Fuji Photo Film Company, Limited

Fujifilm Corporation

Fuji Shashin Film Kabushiki Kaisha

Masaaki Terashima

Osamu Seshimoto

Yoshio Saito

Harumi Katsuyama

Yoshikazu Amano

Teruaki Koizumi

Hajime Makiuchi

Kenji Arai

Toshihisa Ito

Yoshiyuki Doi

Mituharu Nirasawa

An object of the present invention is to suppress an electric potential drift as described above and improve pH measurement precision in order to obtain practical measurement precision in the dry-type multilayered film-type pH electrode. The present invention provides a complex pH electrode which has at least two ion-selective electrodes comprising a non-conductive support, a pair of electrode layers, an electrolytic layer and an ion-selective membrane where at least one of the ion-selective electrode is a hydrogen ion-selective electrode, wherein the hydrogen ion-selective membrane is saturated with carbon dioxide gas.

PH electrode

An ion selective monoelectrode complex which is favorably employable to manufacture an ion activity measuring apparatus, has on a common non-electroconductive support sheet, plural ion selective monoelectrodes each of which is composed of an electrode composite consisting of, in order, a silver metal layer, a silver halide layer, an electrolytic material layer, and an ion selective membrane, and an electroconductive terminal which is electrically connected to the silver metal layer and which has an exposed surface, under the condition that the ion selective monoelectrodes are aligned, without electric contact with each other, along an imaginary line bridging the electrode composite and the electroconductive terminal.

Ion selective monoelectrode complex

A device for measuring ionic activity is composed of:

Device for measuring ionic activities

A composite ion selective electrode comprising a calcium ion selective electrode member and a hydrogen ion selective electrode member which is characterized in that a calcium ion selective membrane of the calcium ion selective electrode member has a thickness of 5 to 30 &mgr;m, and the hydrogen ion selective membrane of the hydrogen ion selective electrode member contains tri-n-dodecyl-amine and trisethylhexyl trimellitate. Each of the calcium ion selective electrode member and the hydrogen ion selective electrode member can be employed singly.

Ion selective electrode

In the manufacture of an ion selective electrode composed of a non-electroconductive support, a pair of electrodes each of which has a silver metal layer and a silver halide layer, an electrolytic material layer, an ion selective membrane, and a non-electroconductive sheet having a pair of openings for receiving a sample solution and a reference solution, respectively, and having thereon a bridge member for electrically connecting the sample solution received in one opening and the reference solution received in another opening, the ion selective membrane is advantageously divided into two separate portions, one of which is placed in a position above one electrode and another of which is placed in a position above another electrode.

A silver/silver halide electrode composed of a non-electroconductive support sheet, a silver metal layer and a silver halide layer in order, is improved in its sensitivity by making the silver halide layer almost free from heavy metal element, for instance, by oxidizing the silver metal layer on its surface side with an oxidizing compound containing no heavy metal element or a chelated ferric oxidizing compound in the presence of a halide containing no heavy metal element.

Method for producing a silver/silver halide electrode and ion-selective electrode element

An aqueous dispersion used for control or calibration of a dry analysis element comprising at least one color producing reagent and a porous layer, which comprises water-insoluble liquid particles having a mean particle size of from about 0.01 to about 10 .mu.m selected from the group consisting of phthalates, trimellitates, phosphates, benzoates, amides, phenols, aliphatic esters, hydrocarbons, halogenated hydrocarbons, adipates, sebacates and natural polymers dispersed therein and a substance which is the same as or similar to the analyte to be determined wherein said substance is selected from the group consisting of glucose, urea, uric acid, creatinine, bilirubin, hemoglobin, triolein, glycerine, cholesterol, triglyceride, (NH.sub.4).sub.2 SO.sub.4, NH.sub.4 Cl, CaCl.sub.2, Ca(NO.sub.3).sub.2, MgCl.sub.2, NaCl, KCl, K.sub.2 HPO.sub.4, (NH.sub.4).sub.2 SO.sub.4, Ca(NO.sub.3).sub.2, and NaNO.sub.3.

