Hitachi, Ltd.

Yoshiaki Yamada

Hironori Kaji

Kiyotoshi Mori

Taro Nogami

Masato Fukuda

Sadabumi Ohnuma

Wataru Kato

Genzo Hirata

Sachio Tomimatsu

Hiromi Takiuchi

Shigeru Amiya

Synichi Mathuura

Yoshimi Sugiyama

A flow cell is provided with a cell body having an inlet flow passage, a detection flow passage, an outlet flow passage, and windows fixed to the cell body on both sides of the detection flow passage. The inlet flow passage is formed by inserting in and closely contacting a tube in and to a hole formed in the cell body, respectively.

Liquid chromatographic apparatus

A chromatograph is provided for accurately identifying components of a sample even with the use of a moving average method for noise reduction. A eluding solution is supplied to a column by a pump. In a sample injector, the sample injected into the column is separated into components by the column, and converted to an electric signal by a detector. A detected output signal is subjected to data processing in a data processor. The output signal is sampled at regular intervals and subjected to moving average processing in the detector. A sample injection signal from the sample injector is sent to the detector which generates a data processing start signal that is delayed by a time equal to a delay resulting from the moving average processing for the signal. The data processing start signal is sent to the data processor which starts the data processing in response to this signal.

Chromatograph

A reliable analytical apparatus is provided which can produce a highly reliable analytical Value on the basis of data entered during manual sample preparation which can be easily traced and used in editing of the analytical result of the analyzer because they are stored in association with the results of measurements by the analyzer. The analytical apparatus has an input device for inputting sample preparation procedures through the display screen, and various computations based on weighed quantities, constant dilution volume and so on entered during the manual preparation, which are automatically executed so as to eliminate human error.

Analytical apparatus, liquid chromatography analyzer and a method

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.

Apparatus and method for chromatographic analysis using pressure changes

An optical detector for flowing sample comprises a light condenser for condensing a diverging monochrome light, a flow cell arranged in the course of convergence of the converged light beam, and a sample-side detector for receiving a sample-side light. Such a construction makes it possible to correct delicate changes of the light axis due to intensity, position, temperature changes of the light source, density change of the flowing liquid, and any change of other causes effectively for stable sample analysis without difficult optical adjustment.

Optical detector for flowing sample and optical detection method for

The volume of the sample added to the sample retainer and the capacity of the sample retainer are compared, and the less one is stored as volume of the sample injected to a sample separating column. If the volume of the sample added to the sample retainer is more than the capacity of the sample retainer, accordingly, the capacity of the sample retainer is stored.

Liquid chromatograph

A plunger pump for supplying solution in accordance with an extrusion action of a plunger within a pump chamber. The plunger pump includes a cleaning chamber sealed by a seal member around and relative to the plunger, with a cleaning liquid inlet-side flow conduit and a cleaning liquid outlet-side flow conduit for communicating with the cleaning chamber, respectively. A mechanism isolates one of the inlet- and outlet-side flow conduits from the atmosphere and releases the other to an atmosphere under a condition where the cleaning liquid inlet- or outlet-side flow conduits are filled with the cleaning liquid. If the seal member in sliding contact with the plunger is degraded or aged, it is possible to observe a leakage of the liquid from the pump chamber along a sealing face between the seal member and the plunger.

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Tsuchiura, Japan

Yoshiaki Yamada