Abstract:
A system and method is described for characterizing glycopeptides which includes a first quadrupole mass filter, a multipole rod set of an ion guide, a lens electrode, an ExD device and a mass analyzer. The multipole rod set is adapted to receive a radial radio frequency (RF) trapping voltage and a radial dipole direct current (DC) voltage The lens electrode is adapted to receive an axial trapping alternating current (AC) voltage and a DC voltage. The ExD device performs electron capture dissociation or electron transfer dissociation, the ExD device being positioned so that an entrance of the ExD device is disposed on the other side of the lens electrode opposite the multipole rod set. The mass analyzer is positioned at an exit of the ExD device for receiving ions from the ExD device.
Abstract:
A quadrupole ion trap apparatus includes a main electrode, a first end-cap electrode, a second end-cap electrode, and a phase-controlled waveform synthesizer.The phase-controlled waveform synthesizer generates a main RF waveform for the main electrode. The main RF waveform includes a plurality of sinuous waveform segments each of which is a part of a sine wave, and a plurality of phase conjunction segments each of which is non-sinuous. Each of the sinuous waveform segments is bridged to another sinuous waveform segment via one of the phase conjunction segments, so as to perform ordering of micro motions of sample ions trapped by the electrodes.
Abstract:
A method of filtering ions (16) is disclosed comprising: providing an ion filter (6) having an ion entrance, an ion exit and a plurality of electrodes (18); applying an AC and/or RF voltage to at least a first electrode so as to generate a pseudo-potential barrier; and urging ions towards the pseudo-potential barrier as they travel from the entrance to the exit whilst maintaining the ion filter (6) at a pressure such that first ions are repelled by the pseudo- potential barrier and so are transmitted through the filter to said exit, whereas second ions having substantially the same mass to charge ratio as the first ions but a lower mass are not capable of being repelled by the pseudo-potential barrier and reaching said exit.
Abstract:
There is provided a method comprising separating a first population of ions according to a first physico-chemical property in a first separation device, and separating one or more groups of ions emerging from the first separation device in a drift tube and sampling each group of ions using the drift tube to determine the collision cross section of ions in each group of ions, wherein each group of ions corresponds to a range of the first physico-chemical property. The drift tube is configured such that multiple groups of ions in the first population of ions can be sampled by the drift tube in a single cycle of separation of the first separation device. The step of sampling each group of ions comprises determining the mobility of ions in each group of ions by measuring their drift time through the drift tube, and determining the collision cross section of the ions in each group of ions using the determined mobility.
Abstract:
The present disclosure relates to novel and improved methods of analyzing proteins, peptides and polypeptides by mass spectrometry using ion-ion reactions. More specifically the disclosure relates to improved methods for implementing the m/z selective arresting of ion-ion reactions within the ion-ion reaction cell of a mass spectrometer system during a period where ion-ion reactions are performed.
Abstract:
Improvements to a side-on Penning trap include methods to stabilize ions in the trap. The ions are stabilized by injecting ions in the focusing region of the non-uniform DC fields produced by the pad electrodes of the trap. Ions are injected along an injection axis shifted from the central axis of a gap between a positively biased electrode pad and negatively biased electrode pad of the trap. Improvements also include methods to compensate for the Lorentz force that is produced when ions are injected into a side-on Penning trap. Electrodes of an ion injection device are DC biased so that the electrodes produce an electric field along the axis of the device that compensates for the Lorentz force. Finally, methods are provided to increase the m/z range of ions injected into a side-on Penning trap by pre-trapping ions just before injection of the ions into the trap.