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:
Nov. 06, 1990
Filed:
Sep. 18, 1989
David J Miller, Grand Forks, ND (US);
Steven B Hawthorne, Grand Forks, ND (US);
UND-SEM Foundation, Grand Forks, ND (US);
Abstract
An injector for use with a capillary supercritical fluid chromatography (SFC) apparatus includes an operable four-port switching valve having a body portion and a rotor rotatably mounted within the body portion. The rotor has a hole therethrough which will selectively register with pairs of aligned ports. Thus, the rotor is rotatable between a loading position, wherein a first and third port are in communication, and a chromatographic position, wherein a second and fourth port are in communication. A first tubular member extends from the third port and is connected to a retention gap, which is in turn connected to an end of a capillary SFC column. A bypass tube connects the fourth port to the first tubular member. The loading position of the rotor and the first tubular member form a straight pathway to permit a needle to be inserted therethrough into the retention gap to inject a sample. A method is also disclosed whereby said injector permits the venting of a sample solvent from the injector by cycling the rotor, between the chromatographic and loading positions for predetermined time intervals.