A dielectric barrier discharge ionization detector capable of achieving a high signal-to-noise ratio is provided. The detector includes: a discharging section for generating plasma from argon-containing gas by electric discharge; and a charge-collecting section for ionizing a component in a sample gas by an effect of the plasma and for detecting ion current formed by the ionized component. The discharging section includes a cylindrical dielectric tube having a high-voltage electrode connected to AC power source as well as upstream-side and downstream-side ground electrodes and formed on its outer circumferential wall. A semiconductor film is formed on the inner circumferential surface of the tube. The upstream-side and downstream-side ground electrodes are respectively made longer than the initiation distances for a creeping discharge between the high-voltage electrode and a tube-line tip member as well as between the high-voltage electrode and the charge-collecting section.

A discharge ionization current detector of the present invention is used for a detector for a gas chromatograph and suitable for analyzing high-boiling components. A discharge ionization current detector 10 is mainly constituted by a plasma generating section 20 and an ion collecting section 30. Regarding the ion collecting section 30, an ion collecting electrode 31 and a bias electrode 32 are arranged, and furthermore, an insulating member made of sapphire or aluminum oxide having a purity equal to or greater than 99.5% is arranged between the ion collecting electrode 31 and the bias electrode 32.

A dielectric barrier discharge ionization detector Includes: a dielectric tube; a high-voltage electrode connected to an AC power source and circumferentially formed on the outer wall of the dielectric tube; upstream-side and downstream-side ground electrodes and circumferentially formed above and below the high-voltage electrode; a discharging section for generating electric discharge to create plasma, from a gas containing argon; and a charge-collecting section for ionizing sample-gas components by the plasma and detecting an ion current formed by the ionized components. The detector also satisfies one or both of the following conditions: the upstream-side ground electrode is longer than a creeping discharge initiation distance between a tube-line tip member at the upper end of the dielectric tube and the high-voltage electrode; or the downstream-side ground electrode is longer than a creeping discharge initiation distance between the high-voltage electrode and the charge-collecting section.

The dielectric barrier discharge ionization detector includes: a dielectric tube through which a plasma generation gas is passed; a high-voltage electrode formed on the outer wall of the dielectric tube; two ground electrodes and formed on the outer wall of the dielectric tube, with the high-voltage electrode in between; a voltage supplier for applying AC voltage between the high-voltage electrode and each ground electrode to generate electric discharge within the dielectric tube and thereby generate plasma from the plasma generation gas; and a charge-collecting section for detecting an ion current formed by ionized sample-component gas produced by the plasma. The distance between one ground electrode and the high-voltage electrode is longer than a discharge initiation distance between these two electrodes, while the distance between the other ground electrode and the high-voltage electrode is shorter than the discharge initiation distance between these two electrodes.

A dielectric barrier discharge ionization detector Includes: a dielectric tube; a high-voltage electrode connected to an AC power source and circumferentially formed on the outer wall of the dielectric tube; upstream-side and downstream-side ground electrodes and circumferentially formed above and below the high-voltage electrode; a discharging section for generating electric discharge to create plasma, from a gas containing argon; and a charge-collecting section for ionizing sample-gas components by the plasma and detecting an ion current formed by the ionized components. The detector also satisfies one or both of the following conditions: the upstream-side ground electrode is longer than a creeping discharge initiation distance between a tube-line tip member at the upper end of the dielectric tube and the high-voltage electrode; or the downstream-side ground electrode is longer than a creeping discharge initiation distance between the high-voltage electrode and the charge-collecting section.

A dielectric barrier discharge ionization detector capable of achieving a high signal-to-noise ratio is provided. The detector includes: a discharging section for generating plasma from argon-containing gas by electric discharge; and a charge-collecting section for ionizing a component in a sample gas by an effect of the plasma and for detecting ion current formed by the ionized component. The discharging section includes a cylindrical dielectric tube having a high-voltage electrode connected to AC power source as well as upstream-side and downstream-side ground electrodes and formed on its outer circumferential wall. A semiconductor film is formed on the inner circumferential surface of the tube. The upstream-side and downstream-side ground electrodes are respectively made longer than the initiation distances for a creeping discharge between the high-voltage electrode and a tube-line tip member as well as between the high-voltage electrode and the charge-collecting section.

The dielectric barrier discharge ionization detector includes: a dielectric tube through which a plasma generation gas is passed; a high-voltage electrode formed on the outer wall of the dielectric tube; two ground electrodes and formed on the outer wall of the dielectric tube, with the high-voltage electrode in between; a voltage supplier for applying AC voltage between the high-voltage electrode and each ground electrode to generate electric discharge within the dielectric tube and thereby generate plasma from the plasma generation gas; and a charge-collecting section for detecting an ion current formed by ionized sample-component gas produced by the plasma. The distance between one ground electrode and the high-voltage electrode is longer than a discharge initiation distance between these two electrodes, while the distance between the other ground electrode and the high-voltage electrode is shorter than the discharge initiation distance between these two electrodes.