Hitachi, Ltd.

Hitachi Instrument Engineering Co., Ltd.

Hitachi Instruments Engineering Co., Ltd.

Yoshio Fujii

Masahito Ito

Hiroshi Satake

Junkichi Miura

Kasumi Yoshida

Kimiyoshi Koda

Mitsuo Shimada

Shigeru Matsui

Masao Kamahori

Sadabumi Ohnuma

Mitsuo Ito

Koji Nishiwaki

Yoshihiko Suenaga

Hiroshi Inomata

Fuzio Yamada

Kohta Kimiyoshi

Yohei Takashima

Kouichi Tagami

Fuminori Umesato

Fuminori Umesato, Deceased

Toshihiko Sakaide

A method for analyzing a plurality of amino acids in a fluid sample by a user is provided comprising the steps of introducing the sample into a buffer solution, passing the sample in the buffer solution through a separation column and setting a lithium ion concentration in the buffer to no more than 0.3 mols/L up to a time before &#x3b2;-aminoisobutyric acid (&#x3b2;-AiBA) is eluted.

Computerized method and apparatus for analyzing amino acids

In order to suppress base line drift due to change in a light source and to start analysis with a short waiting time so as to improve quantitative accuracy of analysis, a detected signal in a measurement wavelength and a detected signal in a reference wavelength are measured at each of arbitrary light intensity points by varying light intensity of a light source, and the corresponding relationship between the wavelengths is stored. An incident light intensity of the measurement wavelength is estimated from a detected signal in the reference wavelength based on the stored data.

Absorptivity detecting apparatus, chromatographic apparatus, method of

A liquid chromatograph and chromatography which can perform analysis at a higher speed with clearer separation between peaks. The liquid chromatograph comprises a separation column (10), a buffer pump (7) for feeding a plurality of buffers 1, 2, 3 and 4 into the separation column (10), a sampler (9) disposed in a flow path between the buffer pump (7) and the separation column (10) for introducing a sample to be analyzed into the flow path, and a reaction coil (14) for mixing and then reacting amino acids separated by the separation column (10) with a ninhydrin reagent. The separation column is sized so that a ratio (L1/R) of its length L1 to its inner diameter R is not more than 10. The particle size of an ion exchange resin filled in the separation column (10) is selected to be not more than 4 .mu.m.

Liquid chromatograph and liquid chromatography

A reference sample having a known concentration is injected into a chromatograph system before an unknown sample is analyzed. This is for the purpose of checking the deterioration of system performance or in other words for the purpose of checking system suitability. In the present invention, the chromatographic characteristic of the check sample at the time of deterioration of the system suitability is expected and stored in a memory in advance to be related to factors of deterioration of system suitability. A factor of deterioration is deduced by comparison between the actually analyzed chromatographic characteristic of the check sample and the relational data stored in the memory. A guidance required for removing the factor is displayed. Disclosed are preferred embodiments of a chromatograph system suitable for analyzing catecholamine or glycated hemoglobin.

Chromatograph system and method for maintaining system suitability

A method and an instrument for separating and analyzing a very small quantity of constituents to be inspected contained in an analyte such as a class of catecholamines by liquid chromatography after labeling. The entire processes of analytical operations include principally three processes, a preparing process, an impurity elimination process and a separation process. When one sample is perceived, the sample is processed in these three processes. In this case, while one sample is being processed in an impurity elimination process, a sample preceeding the one sample is processed in a separation process, and a succeeding sample is processed in a preparing process. In other words, these three processes are performed essentially in parallel. With this, it is possible to remarkably reduce analysis time as compared with individual single sample analysis.

Analytical method and instrument for analysis of liquid sample by liquid

A chromatograph system with improved automation is provided. In the chromatograph system of one embodiment, a regression line is set between retention times of predetermined peaks measured at each run in the past for a standard sample having known components. Referring to this regression line, the peak identifying condition, i.e., time window, is corrected. In another embodiment, there is provided a chromatograph apparatus having a function of estimating a limited life time of a system component. The analyzed results of the chromatograph system can thus be improved.

