A method of identifying and/or characterising ions comprises separating analyte ions according to a first physico-chemical property (ion-mobility), selecting first ions of the analyte ions, and activating, fragmenting or reacting the first ions to produce first product ions, separating the first product ions according to the first physico-chemical property, and determining a pattern of the first product ions. The first ions are identified and/or characterised using the pattern of the first product ions.

A multipole ion guide includes a plurality of electrodes disposed about a longitudinal axis of the device so as to define an ion transmission volume for transmitting ions along a length of the device between opposite inlet and outlet ends. An electronic controller is operably connected to an RF power source and to at least some of the electrodes and is configured to apply at least an RF potential to the electrodes. During use the electrodes generate an RF-only field along a first portion of the device and an axial DC field along a second portion of the device. Ions are focused radially inward toward the longitudinal axis of the device by the RF-only field within the first portion of the device prior to and/or subsequent to experiencing the axial DC field within the second portion of the device.

Ions ejected from a collision cell are detected by a detector. An evaluation unit generates a temporary calibration curve based on an intensity of a detection signal and evaluates an ion accumulation time of the collision cell based on the temporary calibration curve. When the evaluation unit determines signal saturation, the ion accumulation time of the collision cell is reduced. When the evaluation unit determines sensitivity insufficiency, the ion accumulation time of the collision cell is increased.

A multipole ion guide includes a plurality of electrodes disposed about a longitudinal axis of the device so as to define an ion transmission volume for transmitting ions along a length of the device between opposite inlet and outlet ends. An electronic controller is operably connected to an RF power source and to at least some of the electrodes and is configured to apply at least an RF potential to the electrodes. During use the electrodes generate an RF-only field along a first portion of the device and an axial DC field along a second portion of the device. Ions are focused radially inward toward the longitudinal axis of the device by the RF-only field within the first portion of the device prior to and/or subsequent to experiencing the axial DC field within the second portion of the device.

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.

Provided is a method for mass spectrometry in which ions to be analyzed are made to come in contact with a cooling gas in a cooling section, such as an ion trap 2, configured to perform the cooling of ions, and kinetic energy is subsequently imparted to the ions so as to introduce the ions into a flight space of a multi-turn time-of-flight mass separator 30 or similar device for separating ions according to their mass-to-charge ratios. According to the present invention, when a known or estimated number of charges of an ion to be analyzed is high, the amount of supply of the cooling gas to the cooling section is set to a lower level than when the number of charges is low. This operation improves the detection sensitivity for ions having large molecular weights and high numbers of charges.

In a chromatograph mass spectrometer having a measurement unit (1) including a chromatograph is combined with a tandem mass spectrometry section capable of an MS/MS analysis, a controller (40) performs chromatograph mass spectrometry by controlling the measurement unit so as to operate the tandem mass spectrometry section to cyclically perform analysis cycles, where each of the analysis cycles includes a first mass spectrometric analysis in which a measurement of ions is performed over a predetermined m/z range and an MS/MS analysis by DIA in which ions included within each of a plurality of windows formed by dividing the m/z range are designated as a precursor ion. A window selector (42, 43) selects, during an execution of an analysis cycle, a window among the plurality of windows for an MS/MS analysis by DDA which is irregularly performed in an ongoing analysis cycle, based on intensity information obtained for each of the plurality of windows from an MS/MS spectrum acquired by the MS/MS analysis by DIA. A precursor-ion determiner (44) determines a precursor ion corresponding to the window selected by the window selector in a mass spectrum acquired by the first mass spectrometric analysis in the ongoing analysis cycle, based on peak information included within the m/z range of the window. A data-dependent-acquisition condition setter (45) informs the controller of the precursor ion determined by the precursor-ion determiner, as the precursor ion for the MS/MS analysis by DDA which is irregularly performed in the ongoing analysis cycle.

Methods are described for measuring the amount of C peptide in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying C peptide in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques.

A mass spectrometer includes: a target compound input receiving section for receiving an input of one or more target compounds; a measurement execution section for reading MRM measurement conditions, including a plurality of MRM transitions, respectively corresponding to the one or more target compounds from a storage section, and measuring the sample under the MRM measurement conditions; a measured multi-MRM spectrum creation section for creating a measured multi-MRM spectrum indicating an intensity of product ions as a mass peak on a graph having mass-to-charge ratios of the product ions on one axis, the intensity of the product ions acquired by measuring the sample; and a similarity degree calculation section for obtaining for each of the target compounds, a degree of similarity between standard multi-MRM spectrum stored in the storage section and the measured multi-MRM spectrum.

Apparatus is provided and an IDA method is modified to detect and separately dissociate alkali-metal adducts of a compound. An ion source device ionizes one or more compounds of a sample, producing an ion beam. A mass filter selects a mass range of precursor ions from the ion beam, a mass analyzer measures intensities and m/z values of the precursor ions, and one or more of the precursor ions are selected for a peak list. For each pair of precursor ions of the peak list, if an m/z difference between the pair corresponds to an m/z difference between an alkali metal ion and another alkali metal ion or a proton, an ExD device is used to dissociate one precursor ion or both precursor ions of the pair using the processor. A CID device is used to dissociate all other precursor ions of the peak list.