The present invention addresses ways to facilitate the detection and analysis of ion abundance, in particular for analysis of elemental ions, and in particular embodiments for isotope ratio analysis, by use of collision cells that employ an axial drag field, i.e. an axial electric field that exerts a drag force on ions within the cell. By means of the invention, the drag field allows an increase in the transmission in the case of Li from a few % up to almost 100%. The drag field is generated by electric fields and can be switched on and off within microsecond (μs) timescales and thus improves the sensitivity for the lighter elements dramatically. The invention allows use of collision cells for analysis of elemental ions in a simple and fast workflow with high throughput and without compromising transmission.

A method of processing ions in a mass spectrometer comprises introducing one or more precursor ions into a collision cell to fragment at least a portion of said ions, where the collision cell is configured to confine ions having m/z ratios above a selected threshold (i.e., high m/z ions). The ions are released from the collision cell and introduced into a downstream analyzer ion trap to radially confine high m/z ions. The collision cell and the analyzer ion trap are configured to confine ions having m/z ratios below said selected threshold (i.e., low m/z ions). Ions are introduced into the collision cell and undergo fragmentation. The fragment ions are released from the collision cell and introduced into the analyzer ion trap, thus loading the analyzer ion trap with both high m/z and low m/z ions. The ions are released from the analyzer ion trap and detected by a detector.

A mass spectrometer collision cell system, comprising: a gas containment vessel comprising an internal chamber having ion inlet and ion outlet ends and a cross-sectional area, A.sub.chamber; a gas inlet aperture; first and second gas outlet apertures that are disposed at or proximal to the ion inlet and outlet ends, respectively, and that have respective outlet aperture cross-sectional areas, A.sub.aperture1 and A.sub.aperture2, and an average outlet aperture cross-sectional area, A.sub.aperture.sup.ave; a longitudinal axis of the chamber extending from the ion inlet end to the ion outlet end and having a length, L.sub.chamber; and a set of multipole rod electrodes, at least a portion of each multipole rod electrode being within the chamber, wherein the values of A.sub.chamber, L.sub.chamber and A.sub.aperture.sup.ave are such that the combined gas conductance of the chamber and the gas outlet apertures is not greater than 95 percent of the gas conductance of the gas outlet apertures alone.

A nozzle for an ionisation source comprises: a light passage having an inlet end and an outlet end; and a gas flow passage in fluid communication with the light passage, wherein the gas flow passage is configured to convey, in use, a flow of gas into the light passage such that the flow of gas travels substantially towards the outlet end of the light passage.

The ion trap comprises a multipole electrode assembly, a first confining electrode, and a second confining electrode. The multipole electrode assembly is configured to confine ions of the first polarity to an ion channel extending in an axial direction of the multipole electrode assembly. The first confining electrode is provided adjacent to the multipole electrode assembly and extends in the axial direction of the multipole electrode assembly. The second confining electrode is provided adjacent to the multipole electrode assembly and extends in the axial direction of the multipole electrode assembly aligned with the first confining electrode. The first and second confining electrodes are spaced apart in the axial direction in order to define an ion confining region of the ion channel between the first and second confining electrodes. The first and second confining electrodes are configured to receive a DC potential of the first polarity to further confine ions within the ion channel in the ion confining region.

A device and associated method are disclosed for interfacing an ion trap to a pulsed mass analyzer (such as a time-of-flight analyzer) in a mass spectrometer. The device includes a plurality of separate confinement cells and structures for directing ions into a selected one of the confinement cells. Ions are ejected from the ion trap in a series of temporally successive ion packets. Each ion packet (which may consist of ions of like mass-to-charge ratio), is received by the ion interface device, fragmented to form product ions, and then stored and cooled in the selected confinement cell. Storage and cooling of the ion packet occurs concurrently with the receipt and storage of at least one later-ejected ion packet. After a predetermined cooling period, the ion packet is released to the mass analyzer for acquisition of a mass spectrum.

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.

A nozzle for an ionisation source comprises: a light passage having an inlet end and an outlet end; and a gas flow passage in fluid communication with the light passage, wherein the gas flow passage is configured to convey, in use, a flow of gas into the light passage such that the flow of gas travels substantially towards the outlet end of the light passage.

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.

A method of processing ions in a mass spectrometer comprises introducing one or more precursor ions into a collision cell to fragment at least a portion of said ions, where the collision cell is configured to confine ions having m/z ratios above a selected threshold (i.e., high m/z ions). The ions are released from the collision cell and introduced into a downstream analyzer ion trap to radially confine high m/z ions. The collision cell and the analyzer ion trap are configured to confine ions having m/z ratios below said selected threshold (i.e., low m/z ions). Ions are introduced into the collision cell and undergo fragmentation. The fragment ions are released from the collision cell and introduced into the analyzer ion trap, thus loading the analyzer ion trap with both high m/z and low m/z ions. The ions are released from the analyzer ion trap and detected by a detector.