Hitachi, Ltd.

Kazuo Yasuda

Takehiko Kitamori

Yasushi Nomura

Masataka Koga

Haruo Fujimori

Tadafumi Kuroishi

Kazumichi Suzuki

Teruaki Kobayashi

Kenshi Sugahara

Kounosuke Oishi

Junji Mori

Michio Itoh

Daizo Tokinage

Mitsuyoshi Yuasa

By use of an excitation beam having a wavelength which is equal to, or close to, the sizes of particular particulate substances as the object of analysis, the particulate substances such as an immunoreaction product between an antigen and an antibody or between the antigen and a material supporting the antibody thereon are detected selectively. Very small particles having specific sizes such as rheumatuid factors, cancer specific antigens can be detected with high sensitivity.

Method and apparatus for detecting particular particulate substance

There is provided an atomic absorption spectrophotometer wherein a magnetic field having a suitable value is applied to a light source radiating the emission spectral light of the atom to be analyzed in the advance direction of the radiated light in order to cause the Zeeman effect so that the wavenumber of a component which is included in the spectra shifted in wavenumber and which is varied to have a smaller wavenumber may coincide with or approach the wavenumber whereat the absorption spectrum is maximized, thereby the sensitivity of the atomic absorption being raised, the linear region of the working curve being improved, and the emission spectral light being stabilized.

Atomic absorption spectrophotometer

In a flow injection analysis method of injecting a predetermined amount of a sample into a continuous flow of a carrier solution and introducing a reaction zone of the sample and the carrier solution into a flow cell, signals representative of the respective absorptions of the reaction zone for a plurality of wavelengths are produced when the reaction zone is passing through the flow cell. The signals are subjected to an at least two-wavelength processing or differentiation processing, thereby providing a desired absorbance of a substance of interest for analysis free of the influence of a ghost component.

Elimination of ghost component in flow injection analysis method

A liquid film type, anion-selective electrode of the present invention is suitable for measuring a chloride ion concentration of blood. A sensitive film contains a plurality of plasticizers having different dielectric constants, an anion-sensitive substance and a polymeric support material for supporting them. An appropriate content of o-nitrophenyloctylether having a high dielectric constant is 5-30% by weight, an appropriate content of n-tetradecyl alcohol having a low dielectric constant 5-40% by weight, and an appropriate content of dimethyldioctadecylammonium chloride as the anion-sensitive substance is 5-30% by weight. An electrode for measuring anions with such a sensitive film has less adverse affect by protein on measurements. The sensitive film further containing n-dodecyl alcohol has a much smaller error of measurement.

Liquid film type, anion-selective electrode

A nephelometric immunoassay and a nephelometer therefore, characterized in that light is projected on a sample to-be-measured containing an antigen-antibody complex, that at least two light scattering intensities at different angles with respect to the incident light are measured, and that a true antigen concentration is discriminated by comparing the light scattering intensities.

Nephelometric immunoassay and nephelometer

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Katsuta, Japan

Kazuo Yasuda