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:
Sep. 22, 1998
Filed:
Oct. 09, 1996
Yoshiaki Yamada, Ishioka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method for chromatographic analysis wherein an eluent is fed by a pump and a sample is injected into the eluent from a sample injector, while the composition of the eluent is changed over time. A mixture of the eluent and the sample is passed through a column, and identification of the sample is performed based on separation of the sample into components in the column. The pressure of the eluent in a feed path is detected, a pressure depending on the composition of the eluent is obtained as a reference and the detected pressure is compared with the obtained pressure. Such a comparison enables abnormality in an apparatus for liquid chromatographic analysis to be easily detected. The apparatus for carrying out the chromatographic analysis includes a pressure sensor for detecting the pressure of the eluent in a feed path, a pressure memory for storing the pressure values detected at certain time intervals from the start of measurement as a data file of pressure transition data for each sample, a selector for, when an unknown sample is measured, selecting the pressure transition data, which is to be compared as a reference, from data files store beforehand, and a comparator for comparing the pressure values of the unknown sample detected by the pressure sensor and the values of the pressure transition data selected by the selector and determining an agreement between both the values.