Abstract: Pipes provided with each switching valve in intermediate portions thereof for feeding sample solutions to a separation mechanism are joined by a multi-way joint, to reach the separation mechanism through a pump. When all valves are closed while driving the pump and thereafter one valve is opened, all bubbles etc. downstream the opened valve are swept and eliminated due to abrupt flow of a liquid since a portion downstream the valve has been decompressed. In switching of a sample in sample measurement, a valve of a pipe for a completely measured sample is left open while a valve of a pipe for a next sample is opened, and then the valve of the pipe for the previously completely measured sample is closed after a while. Thus, pressure fluctuation following sample switching is avoided.

Abstract: In a two-substrate measuring apparatus employing a first enzyme electrode for responding only to a first substrate to be measured and a second enzyme electrode for responding to both first and second substrates to be measured, in which the same enzymatic reactions are used for forming detectable substances and the substances to be finally detected by the electrodes are identical, when calculating the calibration curve for the second substrate to be measured, the output portion due to traces of the first substrate contained in the second substrate to be measured is removed, so that the second substrate is measured at a high sensitivity and high accuracy.

Abstract: The present invention relates to a simple and yet multifunctional system for assay employing immobilized enzymes.

Abstract: A method and apparatus for the determination of the average molecular weight, average chain length or dextrose equivalent of starch and related carbohydrates containing glucose units. The starch is analyzed by determining the free glucose amount (Gf) contained in starch or related carbohydrate sample, determining a gross glucose amount (Gt) rendered by hydrolysis of starch or related carbohydrates, and further determining a glucose amount (Gr) rendered by hydrolysis of a reduced product which is obtained by reduction of reducing terminals contained in starch or related carbohydrate.The average molecular weight, average chain length or dextrose equivalent of the starch is determined using the formulas stated below from the measured amounts of the free glucose amount (Gf), and the glucose amount (Gr).

Abstract: An electrode comprising an electrically conductive base, and a selectively permeable membrane which is produced by forming a membrane from a mixed solution comprising (a) albumin, (b) at least one type of crosslinking agent and (c) chitosan. The selectively permeable membrane is useful, e.g., in conjuction with an electrode. An enzyme electrode is also provided having the selectively permeable membrane disposed on the electrode and an immobilized enzyme membrane disposed on the selectively permeable membrane. The immobilized enzyme membrane is prepared by incorporating a carboxylate into the solution containing the enzyme and an aldehyde as the crosslinking agent. The crosslinking is effected by heating or drying.

Abstract: In the case of measuring concentration of, for example, glucose as a first substance to be measured, and that of sucrose as a second substance to be measured, using a measuring apparatus, the apparatus is provided with a first enzyme electrode, a dilution pipeline situated at the downstream of the electrode and for diluting the substances, and a second enzyme electrode situated at the downstream of the dilution pipeline. A sample, which contains the first and second substances, is poured intermittently into a constant flow of a buffer solution. The first enzyme electrode detects the first substance. The second enzyme electrode, which comprises an immobilized enzyme catalizing the conversion of the second substance in to the first substance, detects the first substance, which is originally contained in the sample as well as is formed on the second enzyme electrode.

Abstract: A liquid dilution system which dilutes a sample to be analyzed with a carrier to supply a diluted sample-containing liquid to an analytical measurement apparatus of flow type. The inventive dilution system features simplicity and versatility as compared to conventional automatic apparatus with robot concept, and the present system comprises: a first carrier pump for feeding a first carrier; a sample injection unit for injecting the sample into the first carrier; a main passage for flowing a liquid from the sample injection unit to a detector unit of an analytical measurement apparatus; a branching device located downstream of the sample injection unit for forming a branched passage to remove a liquid mass partially from the main passage; a confluence unit located downstream of the branching unit for confluencing a second carrier; and a second carrier pump for feeding the second carrier to the confluence unit.

Abstract: Alcohol oxidase is immobilized by bonding an aminosilane coupling agent to a carrier, bonding a multifunctional aldehyde such as glutaraldehyde to an amino group of the aminosilane, washing the carrier to remove free multifunctional aldehyde and bonding alcohol oxidase to the multifunctional aldehyde bonded to the aminosilane. Washing to remove free multifunctional aldehyde enables immobilizing a one molecule thickness of alcohol oxidase on the carrier since free multifunctional aldehyde is not present to cross-link alcohol oxidase molecules together. A thin layer of alcohol oxidase is advantageous when assaying for alcohol since a thin layer does not retain hydrogen peroxide that can deactivate alcohol oxidase. The carrier preferably contains hydroxyl groups and is porous, and can be a silicate-containing carrier such as diatomaceous earth or fire brick.

Abstract: An enzyme electrode possessing an immobilized enzyme membrane or an immobilized enzyme layer composed by applying a solution containing alcohol oxidase and a crosslinking agent, in which the solution further contains reduced glutathione.According to the invention it is possible to immobilize alcohol oxidase stably, and an excellent immobilized enzyme electrode for alcohol measurement is obtained. Furthermore, by this invention, a highly sensitive and stable measuring method is conducted quite easily.

Abstract: An enzyme electrode for measuring malto-oligosaccharides having a co-immobilized enzyme membrane containing glucoamylase and a glucose oxidizing enzyme such as glucose oxidase or pyranose oxidase.The glucoamylase and glucose oxidizing enzyme are immobilized at a ratio of ##EQU1## where Va is the maximum reaction rate of glucoamylase as expressed in the glucose formation rate from maltose, and Vo is the maximum reaction rate of glucose oxidizing enzyme as expressed in the hydrogen peroxide formation rate from glucose.In such enzyme electrode, malto-oligosaccharides are detected at the response value proportional to their degree of polymerization. Therefore, the malto-oligosaccharides can be measured at the glucose converted concentration.

Abstract: An enzyme electrode is prepared by a process wherein an albumin solution containing 0.05 to 0.5% by weight of a multifunctional aldehyde is applied onto the surface of an electroconductive substrate while maintaining the atmospheric temperature at 0.degree. to 20.degree. C. to thereby form a crosslinked albumin layer on the surface of the electroconductive substrate. Thereafter a solution containing 0.5% by weight or less of a multifunctional aldehyde and a predetermined amount of an oxidase capable of producing hydrogen peroxide (H.sub.2 O.sub.2) is applied on the surface of the previously formed crosslinked albumin layer to form a H.sub.2 O.sub.2 productive oxidase containing layer.