Abstract:
A mass spectrometer is disclosed comprising a liquid chromatography device for separating ions. A gas phase ion-neutral reaction device is arranged downstream to perform a gas phase ion-neutral reaction such as Hydrogen-Deuterium exchange. A control system is arranged to automatically and repeatedly switch the reaction device back and forth between a first mode of operation and a second mode of operation, wherein in the first mode of operation at least some parent or precursor ions are caused to react within the reaction device and wherein in the second mode of operation substantially fewer or no parent or precursor ions are caused to react.
Abstract:
A pulsed ion source is disclosed wherein the ion source is energized one or more times to generate a first group of ions and a second group of ions. The first and second groups of ions are simultaneously transmitted through an ion guide whilst keeping the first and second groups of ions isolated from each other.
Abstract:
A mass spectrometer is disclosed comprising a quadrupole rod set ion guide or mass filter device (6). A broadband frequency signal (10) having one or more notches (11a, 11b, 11c) is applied to the rods of the quadrupole rod set (6). The notched broadband frequency signal (10) causes undesired ions to be resonantly ejected from the ion guide (6). The notched broadband frequency signal (10) has frequency components missing which correspond with the resonance frequency of ions which are desired to be onwardly transmitted. The ion guide or mass filter device (6) enables a plurality of desired ions having different mass to charge ratios to be simultaneously transmitted by the ion guide or mass filter device (6) whilst other ions are resonantly ejected from the ion guide or mass filter device (6).
Abstract:
A method of screening a sample for the presence of one or more known compounds of interest is disclosed. A fragmentation device is repeatedly switched between a fragmentation mode of operation and a non-fragmentation mode of operation. A determination is made whether a candidate parent ion of interest is present in a non-fragmentation data set and whether one or more corresponding fragment ions of interest are present in a fragmentation data set. A further determination is made to check if the candidate parent ion of interest and the one or more corresponding fragment ions of interest have substantially similar elution or retention times and/or ion mobility drift times.
Abstract:
A pulsed ion source is disclosed wherein the ion source is energised one or more times to generate a first group of ions and a second group of ions. The first and second groups of ions are simultaneously transmitted through an ion guide whilst keeping the first and second groups of ions isolated from each other.
Abstract:
A mass spectrometry electron transfer dissociation reagent comprising an unsaturated compound having a Frank Condon factor between 0.1 and 1.0 and an electron affinity having a positive value between 0.1 to 150 kJ/mol.
Abstract:
A mass spectrometer is disclosed comprising a Gas Electron Multiplier ion detector. The ion detector comprises three gas electron multiplier stages GEM1, GEM2, GEM3 wherein a counter electrode (12) is arranged adjacent the first electron multiplier stage GEM1.
Abstract:
An ion guide or ion trap (1) is disclosed having an entrance electrode (2) and an exit electrode (3). The potential of the exit electrode (3) is periodically dropped for a relatively short period of time allowing some ions to escape from the ion guide or ion trap (1) via an aperture in the exit electrode (3). The period of time that the potential of the exit electrode (3) is dropped for is progressively increased and ions emerge from the ion guide or ion trap (1) in a mass to charge ratio dependent manner. The ion guide or ion trap (1) may be operated as a mass separator or low resolution mass analyser.
Abstract:
A mass spectrometer is disclosed comprising a quadrupole rod set ion guide or mass filter device. Broadband frequency-signals (13, 14, 15) having a plurality of frequency notches (16a; 16b; 16c) are applied sequentially to the rods of the quadrupole rod set. The notched broadband frequency signals (16a, 16b, 16c) cause undesired ions to be resonantly or parametrically ejected from the ion guide. The resulting ion signals are deconvoluted to provide a mass spectrum.
Abstract:
A mass spectrometer is disclosed comprising a quadrupole rod set ion guide or mass filter device (6). A broadband frequency signal (10) having one or more notches (11a, 11b, 11c) is applied to the rods of the quadrupole rod set (6). The notched broadband frequency signal (10) causes undesired ions to be resonantly ejected from the ion guide (6). The notched broadband frequency signal (10) has frequency components missing which correspond with the resonance frequency of ions which are desired to be onwardly transmitted. The ion guide or mass filter device (6) enables a plurality of desired ions having different mass to charge ratios to be simultaneously transmitted by the ion guide or mass filter device (6) whilst other ions are resonantly ejected from the ion guide or mass filter device (6).