Chromatograph system and method of use

The present invention relates to a chromatography analysis method and a system employing the same which are capable of automatically determining an constituents to be detected contained in the unknown sample based on results on measuring a standard sample. The standard sample is first separated to obtain its chromatogram. The system extracts the necessary information from the chromatogram to identify the peaks corresponding to the constituents to be detected to set widths of time windows for the peaks. Then, the time windows thus set are applied to the chromatograms obtained by the separation of the unknown sample to identify the constituents contained in the unknown sample. By employing the present invention, it is unnecessary for an operator to input the retention time of each constituent to the system.

Method of and apparatus for performing chromatography analysis of

Physiologically active substances contained in a biological sample not subjected to deproteinization can be converted to their derivatives at a high efficiency without being adversely affected by the protein present in the sample, and accordingly the analysis of said physiologically active substances in the form of said derivatives can be performed at a high precision.

Liquid chromatographic method and apparatus for analyzing biological

The present invention provides a liquid chromatographic analyzer for analyzing a sample containing components for analysis by reacting the sample with a pre-labeling reagent to obtain a reaction mixture containing labeled components, concentrating the reaction mixture and separating the labeled components from each other, and detecting the separated labeled components by a detector, the steps of analysis being controlled to concurrently proceed by a control unit, thereby shortening the time for analysis per sample which analyzer includes: (a) a unit for storing samples containing components for analysis and a pre-labeling reagent for the components at a constant temperature, (b) a unit for reacting the sample with the pre-labeling reagent at a constant temperature to obtain a reaction mixture containing labeled components, (c) a unit for transferring one of the samples and the pre-labeling reagent from unit (a) to unit (b), (d) a unit for concentrating the reaction mixture and separating the labeled components from each other, (e) a unit for detecting the separated labeled components, and (f) a unit for controlling the steps of analysis to concurrently proceed, thereby shortening the time for analysis per sample.

Liquid chromatographic analyzer, sample feeder and prelabeling reaction

A method for analyzing amino acids in biological liquids wherein a buffer liquid including unknown components to be analyzed is introduced to a separation column for separating amino acids. After reaction of the buffer liquid in a reactor, the amino acids are detected by a photometer. The flow rate of the buffer liquid is maintained at a predetermined value until the asparagine, glutamine acid and glutamine are separated from the separation column and the flow rate of the buffer liquid is varied stepwise or in linear gradient after separation of the above three components from the separation column.

Method for analyzing amino acids and apparatus therefor

An analyzing apparatus is controlled by a microcomputer which reads out programmed information from a magnetic card. The magnetic card does not always travel at a constant speed, and therefore, it is difficult for the microcomputer to entirely resort to the software for carrying out the signal processing required for the control of the analyzing apparatus. In order to obviate this difficulty, a hard logic circuit is provided to read out inverted bit information from the magnetic card, and the information thus read out is supplied to the microcomputer so that the microcomputer can reliably carry out the processing steps including bit counting and data reception. The hard logic circuit includes a flip-flop storing an FM signal recorded on the magnetic card and an exclusive-OR gate comparing the flip-flop output with the FM signal. A simple logic circuit is also provided for writing the FM signal on the magnetic card.

Analyzing apparatus with microcomputer

A detecting device is disposed between a separation column to which an eluent is supplied and a flow passage resisting member is located in a flow passage leading to a liquid discharge exit. This detecting device includes a sample cell and a reference cell. The effluent from the separation column is introduced into the flow passage resisting member through the sample cell. A change-over valve is disposed in the flow passage between the separation column and the sample cell and also is connected to one end of the reference cell. The other end of the reference cell is connected to the flow passage between the sample cell and the flow passage resisting member, whereby the reference cell and sample cell are kept communicated with each other. After an eluent has been filled in the reference cell, the communication of the flow passage between the separation column and the sample cell with the reference cell is intercepted by the change-over valve. While this interception is maintained, an effluent from the separation column is passed through the sample cell, and concentrations of respective components in the sample solution are measured by comparing the sample solution with the reference solution in the reference cell with respect to the refractive index or absorbance. Since the noise and drift can be reduced according to this system, the measurement accuracy can be highly improved.

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Katsuta, Japan

Yoshio Fujii