| 摘要 |
PURPOSE:To increase the magnitude of an ion current, by repeatedly applying a high voltage as pulses to a needle-like electrode when making the excited nuclei of a carrier gas by corona discharge and projecting the nuclei onto a sample held at the tip of the needle-like electrode, to ionize the sample. CONSTITUTION:A carrier gas of argon or the like is introduced into a corona discharge section 1 so that the excited nuclei of the carrier gas are made by discharge between the needle-like electrode 4 and cylindrical electrode 3 of the section. A high voltage produced by superposing pulses from a pulse generator 8 on a DC voltage from a power supply 5 is repeatedly applied as pulses to a sample holding needle 2, and the excited nuclei are projected onto a sample at the tip of the needle to ionize the sample. An atmospheric-pressure ion source is thus manufactured. The ions of the sample are introduced into a quadruple- pole mass analyzer 7 through a pinhole plate 6. The sample ions stored while the pulses are not applied are thus projected off at one time to increase the magnitude of the ion current.
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