609results about "Specific reaction combinations" patented technology

This invention provides methods, devices and device components for preparing ions from liquid samples containing chemical species and methods and devices for analyzing chemical species in liquid samples. The present invention provides an ion source for generating analyte ions having a selected charge state distribution, such as a reduced charged state distribution, that may be effectively interfaced with a variety of charged particle analyzers, including virtually any type of mass spectrometer.

A means and method are disclosed whereby ions from an ion source can be selected and transferred to a time-of-flight mass analyzer via an arrangement of multipoles in such a way that fragmented ions may be generated by collision-induced dissociation or surface-induced dissociation. First, ions from the source are collisionally cooled by a first multipole. Second, the m / z range of the ions is then selected by a second multipole (preferably a quadrupole). Third, the selected ions are allowed to collide with a "collision surface" capable of producing fragment ions. Fourth, these fragment ions are collisionally cooled in a third multipole and delivered into a TOF mass analyzer for subsequent analysis of the fragmented ions.

A dual ion trap mass analyzer includes adjacently positioned first and second two-dimensional ion traps respectively maintained at relatively high and low pressures. Functions favoring high pressure (cooling and fragmentation) may be performed in the first trap, and functions favoring low pressure (isolation and analytical scanning) may be performed in the second trap. Ions may be transferred between the first and second trap through a plate lens having a small aperture that presents a pumping restriction and allows different pressures to be maintained in the two traps. The differential-pressure environment of the dual ion trap mass analyzer facilitates the use of high-resolution analytical scan modes without sacrificing ion capture and fragmentation efficiencies.

Systems and methods are used to store an electronic record of all product ion spectra of all detectable compounds of a sample. A plurality of product ion scans are performed on a tandem mass spectrometer one or more times in a single sample analysis across a mass range using a plurality of mass selection windows. All sample product ion spectra of all detectable compounds for each mass selection window are produced. All sample product ion spectra for each mass selection window are received from the tandem mass spectrometer using a processor. All sample product ion spectra for each mass selection window are stored as an electronic record of all detectable compounds of the sample using the processor. The electronic record is used to characterize compounds known at the time the electronic record is stored or to characterize compounds that became known after the electronic record was stored.

A method for fragmentation of analyte ions for mass spectroscopy and a system for mass spectroscopy. The method produces gas-phase analyte ions, produces gas-phase radical species separately from the analyte ions, and mixes the gas-phase analyte ions and the radical species at substantially atmospheric pressure conditions to produce fragment ions prior to introduction into a mass spectrometer. The system includes a gas-phase analyte ion source, a gas-phase radical species source separate from the gas-phase analyte ion source, a mixing region where the gas-phase analyte ions and the radical species are mixed at substantially atmospheric pressure to produce fragment ions of the analyte ions, a mass spectrometer having an entrance where at least a portion of the fragment ions are introduced into a vacuum of the mass spectrometer, and a detector in the mass spectrometer which determines a mass to charge ratio analysis of the fragment ions.

The invention relates generally to ion mobility-based systems, methods and devices for analyzing samples.

An electron capture dissociation device to implement a combination of electron capture dissociation and collision dissociation and a mass spectrometer with the use thereof are provided. This device includes a linear ion trap provided with linear multipole electrodes applied with a radio frequency electric field and wall electrodes that are arranged on both ends in the axis direction of the linear multipole electrodes, have holes on the central axis thereof, and generate a wall electric field by being applied with a direct-current voltage, a cylindrical magnetic field-generating unit that generates a magnetic field parallel to the central axis of the linear multipole electrodes and surrounds the linear ion trap, and an electron source arranged opposite to the linear multipole electrodes with sandwiching one of the wall electrodes. The electron generation site of the electron source is placed in the inside of the magnetic field generated by the magnetic field-generating unit.

Methods for fragmenting ions in an ion trap are described. These methods involve a) selecting parent ions for fragmentation; b) retaining the parent ions within the ion trap for a retention time interval, the ion trap having an operating pressure of less than about 1×10-4 Torr; c) providing a RF trapping voltage to the ion trap to provide a Mathieu stability parameter q at an excitement level during an excitement time interval within the retention time interval; d) providing a resonant excitation voltage to the ion trap during the excitement time interval to excite and fragment the parent ions; e) providing a non-steady-state pressure increase of at least 10% of the operating pressure within the ion trap by delivering a neutral gas into the ion trap for at least a portion of the retention time interval to raise the pressure in the ion trap to a varying first elevated-pressure in the range between about 6×10-5 Torr to about 5×10-4 Torr for a first elevated-pressure duration; and f within the retention time interval and after the excitement time interval, terminating the resonant excitation voltage and changing the RF trapping voltage applied to the ion trap to reduce the Mathieu stability parameter q to a hold level less than the excitement level to retain fragments of the parent ions within the ion trap. The excitation time interval and the first elevated-pressure duration substantially overlap in time.

A mass spectrometric method for determining the position of unsaturation in a compound is disclosed.

A method of mass spectrometry having the steps of, in a first cycle: storing sample ions in a first ion storage device; ejecting the stored ions out of the first ion storage device into a separate ion selection device; selecting a subset of the ions in the ion selection device; ejecting the subset of ions selected within the ion selection device to a fragmentation device; directing ions from the fragmentation device back to the first ion storage device without passing them through the said ion selection device; receiving at least some of the ions ejected from the first ion storage device, or their derivatives, back into the first ion storage device; and storing the received ions in the first ion storage device.

