The invention is related to a trapped ion mobility spectrometer (TIMS device) and proposes to use higher order (order N>2) linear multipole RF systems to accumulate and analyze ions at an electric DC field barrier, either pure higher order RF multipole systems or multipole RF systems with transitions from higher order towards lower order, e.g. from a linear octopolar RF system (N=4) to a linear quadrupole RF system (N=2) in front of the apex of the electric DC field barrier.

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.

The invention is related to a trapped ion mobility spectrometer (TIMS device) and proposes to use higher order (order N>2) linear multipole RF systems to accumulate and analyze ions at an electric DC field barrier, either pure higher order RF multipole systems or multipole RF systems with transitions from higher order towards lower order, e.g. from a linear octopolar RF system (N=4) to a linear quadrupole RF system (N=2) in front of the apex of the electric DC field barrier.

With regard to an object of the invention, in a tandem type mass spectrometry system including three stages of a QMS, sensitivity of a daughter ion decreases due to loss resulting from destabilization of the daughter ion or a decrease in daughter ion generation rate, and an improvement insensitivity of the daughter ion is a significant issue. To solve the above-mentioned problem, the invention provides a mass spectrometry system having means of decreasing a q value of a parent ion and not decreasing a fundamental vibration frequency of the parent ion. According to the means of the invention, the invention may have effects that a mass number range of a daughter ion that may be stably transmitted is expanded, the number of vibrations of a parent ion is substantially the same as that in a first stage of the QMS, and generation efficiency of the daughter ion does not decrease and can be maintained.

The present invention relates to the technical field of mass analysis instruments. Disclosed is an ion excitation method in a linear ion trap. The method comprises: in a linear ion trap, and at an ion collision-induced dissociation stage, simultaneously applying an auxiliary excitation signal in radial X and Y directions thereof; increasing the kinetic energy of ions in the two directions, thereby increasing collisions with a center gas to cause dissociation; and converting the kinetic energy to internal energy to achieve tandem mass spectrometry analysis. The kinetic energy in the X and Y directions of the ion is increased, and compared to a conventional dissociation method in which ions are primarily excited in one direction, more kinetic energy is converted to internal energy, thus improving dissociation efficiency, shortening reaction time, and addressing a low mass cutoff effect in the ion trap.

With regard to an object of the invention, in a tandem type mass spectrometry system including three stages of a QMS, sensitivity of a daughter ion decreases due to loss resulting from destabilization of the daughter ion or a decrease in daughter ion generation rate, and an improvement insensitivity of the daughter ion is a significant issue. To solve the above-mentioned problem, the invention provides a mass spectrometry system having means of decreasing a q value of a parent ion and not decreasing a fundamental vibration frequency of the parent ion. According to the means of the invention, the invention may have effects that amass number range of a daughter ion that may be stably transmitted is expanded, the number of vibrations of a parent ion is substantially the same as that in a first stage of the QMS, and generation efficiency of the daughter ion does not decrease and can be maintained.

Systems and methods are provided for selecting and fragmenting a first precursor ion in an MS3 experiment. One or more first excitation parameters are calculated that define a first dipole excitation using a processor. The first dipole excitation is used to select a first precursor ion and fragment the first precursor ion to produce a second precursor ion. The first dipole excitation is applied to the continuous beam of ions by sending a first set of data including the first excitation parameters to a mass spectrometer. The first set of data is sent so that a first quadrupole applies the first dipole excitation to a continuous beam of ions. The mass spectrometer includes an ion source that provides the continuous beam of ions and the first quadrupole that receives the continuous beam of ions and is adapted to apply dipole excitation to the continuous beam of ions.

A method of quantitative mass analysis of precursor species of different mass-to-charge (m/z) ratios from a single or the same ion injection event is disclosed. A plurality of precursor ion species having different respective m/z ratios are introduced into a mass spectrometer at the same time. The precursor ion species are isolated. A first subset of the isolated precursor ions having a first m/z ratio is fragmented and analyzed. A second subset of the isolated precursor ions having a second m/z ratio is fragmented and analyzed. A first mass spectrum is generated for the fragment ions of the first subset of precursor ions, and a second mass spectrum is generated for the fragment ions of the second subset of precursor ions.

This invention is related to a tandem mass spectrometric analysis method in ion trap mass analyzer. Such method comprise three stages as represented by selective isolation, collision induced disassociation and mass scanning of ion. At the collision induced isolation stage, this invention is expected to endow parent ion of certain mass-charge ratio with energy through resonance excitation by changing cycle of radio frequency signals, namely frequency of radio frequency voltage imposed on the ion trap; such high-energy ions produced through resonance excitation are to be disassociated through collision with neutral molecules in the ion trap, which will further generate product ion to realize tandem mass spectrometric analysis. Advantage of this method lies in the fact that it can realize collision induced disassociation by changing scanning cycle at the stage of collision induced disassociation stage through software configuration, which can significantly simplify experimental devices and methods for tandem mass spectrometric analysis.

A method of dissociation of an oligonucleotide in a mass spectrometer includes introducing the oligonucleotides into an electrospray ionization source operated in a negative mode to cause deprotonation of said oligonucleotide for generating a negatively charged ion of said oligonucleotides, trapping said negatively charged oligonucleotide ions in linear radiofrequency (RF) ion traps with T bar electrodes, filling the linear ion trap with a buffer gas, and using a resonant dipole AC excitation signal applied to the T bar electrodes to resonantly excite the negatively charged oligonucleotide ions at secular frequencies thereof to cause selective fragmentation of said negatively charged oligonucleotide ions via collision with molecules of said buffer gas.