Ambient pressure ionization source using a laser with high spatial resolution

摘要

An interchangeable ion source for a spectrometer. The ion source includes an interface which mounts the ion source relative to a gas inlet of the spectrometer, a sample holder, a laser which produces a laser beam capable of ionizing the sample at ambient pressure, and an optical system. The ion source includes an equipment chassis which supports the interface, the sample holder, the laser and the optical system as a rigid unit such that the interface, the sample holder, the laser and the optical system remain in alignment upon attachment and detachment of the ion source from the spectrometer and an enclosure which embraces an atmosphere around components of the ion source. In addition, the ion source includes a circulator which circulates at least part of the atmosphere within the enclosure.

主权项

1. An interchangeable ion source for a spectrometer, comprising:
an interface which mounts the ion source relative to a gas inlet of the spectrometer, said inlet having at least one gas inlet opening with a characteristic opening diameter D and an inlet gas flow axis Z; a sample holder which positions a sample in proximity to the at least one gas inlet opening; an electric voltage supply which applies a voltage between the sample holder and the gas inlet of the spectrometer; a laser which produces a laser beam capable of generating ions from the sample at ambient pressure, said ions being collected into said at least one gas inlet; an optical system including one or more focusing elements which focus said laser beam into a spot of a characteristic spot diameter d on or within said sample; said spot diameter d being smaller than said opening diameter D of the gas inlet opening, where the ratio d/D is less than 1; said spot having a deviation δ from the inlet axis Z which is smaller than said opening diameter D such that a ratio δ/D is less than 1; an equipment chassis which supports the interface, the sample holder, the laser and the optical system as a rigid unit such that the interface, the sample holder, the laser and the optical system remain in alignment upon attachment and detachment of the ion source from the spectrometer; an enclosure which generally embraces an atmosphere around at least part of said interface, at least part of said sample holder, at least part of said optical system, at least part of said laser, and at least part of said chassis; and a circulator which circulates at least part of said atmosphere within said enclosure.