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.

An ion optical arrangement (1) for use in a mass spectrometer comprises electrodes (11, 12, 14) comprising a multipole arrangement defining an ion optical axis, and a voltage source for providing voltages to the electrodes to produce electric fields. The ion optical arrangement is configured for producing a radio frequency electric focusing field for focusing ions on the ion optical axis. The radio frequency electric focusing field has a varying frequency so as to reduce any mass dependence of ion trajectories through the ion optical arrangement. The ion optical arrangement may further be configured for producing a static electric field in response to a DC bias voltage applied to the multipole arrangement. A superimposed varying electric field may be produced by superimposing an AC voltage upon the DC bias voltage.

An ion optical arrangement (1) for use in a mass spectrometer comprises electrodes (11, 12, 14) comprising a multipole arrangement defining an ion optical axis, and a voltage source for providing voltages to the electrodes to produce electric fields. The ion optical arrangement is configured for producing a radio frequency electric focusing field for focusing ions on the ion optical axis. The radio frequency electric focusing field has a varying frequency so as to reduce any mass dependence of ion trajectories through the ion optical arrangement. The ion optical arrangement may further he configured for producing a static electric field in response to a DC bias voltage applied to the multipole arrangement. A superimposed varying electric field may be produced by superimposing an AC voltage upon the DC bias voltage.

Certain embodiments described herein are directed to methods and systems of detecting two or more analytes present in a single system such as a nanoparticle or nanostructure. In some examples, the methods and systems can estimate data gaps and fit intensity curves to obtained detection values so the amount of the two or more analytes present in the single system can be quantified.

An ion optical arrangement (1) for use in a mass spectrometer comprises electrodes (11, 12, 14) comprising a multipole arrangement defining an ion optical axis, and a voltage source for providing voltages to the electrodes to produce electric fields. The ion optical arrangement is configured for producing a radio frequency electric focusing field for focusing ions on the ion optical axis. The radio frequency electric focusing field has a varying frequency so as to reduce any mass dependence of ion trajectories through the ion optical arrangement. The ion optical arrangement may further be configured for producing a static electric field in response to a DC bias voltage applied to the multipole arrangement. A superimposed varying electric field may be produced by superimposing an AC voltage upon the DC bias voltage.

An ion optical arrangement (1) for use in a mass spectrometer comprises a collision cell defining an ion optical axis along which ions may pass, electrodes comprising a set of parallel poles (11A, 11B, 11C) arranged in the collision cell, and a voltage source for providing voltages to the electrodes to produce electric fields. The ion optical arrangement is arranged for switching between a first operation mode in which the collision cell is pressurized and a second operation mode in which the collision cell is substantially evacuated. The ion optical arrangement is further arranged for producing a radio frequency electric focusing field in the first operation mode and a static electric focusing field in the second operation mode.

An ion optical arrangement (1) for use in a mass spectrometer comprises electrodes (11) defining an ion optical path, a housing (18) for accommodating the electrodes, a voltage source for providing voltages to the electrodes to produce electric fields, and a valve for allowing gas to enter and/or leave the housing. The valve comprises an electrostatic mechanism and/or a pneumatic mechanism. The electrostatic mechanism may comprise a flexible foil (30, 31) configured for covering at least one opening (16) in the ion optical arrangement when a first voltage is applied and being spaced apart from the at least one opening when a second voltage is applied. The pneumatic mechanism may comprise a Bourdon tube.

Certain embodiments described herein are directed to methods and systems of detecting two or more analytes present in a single system such as a nanoparticle or nanostructure. In some examples, the methods and systems can estimate data gaps and fit intensity curves to obtained detection values so the amount of the two or more analytes present in the single system can be quantified.

Certain configurations described herein are directed to mass spectrometer systems that can use a gas mixture to select and/or detect ions. In some instances, the gas mixture can be used in both a collision mode and in a reaction mode to provide improved detection limits using the same gas mixture.

An ion source ionizes a compound, producing precursor ions with different m/z values. A reagent source supplies charge reducing reagent. An ion guide is positioned between a mass filter and both the ion source and the reagent source. The ion guide applies an AC voltage and DC voltage to its electrodes that creates a pseudopotential to trap the precursor ions in the ion guide below a threshold m/z. This AC voltage, in turn, causes the trapped precursor ions to be charge reduced by the reagent so that m/z values of the trapped precursor ions increase to a single m/z value above the threshold m/z. The ion guide applies the DC voltage to its electrodes relative to a DC voltage applied to electrodes of the mass filter that causes the precursor ions with m/z values increased to the single m/z value to be continuously transmitted to the mass filter.