California Institute of Technology

The United States of America As Represented by the Administrator of the

Other

Mahadeva P Sinha

Charles E Giffin

Mark Wadsworth

David D Norris

Albert D Tomassian

Sheldon K Friedlander

An electronic ion detection system which may detect low-energy charge particles such as ions from, for example, a mass spectrometer system. The capacitive sensors are located with two plates which are separated by an insulator. The ions which impinge on one of the plates cause charge to be created. That charge may be amplified and then handled by a charge mode amplifier such as a CCD sensor. That CCD sensor may operate using fill and spill operations.

Direct detection of low-energy charged particles using metal oxide semiconductor circuitry

Temperature compensation for a magnetic sector used in mass spectrometry. A high temperature dependant magnetic sector is used. This magnetic sector is compensated by a magnetic shunt that has opposite temperature characteristics to those of the magnet.

Temperature compensation for miniaturized magnetic sector

An electrostatic sector device for a mass spectrometer is formed from a single piece of machinable ceramic. The machined ceramic is coated with a nickel coating, and a notch is etched in the nickel coating to form two separated portions. The sector can be covered by a cover formed from a separate piece of machined ceramic.

Machined electrostatic sector for mass spectrometer

Improvements to reduce the size of a GCMS while improving its performance. A first improvement adjusts the magnet for radii of travel. Another feature removes a portion of the magnet to compensate for the fringe field. Yet another improvement shaves portions off of the yoke near where they meet the pole pieces.

GCMS weight reduction techniques

Improvements for viewing particles, e.g. electrons or ions, in mass spectrometer systems. A special kind of system allows a phosphor to be formed which does not include any kind of conductive layer thereon. The particles impinge directly on the phosphor, and produce light that shines through an ITO layer. This special system enables lower voltage, and smaller systems. Another improvement enables direct viewing of ions from the system.

Array detectors for simultaneous measurement of ions in mass spectrometry

Organic and inorganic contaminants of an environmental sample are analyzed by the same GC-MS instrument by adding an oxidizing agent to the sample to oxidize metal or metal compounds to form metal ions. The metal ions are converted to chelate complexes and the chelate complexes are extracted into a supercritical fluid such as CO.sub.2. The metal chelate extract after flowing through a restrictor tube is directly injected into the ionization chamber of a mass spectrometer, preferably containing a refractory metal filament such as rhenium to fragment the complex to release metal ions which are detected. This provides a fast, economical method for the analysis of metal contaminants in a sample and can be automated. An organic extract of the sample in conventional or supercritical fluid solvents can be detected in the same mass spectrometer, preferably after separation in a supercritical fluid chromatograph.

Analysis of supercritical-extracted chelated metal ions from mixed

A magnetic sector for a non-scanning mass spectrometer includes a high permeability yoke with opposing faces to which are attached high energy product magnets and shaped pole pieces separated by a gap so that a high magnetic flux exists in the gap. The high magnetic flux in the gap enables very small surface areas of the pole pices faces forming the gap so that the overall magetic sector volume and weight are reduced.

Miniaturized lightweight magnetic sector for a field-portable mass

A system is provided for analyzing the particles in aerosols, as in making air pollution studies, which enables the making of rapid chemical analyses of particles. The system includes an apparatus for producing a controlled stream of individual particles to be analyzed from an environment, and an apparatus for vaporizing and ionizing the particles while they move in free flight, for analysis by a mass spectrometer. The apparatus for producing a stream of particles includes a capillary tube through which the air with suspended particles moves, a skimmer device having a small opening spaced from an end of the capillary tube to receive particles passing through the tube, and a vacuum pump for pumping air out of the space between the tube and skimmer. The vacuum pump serves to remove much of the gas from around the particles, while also creating an inflow of air and particles through the capillary tube. The particles passing through the skimmer opening can be simultaneously vaporized and ionized while in free flight, by a laser beam of sufficient intensity that is directed across the path of the free flying particles.

Growing community of inventors

Temple City, CA, United States of America

Mahadeva P Sinha