The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 02, 1993
Filed:
Dec. 04, 1990
Ronald A Gatten, Pleasanton, CA (US);
Leslie A Miller, San Jose, CA (US);
Thomas J McCall, Jr, Fremont, CA (US);
Vance J Nau, Cupertino, CA (US);
Spectra-Physics, Inc., San Jose, CA (US);
Abstract
Methods and apparatus for effective vacuum degassing of a liquid are provided for liquid chromatography. The bottles with the liquid are mounted above the vacuum degassing unit to provide a head pressure to the LC pump and physical stability to the bottles. The liquid is heated in the vacuum chamber by a radiator of electromagnetic energy (in one embodiment, infra-red light). Alternatively the liquid is heated before it enters the vacuum chamber. The liquid is in an agitated state in the vacuum chamber. In one variation, the liquid is conducted through the vacuum chamber through tubes wound around bobbins so as to expose a greater portion of the surface area of the tubes to vacuum. Circuitry stops the vacuum pump for a duration of a chromatographic run. The circuitry controls the LC pump and the vacuum pump so as to optimize the chromatographic conditions in the liquid chromatography analytical system. The autosampler of the analytical system includes a vacuum degasser for degassing the resident solvents of the autosampler. Alternatively, the vacuum degassing unit for degassing the mobile phase is used to degas the resident solvents. The analytical system has its own vacuum chamber for extracting a gas from the sample to be analyzed. The extracted gas is used to produce chromatographic information. Components of a mixed solvent are mixed before the solvent is degassed. The vacuum chamber of the degassing unit is used in one variation to dissolve a selected gas in a mobile phase for use in chromatographic analysis. A method is provided for testing a conduit for conducting a liquid through the vacuum chamber. A selected gas is put in the conduit instead of the solvent, a vacuum level is created, and the time of decay of the vacuum level is measured to determine the contamination of the walls of the conduit.