Loading patent…
AssigneeCoulston International Corporation
InventorsFriedhelm Korte, Ahmet H. Parlar, Frederick Coulston
Estimating the term…
A single-stage quadrupole mass analyzer is provided with a highly sensitive electron multiplier, a turbomolecular pump, and a mass correction lens placed between the quadrupole sensor unit and the turbomolecular pump. These components are arranged and selected to provide a substantial increase in sensitivity permitting the direct analysis of organic compounds in the gas phase in the ppb and high ppt concentration range. The placement of the mass correction lens and the area of its aperture has a pronounced effect on the detection limit, the optimum aperture area is a function of the mass of the molecules to be detected, and preferably an iris diaphragm is used to permit manual of automatic adjustment of the aperture area to a predetermined optimum for each of the different substances to be detected. Preferably the electron multiplier voltage is also variably selected and reset during the scanning of each fragment ion to optimize the signal-to-noise ratio of the electron mutiplier. The mass analyzer is sufficiently compact and economical to provide on-site analysis and the continuous monitoring or control of industrial processes.
A system for the analytical determination of organic substances in low concentrations by transferring the substances from a source at a relatively high pressure into a mass analyzer at a low pressure, said system comprising:
A system for the analytical determination of organic substances in low concentrations by transferring the substances from a source at relatively high pressure into the mass analyzer at a low pressure, said system comprising:
A method of using a quadrupole mass spectrometer for the analytic determination of organic substances in low concentration by the steps of (1) admitting a flow of said substances through a metering device to said mass spectrometer, (2) concurrently evacuating said spectrometer by a source of high vacuum, (3) placing a mass correction lens having an aperture in the flow of substances between the mass spectrometer and the source of vacuum, and (4) preselecting the area of said aperture to optimize the detection limit of a particular substance to be detected.
Dependencies are inferred from the claim text.