Glow discharge ion source

摘要

A mass spectrometer is disclosed comprising a glow discharge device within the initial vacuum chamber of the mass spectrometer. The glow discharge device may comprise a tubular electrode located within an isolation valve, which is provided in the vacuum chamber. Reagent vapor may be provided through the tubular electrode, which is then subsequently ionized by the glow discharge. The resulting reagent ions may be used for Electron Transfer Dissociation of analyte ions generated by an atmospheric pressure ion source. Other embodiments are contemplated wherein the ions generated by the glow discharge device may be used to reduce the charge state of analyte ions by Proton Transfer Reaction or may act as lock mass or reference ions.

主权项

1. A mass spectrometer comprising:
a vacuum chamber; an atmospheric pressure ion source for generating first ions, wherein first ions generated by said atmospheric pressure ion source are transmitted, in use, into said vacuum chamber via a sampling cone or first aperture; a glow discharge device for generating second ions, wherein second ions generated by said glow discharge device are either generated within said vacuum chamber or are transmitted into said vacuum chamber without being transmitted through said sampling cone or first aperture; and one or more dispensing devices for dispensing one or more reagents in proximity to said glow discharge device so that said one or more reagents are ionised, in use, by a glow discharge caused or generated by said glow discharge device; wherein said one or more reagents comprise one or more lock mass or calibration reagents for mass calibrating the mass spectrometer; wherein said glow discharge device is housed in a housing adjacent said vacuum chamber and wherein second ions generated by said glow discharge device pass from said housing through a second aperture into said vacuum chamber; and wherein an electric field is maintained between said housing and said vacuum chamber in order to urge reagent ions from said housing into said vacuum chamber.