99results about "Positive/negative analyte ion analysis/introduction/generation" patented technology

An ion mobility / mass spectrometry method and instrument using aerosolized samples and dual positive and negative mode detection is described. Sample preparation methods are also described.

The invention relates to a reaction cell for reactions between different types of ion species and a related mass spectrometer to analyze the ion products. The invention consists in an RF-operated straight ion guide with a side inlet, particularly suitable for reactions between positive and negative ion species, one ion species being fed in through the side inlet. Particularly favorable is an ion guide made up of a set of coaxial apertured diaphragms with a slight axial potential gradient. The reactions can be used for a fragmentation of multiply charged protein or peptide ions by electron transfer, or for the removal of excess charges of multiply charged biopolymer ions, for example.

The present invention is concerned with a device for charged particle transportation and manipulation. Embodiments provide a capability of combining positively and negatively charged particles in a single transported packet. Embodiments contain an aggregate of electrodes arranged to form a channel for transportation of charged particles, as well as a source of power supply that provides supply voltage to be applied to the electrodes, the voltage to ensure creation, inside the said channel, of a non-uniform high-frequency electric field, the pseudopotential of which field has one or more local extrema along the length of the channel used for charged particle transportation, at least, within a certain interval of time, whereas, at least one of the said extrema of the pseudopotential is transposed with time, at least within a certain interval of time, at least within a part of the length of the channel used for charged particle transportation.

An ion detector comprises an ion guide with electrodes arranged about a first axis; a positive ion detection device with an ion inlet at a first side of the ion output section offset from and at an angle to the first axis; and a negative ion detection device with an ion inlet at a second side opposite the first side, offset from and at an angle to the first axis. A negative voltage bias applied to the positive ion device accelerates positive ions toward the inlet along a path including a component along a second axis orthogonal to the first axis. A positive voltage bias applied to the negative ion detection device accelerates negative ions toward the inlet along a path that includes a component along the second axis orthogonal to the first axis in a direction generally opposite to the path of the positive ions.

A dual-polarity mass spectrometer includes an ion source, a negative ion mass analyzer, and a positive ion mass analyzer to measure both the negative and positive ion spectra of a sample material simultaneously. The ion source includes a sample surface on which the sample material is positioned, the sample material providing positive ions and negative ions when excited by a laser beam or an energetic particle stream. A first extraction electrode is connected to a voltage higher than the sample surface to attract the negative ions from the sample electrode. A second extraction electrode is connected to a voltage lower than the sample surface to attract the positive ions from the sample electrode. The negative and positive ions are analyzed simultaneously by the negative ion mass analyzer and the positive ion mass analyzer, respectively.

A mass spectrometer having an ion source section capable of creating positive ions and negative ions at high efficiency. The ion source is comprised of an ion source section for creating ions of a sample gas, a mass spectrometric section for conducting mass separation of created ions, linear RF generating multipole electrodes, magnetic fields generation means, a sample gas introduction system, a reaction gas introduction system and an electron source in which the linear RF generating multipole electrodes generate linear RF multipole electric fields. A static magnetic fields is applied in parallel on the center axis where the linear RF multipole electric fields are zero. A sample gas and a reagent gas are introduced into the ion source section. Electrons are injected for creating reaction of the positive ions or negative ions.

A mass spectrometer suitable to measure both positive and negative particles, such as ions for example in a vacuum chamber. This spectrometer is provided with a turnable permanent magnet segment, which provides the gap of a yoke with adequate magnetic flux having the appropriate direction to separate the positive or the negative particles. Changing the polarity adjusts the flight path of the ions. Thus, negatively charged ions and positively charged ions will follow similar flight paths under opposite polarities, permitting the use of a single array of detectors. One or more coils may be used in place of or in addition to the turnable permanent magnet segment in order to provide the appropriate magnetic flux to the gap, and / or facilitate the turning process of the turnable magnet segment. The turnable magnet and / or the coils may be inside or outside the vacuum chamber. The detector may comprise at least one detector area, two charge mode amplifiers coupled to the detector area, a first CCD shift register coupled to a first one of the charge mode amplifiers and a second CCD shift register coupled to a second one of the charge mode amplifiers.

The applicants' teachings provide methods, systems, and apparatus useful in operating mass spectrometers and other devices incorporating multipole rod sets or other multi-electrode devices to simultaneously contain ions of both positive and negative charges through the simultaneous application to the rods or other electrodes of both radio-frequency (RF) and alternating (AC) currents.

There is provided a linear ion trap having an ion guide and a method of operating same. The ion guide has a first end and a second end. The method involves a) providing a first group of ions within the ion guide; b) providing a second group of ions within the ion guide, the second group of ions being opposite in polarity to the first group of ions; c) providing an RF drive voltage to the ion guide to radially confine the first group of ions and the second group of ions in the ion guide; d) providing a gas flow of an inert gas in a first axial direction away from the first end of the ion guide and toward a middle of the ion guide to repel both the first group of ions and the second group of ions from the first end of the ion guide; and, e) providing a trapping region barrier for repelling both the first group of ions and the second group of ions away from the second end of the ion guide. The gas flow in the first axial direction and the trapping region barrier together define a main trapping region for trapping both the first group of ions and the second group of ions.

An apparatus and method are disclosed for efficient detection of ions ejected from a quadrupolar ion trap, in which the ions are ejected as first and second groups of ions having different directions. The first and second groups of ions are received by a conversion dynode structure, which responsively emits secondary particles that are directed to a shared detector, such as an electron multiplier. The conversion dynode structure may be implemented as a common dynode or as two dynodes (or sets of dynodes), with each dynode positioned to receive one of the groups of ions.

A mass spectrometric apparatus capable of generating and detecting positive and negative ions stably at the same time. The apparatus preferably comprises: an opening through which a sample gas is introduced; an ion source to generate ions of the sample gas; and a mass spectrometer to analyze the mass of the generated ions. The ion source utilized with the mass spectrometric device comprises: a first needle electrode on which a voltage is applied in order to generate positive ions of the sample gas introduced through the opening; a first counter electrode having a first opening through which the sample gas and the positive ions pass; a second counter electrode disposed opposite the first counter electrode having a second opening through which the sample gas and the positive ions pass; a second needle electrode on which voltage is applied in order to generate negative ions of the sample gas; and a vent through which the sample gas is ejected. Generated ions are then introduced into a vacuum region via an aperture and subjected to mass analysis.

An angled dual-polarity mass spectrometer includes a dual-polarity ion generator, a first mass analyzer, and a second mass analyzer. The dual-polarity ion generator includes an ion source to generate positive ions and negative ions from a sample, and electrodes to generate electric fields for guiding the negative ions into a beam of negative ions and guiding the positive ions into a beam of positive ions. The first mass analyzer can analyze the negative ions, and the second mass analyzer can analyze the positive ions. The central axes of the first and the second mass analyzers are at an angle between 0 to 179 degrees.