| 摘要 |
An improved thermospray vaporizer is provided for obtaining an ion vapor from a liquid sample separated by chromatography for detection or analysis by a mass spectrometer. A thermospray vaporizer comprises a capillary tube for receiving the sample, and having a jet nozzle at one end removably affixed to the capillary tube with an aperture selectively sized for a range of sample flow rates and compositions. The jet nozzle includes a generally planar sapphire insert having a cylindrical-shaped aperture of a preselected diameter. The sapphire insert is swaged into a bass holder which has a slightly larger diameter aperture than the insert. A ferrule seals between the capillary tube and an end fitting, which is welded at one end to the outer sheath of the thermospray probe and retains and end nut at the other end to secure the holder in place. The insert is thus easily replaced by removing the end nut and the brass holder with the insert. An insert with an optimum diameter aperture may thus be selected for use with the vaporizer as a function of the presumed flow rate through the vaporizer, thereby optimizing performance.
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