| 摘要 |
A discharge ionization current detector using a low-frequency barrier discharge is provided to improve the linearity of detection sensitivity with respect to a sample introduction amount. From a lower end of a lower gas passage 10 connected to a lower end of an upper gas passage 4, a dilution gas is supplied upward against a downward flow of a plasma gas. A gas discharge passage 15 for discharging a plasma gas, the dilution gas and a sample gas is arranged between an ion-collecting electrode 11 and a bias voltage application electrode 12. The sample gas introduced through a capillary tube 16 is mixed with the plasma gas and the dilution gas due to a disturbed flow generated by collision of the plasma gas and the dilution gas. The sample component is efficiently ionized by light from the plasma without undergoing light-shielding effect of concentrated sample components. Furthermore, since an ion generation area is close to the electrodes 11 and 12, ions can quickly move the short distance due to the action of a direct current electric field. Therefore, the ions can reach the ion-collecting electrode 11 before their lifetime terminates. |
