Gas chromatograph-mass spectrometer comprising an ion source, the walls of which are realized or covered with at least one layer of graphene. Thus realized, the gas chromato graph-mass spectrometer proves to be particularly suited to the analysis samples containing hydrogen in addition to the substances to be analyzed. This situation generally occurs when the mass spectrometer is coupled to a gas chromatograph that utilizes hydrogen as the carrier gas.

A method of targeted mass spectrometric analysis is provided for analyzing trace compounds at sub-ppb level compared to sample matrix. Sample is chromatographically separated at standard conditions to employ a map of target mass (M) versus retention time (RT). Small mass ions under M(RT) are rejected by RF field, and remaining ions are accumulated for pulsed injection into a multi-reflecting TOF MS, either directly from EI source, or from linear RF trap or via a heated RF only quadrupole with axial ion trapping. In combination with EI source the method provides sub femtogram sensitivity at matrices loads in microgram range.

An electron bombardment ion source assembly for use in a mass spectrometer and including an anode extending along an axis and surrounding an ionization volume. At least two filaments are each configured to thermionically emit electrons and are positioned outside the ionization volume and proximate to the anode. The at least two filaments each comprise an elliptically-shaped portion and non-elliptical portions on either end of the elliptically-shaped portion. The non-elliptically-shaped portions are configured to be mounted in a fixed position relative to the anode to maintain a constant distance between the elliptically-shaped portion and the anode. The elliptically-shaped portion extends along a plane that intersects a plane perpendicular to the axis of the anode at a non-zero angle.

Methods, devices, and systems for improving the quality of electrospray ionization mass spectrometer (ESI-MS) data are described, as are methods, devices, and systems for achieving improved correlation between chemical separation data and mass spectrometry data.

Among other things, we describe methods and apparatus for the ionization of target molecular analytes of interest, e.g., for use in mass spectrometry. In some implementations, a thin molecular stream is emitted in either single or a split mode and encounters both an electron-impact ion source and trochoidal electron monochromator placed sequentially or coincidently. The first ion source emits high-energy electrons (70 eV) to generate characteristic positively-charged mass fragment spectra while the second source emits low-energy electrons in a narrow bandwidth to generate negative molecular ions or other ions via electron capture ionization. The dual ion source may be coupled to analytical instruments such as a gas chromatograph and to any number of mass analyzers such as a polarity switching quadrupole mass analyzer or to multiple mass analyzers.

The invention relates to a novel ion source, which uses method for the production of highly charged ions in the local ion traps created by an axially symmetric electron beam in the thick magnetic lens. The highly charged ions are produced in the separate local ion traps, which are created as a sequence of the focuses (F.sub.1, F.sub.2, and F.sub.3) of the electron beam (EB) rippled in the magnetic field (B(z)). Since the most acute focus is called the main one, the ion source is classified as main magnetic focus ion source (MaMFIS/T), which can also operate in the trapping regime. The electron current density in the local ion traps can be much greater than that in the case of Brillouin flow. For the ion trap with length of about 1 mm, the average electron current density of up to the order of 100 kA/cm.sup.2 can be achieved. Thus it allows one to produce ions in any charge state for all elements of the Periodic Table. In order to extract the ions, geometry of the electron beam is changed to a relatively smooth electron beam by setting the potential of the focusing electrode (W) of the electron gun negative with respect to the potential of the cathode (C).

The invention relates to an ionization device with an ionization space formed in a container, an inlet system for supplying a gas to be ionized to the ionization space, an electron source having at least one filament for supply of an electron beam to the ionization space, and an outlet system for letting the ionized gas out of the ionization space. Electron optics having at least two electrodes are disposed between the filament and the ionization space.

Methods, devices, and systems for improving the quality of electrospray ionization mass spectrometer (ESI-MS) data are described, as are methods, devices, and systems for achieving improved correlation between chemical separation data and mass spectrometry data.

An electron impact ion source comprises: a first ionisation region comprising an aperture configured to receive first molecules into the first ionisation region, the first ionisation region being configured to receive an electron beam along a first axis to generate a first ion beam along the first axis from the first molecules; and a second, separate ionisation region comprising an inlet configured to receive second molecules into the second ionisation region, the second ionisation region configured to receive the electron beam along the first axis to generate a second ion beam along the first axis from the second molecules.

Specimen imaging systems and methods including a sample stage in a vacuum environment. The sample stage is configured to support a specimen, an electron beam generator configured to focus an electron beam on a first predetermined location on the specimen, a nanospray dispenser configured to dispense a nanospray onto a second predetermined location on the specimen, a mass spectrometer, and an extraction conduit configured to extract a plume of charged particles generated as a result of contact between the nanospray and the specimen and deliver the charged particles to the mass spectrometer. The systems and methods can create a topological and chemical map of the specimen by analyzing at least a portion of the specimen with a mass spectrometer to determine a chemical composition of the specimen at the second predetermined location and analyzing at least a portion of the specimen with the electron beam to determine a surface topology.