Hitachi, Ltd.

Naoto Oki

Yasuhisa Shibata

Satoshi Ozawa

Hiroyuki Miyagi

Tomonori Mimura

Kyoko Imai

Isao Shindo

Kahei Shiraishi

Kenichi Takahashi

Before analysis, the correspondence between the vessel positions and the reaction vessels held in the vessel positions respectively at the time of completion of all the operations of a turntable upon completion of the last analysis are stored in a computer in advance. When a start switch is turned on, a judgment is made as to whether the correspondences between the vessel positions and the reaction vessels coincide with those stored in the computer or not. In the case of coincidence, reaction vessels in vessel positions are regarded as having been already cleaned, so that these reaction vessels are subjected to blank measurement and sample addition in the case of optical measurement, whereas these reaction vessels are directly subjected to sample addition in the case of ISE measurement.

Automatic analyzer having cuvette cleaning control device

An anion-selective electrode of the present invention comprises, as anion sensitive substance, a tetraalkyl type, quaternary phosphonium salt having four alkyl radicals, each having 8 to 24 carbon atoms; a combination of a tetraalkyl onium salt having four alkyl radicals each having 10 to 24 carbon atoms, and an onium salt having one alkyl radical with 1 to 20 carbon atoms and three alkyl radicals with the proviso that the number of carbon atoms contained in the three alkyl radicals each is larger than that contained in the one alkyl radical; or a tetraalkyl type, quaternary onium salt having an asymmetrical molecular structure. The anion-selective electrode has good properties including selectivity and measurement accuracy. An anion-selective, field effect transistor or a chemical analysis apparatus, provided with the anion-selective sensitive substance, is suitable for measuring an anion concentration with a high accuracy.

Anion-selective, sensitive film, electrode containing the same and the

The present invention provides an ion selective electrode for anions such as Cl.sup.- and cations such as Ca.sup.2+ which has a sensitive membrane comprising a polymer material and containing an ion sensitive material and a plasticizer. In thins ion selective electrode, the ion sensitive material is an ion exchanger such as a quaternary ammonium salt, a quaternary phosphonium salt or an organic phosphate and the plasticizer is a compound having the formula (1): ##STR1## wherein X represents an alkyl group, a phenyl group or a phenyl group to which a functional group bonds. As the plasticizer there may also be used a mixture of the compound of the formula (1) with an alcohol compound such as an alcohol having a dielectric constant of 10 or less and containing 10 or more carbon atoms or an ester compound.

Ion selective electrode

A calcium ion selective electrode having a sensitive membrane comprising an organic polymeric substance, a plasticizer and a calcium ion sensitive substance of neutral carrier type, wherein the dielectric constant of the plasticizer is 10 or less, thus remarkably improving the responsiveness and stability of the electrode.

Calcium ion selective electrode

A liquid film type, chloride ion-selective electrode is provided with the present invention, which comprises a sensitive film containing a polymeric material as a support film material, a tetraalkyl ammonium salt with four alkyl group each having 10-24 carbon atoms as a chloride ion-sensitive substance, and a mixture of a linear alcohol having a low dielectric constant with at leastg 10 carbon atoms and an organic compound having a dielectric constant higher than that of said linear alcohol as plasticizer. This electrode has a high selectivity over lipophilic anions and hydrophilic anions, high accuracy ion measurements, and a long life.

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Hitachi, Japan

Naoto Oki