Thermo Fisher Scientific (bremen) Gmbh

Thermo Fisher Scientific Gmbh

Dirk Nolting

Alexander Alekseevich Makarov

Eduard V Denisov

Jens Griep-Raming

Wilko Balschun

Jan-Peter Hauschild

Amelia Corinne Peterson

Oliver Lange

Nicolaie Eugen Damoc

Andreas Kuehn

Konstantin Aizikov

Martin Zeller

Eugen Damoc

Trapping ions in an ion trapping assembly is described. In one aspect, this is implemented by introducing ions into the ion trapping assembly, applying a first RF trapping amplitude to the ion trapping assembly so as to trap introduced ions which have m/z ratios within a first range of m/z ratios, and cooling the trapped ions. In some aspects, also performed is reducing the RF trapping amplitude from the first RF trapping amplitude to a second, lower, RF trapping amplitude so as to reduce the low mass cut-off of the ion trapping assembly and trapping, at the second, lower RF trapping amplitude, introduced ions having m/z ratios within a second range of m/z ratios. A lower mass limit of the second range of m/z ratios is below the low mass cut-off of the ion trapping assembly when the first RF trapping amplitude is applied.

Ion trapping scheme with improved mass range

The present disclosure provides a mass spectrometer for performing an analysis of sample ions, and a method for operating a mass spectrometer. The mass spectrometer comprises a first ion optical element that is supplied with a first gas; a mass analyzer, wherein the performance of the mass analyzer is dependent on the pressure of the first gas in the first ion optical element; and a controller for setting a property of the first gas, which comprises at least the pressure of the first gas, on the basis of a characteristic of the analysis to be performed by the mass spectrometer.

Mass spectrometer

Disclosed herein is a mass spectrometry method having steps of: transmitting ions from an ion source through a mass filter; processing ions received from the mass filter in a discontinuous ion optical device downstream of the mass filter; operating the mass filter for a plurality of periods in a mass/charge ratio (m/z) filtering mode to transmit ions in one or more selected ranges of m/z to the discontinuous ion optical device; and operating the mass filter in a broad mass range mode transmitting ions of a mass range substantially wider than any mass range transmitted in the m/z filtering mode during one or more periods in which the discontinuous ion optical device is not processing ions from the mass filter. Utilization of this method assists to reduce contamination in the mass filter.

Method of operating a mass filter in mass spectrometry

A method is proposed for assessing the vacuum conditions in a mass spectrometer () such as an ion cyclotron resonance or orbital trapping mass spectrometer. Such mass spectrometers generate a transient detection signal resulting from ions of one or species in an ion trap (). The parameters of the trap and/or introduced ions are adjusted so as to cause the decay rate of the transient in respect of the ion species to be dominated by collisional effects. Typically this can be achieved by introducing ions into the trap () in quantities such that ion clouds of a particular ion species self bunch. The rate of decay of the transient signal in that case is determined and compared with one or more threshold decay rates. This in turn can provide an indication of vacuum conditions within the trap ().

Method of assessing vacuum conditions in a mass spectrometer with transient signal decay rates

A method of operating a gas-filled collision cell in a mass spectrometer is provided. The collision cell has a longitudinal axis. Ions are caused to enter the collision cell. A trapping field is generated within the collision cell so as to trap the ions within a trapping volume of the collision cell, the trapping volume being defined by the trapping field and extending along the longitudinal axis. Trapped ions are processed in the collision cell and a DC potential gradient is provided, using an electrode arrangement, resulting in a non-zero electric field at all points along the axial length of the trapping volume so as to cause processed ions to exit the collision cell. The electric field along the axial length of the trapping volume has a standard deviation that is no greater than its mean value.

Collision cell

A novel method and mass spectrometer apparatus is introduced to enable the simultaneous isolation of cations and anions (i.e., precursor and reagent ions) in a linear multipole ion trap via the application of an additional axial DC gradient in combination with coupled RF potential(s). Thus, the combination of the RF and DC voltages in such an arrangement forms a pseudopotential designed to provide for minima for the trapped positively and negatively charged particles that result in the overlap of the ion clouds so as to provide for beneficial ion/ion reactions.

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Bremen, Germany

Dirk Nolting