Method for control or calibration in a chemical analytical determination

A plurality of dry chemical analysis films are stacked in a cartridge. A chemical analysis film supplier has a cartridge storage chamber in which a plurality of cartridges are stored so that the chemical analysis films in each cartridge can be taken out by a chemical analysis film removing device. In the the cartridge storage chamber, the cartridges are arranged in a circle, and a moisture-absorber holding portion is formed inside the circle of the cartridges, and a moisture absorber is loaded in the moisture-absorber holding portion.

Chemical analysis film supplier

An improved calibration method for calibrating the measured value of an analyte in a liquid sample by referring to a calibration curve drawn by plotting the interrelation between the calibration values of n (n is an integer of not less than 2) calibrators containing different contents of the analyte and the measured values of the analyte contained in respective calibrators. In the improved method provided by the invention, the function of the calibration curve is determined by a first step of estimating an imaginal point, the imaginal point either corresponding to a calibration value larger than the uppermost value of the n calibrators and vicinal to the upper limit of the determination range of the analyte or corresponding to a calibration value smaller than the lowermost value of the n calibrators and vicinal to the lower limit of the determination range of the analyte or a calibration value vicinal to the zero value, and a second step of determining the function of the calibration curve by plotting the imaginal point with two to n measured values.

Method for correcting a calibration curve

A method for control or calibration in a chemical analytical determination using a dry analysis element comprising at least one color-producing reagent and a porous layer, wherein the method comprises applying an aqueous dispersion onto the porous layer and measuring the optical density of the color produced, wherein the aqueous dispersion comprises a substance which is the same as or similar to an analyte to be determined and water-insoluble particles dispersed therein, wherein the particles are particles of a homopolymer, a copolymer, phthalates, trimellitates, phosphates, benzoates, amides, phenols, aliphatic esters, hydrocarbons, halogenated hydrocarbons, adipates, sebacates and natural polymers.

A reference solution for measuring an ionic activity which is utilized at the time of measuring the activity of a particular ion in an aqueous solution by the differential method using ion-selective electrodes, which is characterized by containing the compound having the general formula (I), (II) or (III) and an electrolyte. ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represent hydrogen atom or a lower alkyl group, respectively, and at least, one or R.sub.3 and R.sub.4 is a lower alkyl group, and X represents chlorine atom or bromine atom, ##STR2## wherein R.sub.5 represents hydrogen atom or a lower alkyl group and A represents a hydrogen atom or a halogen atom, and ##STR3## wherein R.sub.6 represents a hydrogne atom or a lower alkyl group. The reference solution of the invention may be preserved for a long period at room temperature without putrifaction, and the compound (I), (II) or (III) in the reference solution does not or scarcely influence upon the potential difference generated in the ion-selective electrode.

Reference solution for measuring ionic activity

In a device for measuring ion activity in a liquid sample such as a body fluid comprising at least one pair of ion-selective electrodes selectively responsive to a specific ion, a porous liquid distributing member for feeding a liquid sample to one electrode of the pair of electrodes, a porous liquid distributing member for feeding a reference liquid to another electrode of the pair of electrodes and a porous bridge for electrically connecting both liquids to each other, the improvement wherein the liquid distributing members are made of a nonwoven fabric composed of cellulosic long fibers.

Device for measuring ion activity

In a method of measuring ion activity of a liquid sample comprising steps of spotting a reference liquid and the liquid sample on surfaces of ion-selective membranes, respectively, of at least a pair of ion-selective electrode sheets which is electrically insulated from each other, said ion-selective membranes being provided on the top of said ion-selective electrode sheets; and measuring a potential difference between the ion-selective electrodes under the conditions that both liquids are electrically connected to each other by a bridge, the improvement wherein:

Method and device of measuring ion activity

An apparatus for measuring ionic activity has a nozzle connected to a reservoir containing a reference solution. The reference solution is pumped up from the reservoir without coming into contact with air, so as to be quantitatively dripped through the nozzle when a slide-type ionic activity measuring device is located at a position below the nozzle. After the reference and sample solutions are spotted on the ionic activity measuring device, at least one pair of probes comes into contact with the device so as to measure potential difference corresponding to ionic activity difference of at least one ion between the reference and sample solutions.

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Saitama, Japan

Masaaki Terashima