Agilent Technologies, Inc.

George E Yefchak

Carl A Myerholtz

Phillip W Barth

Gangqiang Li

Ganggiang Li

The present invention is directed to methods and apparatus for removing a gaseous bubble confined in a microvolume of liquid in a chamber. A source of liquid, a barrier region and an exit region are provided in fluid communication with the chamber. The source of liquid has an energy potential as regards movement of the gaseous bubble that is higher than the energy potential of the barrier region, the barrier region has a higher energy potential than the chamber, and the chamber has a higher energy potential than the exit region. The energy potential is reduced within the chamber, the source of liquid, the barrier region, and the exit region by an amount such that the energy within the gaseous bubble is sufficient to displace the gaseous bubble from the chamber through the barrier region and out the exit region and to fill the chamber with the liquid from the source.

Methods and apparatus for introducing liquids into microfluidic chambers

Adjustment systems, methods, computerized methods and computer readable-mediums that can be used in time-of-flight mass spectrometry (TOFMS) to account for thermal drift or mechanical strain are provided.

Thermal drift compensation to mass calibration in time-of-flight mass spectrometry

Method and apparatus for rapid monitoring of pressure in a chamber equipped with a mass spectrometer by using the primary beam current in conjunction with a conventional pressure gauge. The conventional gauge allows frequent calibration of the relationship of the beam current to the chamber pressure, preventing excessive drift in the system. An advantage of the system is that it takes advantage of instruments already present in a typical spectrometry apparatus.

Pressure measurement using ion beam current in a mass spectrometer

A method of providing an ion packet to an analyzer section of a mass spectrometer from an ion beam, a pulser which can execute such a method, and a mass spectrometer which includes such a pulser. In the method, a field pulse is applied to extract an ion packet from the beam at a sideways direction to the beam and provide it to a mass analyzer section of the mass spectrometer, which pulse simultaneously causes non-extracted ions of the beam to be deflected onto an electrode of opposite charge. The pulse ON time is significantly longer than conventionally used. For example, the pulse ON time may be longer than the pulse OFF time or at least twice as long as or several times longer than required to extract the ion packet and provide it to the mass analyzer section, so as to reduce stray ions entering the mass analyzer section. Preferably, the pulse ON time is the time required for ions of a predetermined highest mass of interest to be analyzed by the analyzer section, minus the time required to refill the region of the beam from which the ion packet is extracted with ions of the predetermined highest mass. Ion leakage into the mass spectrometer section between packet extractions, and hence detected noise, can be reduced.

Ion packet generation for mass spectrometer

A time-of-flight mass spectrometer includes a deflector and a filter assembly that is located along a flight path between the deflector and an ion detector. The filter assembly passes incoming ions to the detector when the ions approach the filter assembly along their original flight path, and the filter assembly occludes incoming ions from the detector when the ions have been deflected from their original flight path by the deflector. In an embodiment, the filter assembly includes filtering plates that are aligned such that the major surfaces of the filtering plates are parallel to the original flight path of the ions. In order to remove ions of a particular mass from a mass spectrum of ions, target ions are deflected from their original flight path, causing the target ions to impact the filtering plates while the ions that are not deflected from their original flight path pass between the filtering plates for measurement by the detector.

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Santa Clara, CA, United States of America

George E Yefchak