Agilent Technologies, Inc.

Hewlett-packard Company

Charles William Russ, Iv

Steven Michael Fischer

Robert Keith Crawford

Harry F Prest

Jeffrey T Kernan

Jerry T Dowell

Frank Erich Kuhlmann

Gangqiang Li

William Daniel Frazer

William E Barry

Jeffery S Hollis

Donald A Johnson

In a mass spectrometer or gas chromatograph/mass spectrometer system, one or more different conditioning gases are added to condition or modify one or more surfaces or regions of the ion source. The conditioning gas(es) may be added directly into the ion source. The conditioning gas may be added off-line, when the mass spectrometer is not analyzing a sample.

In-situ conditioning in mass spectrometry systems

An ion source is configured for electron ionization and produces coaxial electron and ion beams. The ion source includes an ionization chamber along an axis, a magnet assembly configured for generating an axial magnetic field in the ionization chamber, an electron source, and a lens assembly configured for directing the ion beam out from the ionization chamber along the axis, reflecting the electron beam back toward the electron source, and transmitting higher energy ions out from the ion source while reflecting lower energy ions toward a lens element for neutralization.

Axial magnetic ion source and related ionization methods

Systems and methods are provided for optimizing the performance of a mass spectrometer system when multiple measurements are made. For example, the total settling time of different components or stages of a mass spectrometer, such as a tandem mass spectrometer, are decreased by optimally ordering the measurements.

Systems and methods for decreasing settling times in MS/MS

A tandem mass spectrometer and method for calibrating a tandem mass spectrometer. The tandem mass spectrometer comprises first and second mass analyzers. The first and second mass analyzers form an ion path. The second mass analyzer is positioned downstream from the first mass analyzer and is arranged to receive ions from the first mass analyzer. An electrode arrangement positioned between the first and second mass analyzers. The electrode assembly is configured to selectively deflect ions from the ion path.

Mass spectrometry system having ion deflector

A mass calibration apparatus for a mass spectrometer includes a capillary, an analyte ion source coupled to the capillary at a first point, a reference mass ion source coupled to the capillary at a second point, downstream from the first point and a mass analyzer coupled to the capillary at a third point downstream from the first and second points. The reference mass ion source may be coupled to the capillary via a tee junction. The reference mass ion source includes a chamber, an ionization device situated within the chamber and one or more reference mass sources that are situated internally within the chamber or are situated external to and coupled to the chamber.

Reference mass introduction via a capillary

For generation and delivery of ions from an ionization chamber through an ion entrance orifice to a mass analyzer operating at high vacuum, high pass ion filtration is effected within the ionization chamber by application of electrical potentials to an electrode associated with the ion entrance orifice and to an electrode between the ionization region and the ion entrance orifice to create a retarding electric field upstream from the ion entrance orifice. The retarding electric field hinders the movement to the ion entrance orifice of ions having drift velocities below a lower limit, and as the retarding voltage gradient is made steeper, the lower limit increases.

Atmospheric pressure ion source high pass ion filter

The invention provides an apparatus for focusing ions exiting a multipole mass filter. In general terms, the ion focusing apparatus comprises: a housing having an ion entrance and an ion exit, and, contained within the housing: a) a multipole ion guide having an open ion entrance end, and b) a neutral gas. The ion focusing apparatus is configured so that an ion beam enters the housing via the ion entrance and is collisionally focused by the multipole ion guide and neutral gas prior to exiting the housing. The apparatus is readily employed to collisionally focus an ion beam exiting a quadrupole mass filter. Also provided is a mass spectrometry system containing the ion focusing apparatus, and methods employing the same.

Ion beam focusing device

An apparatus and method for calibrating a mass spectrometer by internally introducing calibration masses at a post-source stage of the mass spectrometer is provided. A source of lock mass ions adjacent the ion optics creates lock mass ions within the ion optics. Lock mass ions mix with the analyte ions in the ion optics prior to mass analysis. The source of lock mass ions may include various means for ionizing lock mass molecules including but not limited to photoionization, field desorption-ionization, electron ionization, and thermal ionization means. An apparatus and method of mass calibrating a tandem mass spectrometer is also provided. The mass calibration apparatus includes a collision cell for fragmenting analyte ions and a source of lock mass ions adjacent said collision cell for creating lock mass ions in the collision cell.

Internal introduction of lock masses in mass spectrometer systems

A system and method of processing signals generated at a detector of a mass spectrometer prior to signal conversion in which a pre-ADC offset is applied to the signals that is adjustable in polarity and magnitude in accordance with a user-selected mode. According to a first mode, a positive offset is applied to the signals to improve quantitation accuracy and in a second mode, a negative offset is applied to the signals to improve resolution and mass assignment.

Multi-mode signal offset in time-of-flight mass spectrometry

For delivery of ions from a higher pressure ion source to a mass analyzer operating at high vacuum, high pass ion filtration is effected within a dielectric capillary interface between the higher pressure ionization chamber and the lower pressure environment of a mass analyzer, by application of electrical potentials to end electrodes and to at least one electrode associated with the dielectric capillary between the ends, to create an end-to-end electric field generally opposing gas flow-assisted movement of ions from the upstream end to the downstream end, and to create a steeper voltage gradient along an upstream portion than along a downstream portion of the capillary. The voltage gradient along the steeper upstream portion of the capillary is sufficiently steep to cause ions having drift velocities below a lower limit to stall within the capillary. The respective potentials may be adjusted to increase the steepness of the upstream voltage gradient to increase the drift velocity lower limit.

Dielectric capillary high pass ion filter

An apparatus for delivering ions between vacuum stages. The apparatus includes a concave electrode ion pipe originating in a first vacuum stage and terminating in a second vacuum stage. The design of the concave electrode ion pipe provides for transport of ions over long distances without substantial loss of the ions while at the same time restricting overall gas flow. The invention allows for the elimination of vacuum stages or a reduction in vacuum pumping speed(s) if the same number of vacuum stages is employed.

Concave electrode ion pipe

Apparatus and methods are disclosed for manipulating charged particles. The charged particles are directed from a source thereof into a zone. A first electrical potential is generated in the zone. Simultaneously, a second electrical potential is generated outside the zone. The second electrical potential penetrates into the zone and combines with the first electrical potential to form an oscillating electric potential field having predetermined characteristics sufficient to manipulate the charged particles. The manipulating of the charged particles includes, e.g., transporting, collisional cooling, collisional induced dissociating and collisional focusing. In one embodiment an apparatus comprises a hollow first element and a hollow second element. The second element is disposed within the first element. The second element has at least two openings in a wall thereof. The openings are elongated and radially disposed with respect to the axis of the second element. The length of the openings is at least about 20% of the length of the second element The first element and the second element each are adapted independently to receive a voltage to generate within the second element an electric potential having predetermined characteristics. The apparatus and methods of the invention have particular application to the field of mass spectrometry.

Growing community of inventors

Sunnyvale, CA, United States of America

Charles William Russ, Iv