Methods and apparatus for data-dependent mass spectrometric MS / MS or MSn analysis are disclosed. The methods may include determination of the charge state of an ion species of interest, followed by automated selection of a dissociation type (e.g., CAD, ETD, or ETD followed by a non-dissociative charge reduction or collisional activation) based at least partially on the determined charge state. The ion species of interest is then dissociated in accordance with the selected dissociation type, and an MS / MS or MSn spectrum of the resultant product ions may be acquired.

Systems and methods of generating ions at atmospheric pressure are presented. These systems and methods include spatially dependent analysis of a sample using an effusive ionization source. Systems and methods of isolating samples at atmospheric pressure are presented. These systems and methods include using a barrier to prevent metastables or electrons from an effusive ion source from reaching a sample unless the sample is in an analysis position. Systems and methods of using metastables in collisionally induced dissociation are presented.

The present invention relates to a method and apparatus for ionizing a neutral MALDI desorption plume, and in particular, for efficiently measuring the ionized MALDI desorption plume when post-ionization techniques are combined with a medium pressure MALDI-IM-oTOFMS instrument. Additionally, the present disclosure provides a method and apparatus that simultaneously separates tissue-sample MALDI ions by IM-oTOFMS according to their chemical family. After separation, the MALDI ions are directly compared to the ions created by post-ionizing the co-desorbed neutral molecules with a second laser wherein the second laser is delayed by a few hundred microseconds. The present disclosure further provides novel approaches that enhance the analysis of ions, including the use of giant fullerene internal standards to enhance mass accuracy, and ultraviolet (UV) declustering lasers to generate intact peptides and proteins, either of which may be followed by VUV post-ionization which generates identifiable structural fragments.

A multi-reflection mass spectrometer comprising two ion-optical mirrors, each mirror elongated generally along a drift direction (Y), each mirror opposing the other in an X direction and having a space therebetween, the X direction being orthogonal to Y; the mass spectrometer further comprising one or more compensation electrodes each electrode being located in or adjacent the space extending between the opposing mirrors; the compensation electrodes being configured and electrically biased in use so as to produce, in at least a portion of the space extending between the mirrors, an electrical potential offset which: (i) varies as a function of the distance along the drift length, and / or; (ii) has a different extent in the X direction as a function of the distance along the drift length. In a preferred embodiment the period of ion oscillation between the mirrors is not substantially constant along the whole of the drift length.

Provided is a plasma ion source mass spectrometer with an ion deflector lens having an improved removal ratio of photons and neutral particles as compared with the conventional art while an ion transmittance is maintained. The ion deflector includes an input side plate-like electrode, an output side plate-like electrode, and a tubular electrode disposed between the input side plate-like electrode and the output side plate-like electrode. The tubular electrode is of a point asymmetrical configuration. The tubular electrode is arranged so that a center axis of the tubular electrode is closer to an axis of travel of ions upstream of the input side plate-like electrode than an axis of travel of ions downstream of the output side plate-like electrode.

Improved ion focusing for an ion mobility drift cell allows for improved throughput for subsequent detection such as mass detection. Improved focusing is realized by the use of alternating regions of high and low electric fields in the ion mobility drift cell.

A mass spectrometer is disclosed comprising a collision cell wherein ions having substantially different mass to charge ratios are arranged to be transmitted through at least a portion of the collision cell at substantially the same time and with substantially the same velocity preferably by means of one or more transient DC voltages or one or more transient DC voltage waveforms which are applied to the electrodes forming the collision cell so that ions are urged through the collision cell at a constant controlled velocity. By appropriate setting of the velocity of the DC voltage or DC voltage waveform passing along the length of the collision cell an efficient collision cell is provided which is able to fragment ions having considerably different mass to charge ratio at substantially the same time in an optimal manner.

A distance of flight (DOF) approach to mass spectroscopy in which the resolution among the various ion masses is accomplished in space rather than time. A separate detector is associated with each ion mass resolution element. The DOF mass spectrometer can serve as one element in a tandem arrangement which has the capability to produce a full two-dimensional precursor / product spectrum for each bunch of ions extracted from the source. A “distance-of-flight” (DOF) mass analyzer is used in combination with time-of-flight (TOF) mass analysis for precursor and product dispersion. All the precursor ions can undergo a mass changing reaction simultaneously, while still retaining the essential information about the particular precursor m / z value from which each product ion m / z value emanated. Through the use of a two-dimensional detector, all the products ions from all the precursors can be detected for each batch of ions analyzed.

The invention provides a system apparatus and methods for fragmenting various molecules. In particular, the invention may be employed for fragmenting biomolecules like peptides to determine sequence information. The invention provides a mass spectrometry system for photo-activated collision induced dissociation. The mass spectrometry system or device includes an ion source for producing ions, a photon source adjacent to the ion source for photo-activating ions produced by the ion source, an electrical element adjacent to the photon source for creating an electric field for accelerating ions produced by the ion source and photo-activated by the photon source; wherein ions are produced by the ion source, photo-activated by the photon source and accelerated into a surface to cause dissociation of the activated ions; and a detector downstream from the ion source for detecting the collision induced and dissociated ions.Methods for molecule and / or peptide fragmentation are also disclosed.