An ion source including an ionization assembly, first and second electron sources, and a magnet assembly. The ionization assembly includes an ionization chamber and at least one ion lens. The ionization assembly has a primary axis defined by the direction of an ion beam exiting the ionization assembly and the ionization chamber and the at least one ion lens are arranged along the primary axis. The first electron source is aligned along the primary axis of the ionization assembly and is configured to provide an electron beam parallel to the primary axis. The second electron source is adjacent to the ionization assembly and is configured to provide an electron beam orthogonal to the primary axis. The magnet assembly includes a magnet. The magnet assembly is movable between a first position in which the magnet is aligned with the first electron source and a second position in which the magnet is aligned with the second electron source.

A mass spectrometry method comprising steps of generating an ion beam from an ion source; directing the ion beam into a collision cell; introducing into the collision cell through a gas inlet on the collision cell a charge-neutral analyte gas or reaction gas; ionizing the analyte gas or reaction gas in the collision cell by means of collisions between the analyte gas or reaction gas and the ion beam; transmitting ions from the ionized analyte gas or reaction gas from the collision cell into a mass analyzer; and mass analyzing the transmitted ions of the ionized analyte or reaction gas. The methods can be applied in isotope ratio mass spectrometry to determine the isotope abundance or isotope ratio of a reaction gas used in mass shift reactions between the gas and sample ions, to determine a corrected isotope abundance or ratio of the sample ions.

A mass spectrometer includes an ion source configured to generate reagent ions; a drift tube configured to cause sample molecules to react with the reagent ions to generate sample ions, the drift tube comprising two sets of electrodes which are identical in structure and symmetrically distributed in a direction perpendicular to a direction of ion drift, each set of electrodes comprising a plurality of curved cell electrodes which are distributed in a same plane and arranged in the direction of ion drift so that the sample ions are generated and drifted within a region between the two sets of electrodes and focused in the direction perpendicular to the direction of ion drift; a power supply device configured to apply, to each of the cell electrodes, a DC voltage changing in the direction of ion drift; and, a mass analyzer configured to perform mass analysis for the sample ions.

A mass analyzer includes two chambers for ionizing gas to form ions and/or introducing reaction gases to aid in ionization. A first chamber includes an electron to allow electron bombardment of a first gas. A second chamber receives a second gas and ions from the first chamber to allow interaction between the second gas, and the ions from the first chamber. The first and/or second gas may include analyte.

A method for preparing thin layers from liquid samples is disclosed. Such thin layers can be useful when analyzing samples with probes whose penetration length in these samples is short The method consists of squeezing a certain amount of a liquid sample between two approximately flat and parallel surfaces separated by a small distance then cooling down the liquid sample until it freezes in a way that the frozen sample adheres only to one of these two flat surfaces. Removing the non-adhered flat surface leaves the frozen sample layer with the thickness approximately equal to the initial distance between the two parallel surfaces.

Certain configurations of ionization sources are described. In some examples, an ionization source comprises an ionization block, an electron source, an electron collector, an ion repeller and at least one electrode configured to provide an electric field when a voltage is provided to the at least one electrode. Systems and methods using the ionization source are also described.

A spray area in which a large number of droplets of a liquid sample sprayed from a spray nozzle (3) is separated from the tip of a needle electrode (14) for corona discharge by a sufficiently large distance, with a grid electrode (15) facing the needle electrode (14) placed in between. Ring electrodes (16) for creating an electric field which drives primary ions that should react with the sample and generate sample-derived ions are provided within an ion chamber (10) between the grid electrode (15) and the spray area. Primary ions generated by corona discharge within the space between the needle electrode (14) and the grid electrode (15) pass through the opening of the grid electrode (15), reach the spray area under the effect of the electric field, and ionize sample components. Since the droplets are prevented from adhering to the needle electrode (14), the corona discharge is maintained in a stable state. The resultant primary ions are efficiently transported and used for the ionization of the sample. Therefore, no spike noise due to an unstable corona discharge occurs, so that a high-quality spectrum can be obtained.

An ionising apparatus for ionising a sample of gaseous fluid. The ionising apparatus comprises an ioniser configured to provide reactant ions; an ion modifier configured to modify the reactant ions, and a reaction region arranged to receive the modified reactant ions and a sample and to combine the sample with the modified reactant ions to ionise the sample for analysis by a detector configured to identify a substance of interest in the sample.

A spray area in which a large number of droplets of a liquid sample sprayed from a spray nozzle is separated from the tip of a needle electrode for corona discharge by a sufficiently large distance, with a grid electrode facing the needle electrode placed in between. Ring electrodes for creating an electric field which drives primary ions that should react with the sample and generate sample-derived ions are provided within an ion chamber between the grid electrode and the spray area. Primary ions generated by corona discharge within the space between the needle electrode and the grid electrode pass through the opening of the grid electrode, reach the spray area under the effect of the electric field, and ionize sample components. Since the droplets are prevented from adhering to the needle electrode, the corona discharge is maintained in a stable state.

The invention generally relates to systems and methods for conducting reactions and screening for reaction products.