherein the secondary ions are passed from the first-mentioned chamber to said further chamber, and wherein the pressure in said further chamber is maintained at a level much less than the pressure in the first-mentioned chamber.

Claim 4

A method in accordance with claim 4, wherein said ions are subjected to mass analysis in said further chamber prior to detection.

Claim 5

A method in accordance with claim 4, wherein the detecting comprises producing electrons from said ions, multiplying said electrons and producing an output from the multiplied electrons.

Claim 6

A method in accordance with claim 1, wherein the ions in said chamber are segregated into groups in accordance with their statistical velocity, by ion gating.

Claim 7

Apparatus comprising, combination, a gas or liquid chromatograph, and a detector connected to receive a sample of the effluent of said chromatograph, said detector comprising a chamber having a pair of electrodes spaced apart therein, means for establishing a drift field between said electrodes, means for conducting a sample of effluent from said chromatograph into said chamber and sweeping it past one of said electrodes and out of said chamber, means including ionizing means adjacent to said one electrode for producing primary ions at a localized region adjacent to said one electrode and for causing said ions to produce product ions of at least one component of said effluent sample by ion-molecule reactions at a further region between said electrodes, means for maintaining the pressure in said chamber at a level sufficient to ensure that the mean Free path of ions in said chamber is much less than the dimensions of said chamber and such that said ions reach substantially constant mass-dependent statistical terminal velocity in said chamber between said electrodes, and means for detecting at least some of said product ions.

Claim 8

Apparatus in accordance with claim 8, wherein said means for producing primary ions comprises means for introducing a reactant gas into said chamber in addition to the sample of effluent from said chromatograph.

Claim 9

Apparatus in accordance with claim 8, wherein the pressure in said chamber is at least substantially atmospheric.

Claim 10

Apparatus in accordance with claim 8, said chamber having means for gating a portion of said product ions to a drift region of said chamber at which the ions separate in accordance with their mobility.

Claim 11

Apparatus in accordance with claim 11, said chamber having additional means for gating a portion of the separated ions to a detecting region.

Claim 12

Apparatus in accordance with claim 8, said means for conducting said sample comprising means for directing gas through said chamber in a direction transverse to the direction of said drift field.

Claim 13

Apparatus in accordance with claim 8, wherein said chamber has an ion-molecule reaction region followed by an ion drift region, and said apparatus comprises means for maintaining the effective reaction region small compared to the size of said drift region.

Claim 14

Apparatus in accordance with claim 8, wherein said means for detecting said ions comprises a mass analyzer.

Claim 15

Apparatus in accordance with claim 15, wherein said mass analyzer comprises a further chamber coupled to the first-recited chamber by a small aperture, and wherein said further chamber has means for reducing the pressure therein to a level at which the mean free path of ions is much longer than the mean free path in the first-recited chamber.

Claim 16

Apparatus in accordance with claim 8, wherein said means for detecting said ions comprises means for producing electrons in response to said ions, means for multiplying said electrons, and means for producing an output in accordance with the multiplied electrons.

Claim 17

Apparatus in accordance with claim 17, wherein said output producing means comprises signal averaging means.

Claim 18

Apparatus in accordance with claim 8, further comprising means for focusing said ions into a beam.

Claim 19

Apparatus in accordance with claim 8, further comprising means for introducing a nonreactive gas into a drift region of said chamber.

Claim 20

Apparatus in accordance with claim 8, further comprising means for concentrating the said component before said sample is introduced into said chamber.

Claim 21

Apparatus in accordance with claim 8, wherein said effluent is obtained from a liquid chromatograph and said sample is vaporized before it is introduced into said chamber.

Claim 22

Apparatus in accordance with claim 8, wherein said ionizing means is a continuous radioactive source and said field is a DC field.