Hitachi, Ltd.

Mamoru Taki

Yoshio Watanabe

Junkichi Miura

Masao Kamahori

Hiroyuki Miyagi

Yoshinori Takata

Yuji Miyahara

Satoshi Ozawa

Koutarou Yamashita

Seiji Takeuchi

Taro Nogami

Kazunori Fujita

Masafumi Kanetomo

Yasuhide Matsumura

Toshiko Fujii

Yoshimasa Hamano

An ion sensor having an ion selectivity, which comprises an internal electrode of metal/metal salt, composed of an electroconductive layer of at least one metal and a layer of an insoluble salt of the metal in contact with the electroconductive layer, an ion selective membrane whose supporting membrane is composed of a hydrophobic polymer, and an intermediate layer capable of keeping water molecules, provided between the internal solid electrode and the ion selective membrane, where the organic compound having a water-keeping property is polymethylene glycol, polyethylene glycol or polypropylene glycol, each having a molecular weight of 200 to 600, and the inorganic compound having a water-keeping property is calcium chloride, gold chloride, magnesium perchlorate, magnesium fluoride or vanadium chloride dioxide, is suitable for analysis of specific ion species in a biological fluid with practically prolonged maintenance of properties of electrode.

Ion sensor

An ion-selective electrode comprises an ion-sensing membrane, an internal electrode adhered to the ion-sensing membrane, and a lead connected to said internal electrode. The internal electrode used comprises a plurality of metallic wires arranged into a grating or a mesh. The wires comprises a metal core and a surface layer of a salt of the metal. The metal of the core is silver and the salt of the metal is a silver halide selected from the group consisting of silver bromide, silver chloride and silver iodide. At least a part of the internal electrode is buried inside the ion-sensing membrane. Various components, the ion-sensing membrane, the internal electrode, the lead, an external terminal, are disposed in a flow-through cell having a flow path formed therein, through which path a sample solution is passed, to constitute the ion-selective electrode. In the flow-through cell is disposed a means of maintaining the humidity to feed water vapor therefrom to the ion-sensing membrane. This structure, even when the ion-sensing membrane has a complicated configuration such as concave or convex surface, enables the establishment of good adhering conditions between the internal electrode and the ion-sensing membrane while retaining the complicated configuration of the ion-sensing membrane without reducing the effective contact areas of the ion-sensing membrane and the internal electrode.

Ion-selective electrode

Catecholamines in a living body fluid are analyzed by a process which involves reacting a living body fluid sample with a boron compound of the formula: ##STR1## wherein R is hydroxyl, aryl or alkyl, to form a complex of the boron compound with a catecholamine; deproteinizing the reaction solution containing the complex; decomposing the complex to release the catecholamine; labeling the released catecholamine to form a labeled catecholamine; eluting the labeled catecholamine adsorbed on a separation column; and detecting the eluted, labeled catecholamine. Advantageously, this process enables catecholamines to be measured with a high recovery ratio and high accuracy by forming the catecholamines into a complex with a boron compound.

Method for analysis of catecholamine

Catecholamines can be detected with high sensitivity in a shortened time period, by introducing a sample containing catecholamines into an adsorption column packed with an adsorbent to adsorb catecholamines to the column, then introducing a reagent for derivatization to effect pre-column labeling and then analyzing the pre-column labeled catecholamines by means of high performance liquid chromatography. Connection of the adsorption column and a separation column of high performance liquid chromatography via a fluid path changeover valve enables to automated analysis of catecholamines.

Method for biochemical assay and an analyzer for the method

An autosampler consists of a needle to draw specimen from a specimen container into a passage therein; a block having a passage that follows the passge in the needle; a suction mechanism for drawing in the specimen by suction through the passages in the needle and the block; a discharge mechanism for discarding the specimen drawn in by the suction mechanism; and a detecting device for detecting air bubble in the specimen, the detecting device being embedded in the block in such a manner as to face the passage in the block. The detecting device detects the air bubbles in the specimen according to changes in physical or chemical properties of the specimen passing through the passage in the block. The discharge mechanism is activated by the detecting device to discharge air-mixed specimen. When even a small amount of air is drawn into the passage from the specimen container, in which only a small amount of specimen is contained, the air specimen can reliably be distinguished from normal specimen by this autosampler. Therefore the reliability of the system using the autosampler can be significantly improved.

Autosampler with a means for detecting air bubble in specimen

A flow cell for a photometer, which comprises a cell body integrated from a pair of cell body members by joining, at least one of which is provided with a linear groove on the joining surface of the cell body member from one end to another to the full length, as exposed to the joining surface, the groove playing both roles of a liquid sample passage and a detecting light path by the integration of the cell body members, and is further provided with a liquid sample inlet passage at a position near one end of the groove and a liquid sample outlet passage at a position near the other end of the groove, both passages being communicated with the grooves, the linear groove being provided with a light reflecting layer to the full length of the linear groove, and a pair of light transmission window members joined with the flow cell body at both ends on the groove-open sides thereof is provided, where polishing of the grooves is readily carried out and random reflection of light or absorption of light due to poor reflection is reduced, and the turbulent flow of a liquid sample and generation of noise are suppressed.

Flow-through cell for a photometer formed using a pair of cell body

A sample leaving a separation column of liquid chromatograph is led to an electrolytic cell to obtain an electrolytic current corresponding to the amount of an assayed sample component. The electrolytic cell is divided into two compartments by an ion exchange pipe penetrating therethrough at the center. One compartment is a cylindrical working electrode chamber in the pipe, and the other compartment is a cylindrical chamber for a counterelectrode outside the pipe. A working electrode comprising a bundle of electroconductive carbon fibers is provided in the working electrode chamber, and preferably a swellable rod is inserted as a core into the working electrode. In the chamber for the counterelectrode, a cylindrical counterelectrode made of carbon fibers is provided to surround the outside surface of the ion exchange pipe. The inner diameter of the ion exchange pipe is substantially equal to the inner diameter of a tube for introducing the sample. The sample undergoes electrolysis reaction while the sample passes through the carbon fibers of the working electrode.

Flowthrough-type electrolytic cell

A disease diagnostic method and apparatus in which a two-dimensional pattern diagram representing the relation between integrated values of peaks and the retention times in a chromatogram of substances in a body fluid of a subject is obtained to be geographically compared, for disease diagnostic purpose, with a two-dimensional pattern diagram representing the relation between integrated values of peaks and the retention times in a chromatogram obtained through separating and detecting substances in a body fluid of a normal person, and also with two-dimensional pattern diagrams representing the relation between integrated values of peaks and the retention times in chromatograms obtained through separating and detecting substances in a body fluid of abnormal patients classified by diseases.

Method and apparatus for diagnosis of disease

A definite, but large amount of a sample solution is fed to a small concentration column filled with a packing material to retain in the concentration column components to be measured in the sample solution. Then, a small amount of a desorbing solution is fed to the concentration column to desorb the components retained in the concentration column. The effluent solution containing the desorbed components is fed to a separation column filled with a packing material. An eluting solution is fed to the separation column to separate the components from one another, and the components are detected by a detector. Since the components are separated from one another after their concentrations have been elevated, and thus the components can be measured with a high sensitivity.

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Ibaraki, Japan

Mamoru Taki