Radelkis Elektrokemiai Muszergyarto Szovetkezet

Magyar Tudomanyos Akademia

Egyt Gyogyszervegyeszeti Gyar

Radelkis Elektrokemial Muszergyarto Szovetkezet

Elektrokemial Muszergyarto Szov.

Radelkis Elektrokemiai Miszergyarto Szovetkezet

Jeno Havas

Erno Pungor

Geza Takacsi Nagy

Henrik Muller

Lajos Kecskes

Laszlo Toke

Istvan Bitter

Janos Daroczy

Erno Lindner

Bela Gai

Elek Doktor

Klara Szepesvary Nee Toth

Marton Patko

Emma Porjesz

Janos Erdelyi

Klara Toth

Zsofia Feher

Ferenc Takacs

Tamas Damokos

Katalin Nyiro

Maria Horvath

Maria Forro Nee Horvath

Denes Berky

The invention relates to new crown ether derivatives of the general Formula I ##STR1## and a process for the preparation thereof wherein Z.sup.1 is a group of the general Formula ##STR2## R.sub.a and R.sub.b may be the same or different and R.sub.a represents an alkyl group having 1-4 carbon atoms and R.sub.b is an alkyl group having 1-20 carbon atoms. The new crown ethers are useful in the preparation of ion-selective electrodes having a long lifetime.

New crown ether derivatives, process for the preparation thereof and

Crown ether compounds, process for the preparation of the crown ether

The present invention relates to electro-analytical measuring equipment for the determination--by means of one or more measuring cells comprising sensing elements of chemical similar composition, being in constant galvanic contact with each other--of the concentration and ion-activity of solutions or of the partial pressure of gases. The sensing elements are in contact with sample or with one or more standardizing media separated in time or space. At least two reference electrodes are in direct or in indirect contact--through electrolite--with sample and standardizing medium. The reference electrodes join, in a given case, to electronic signal processor comprising arithmetic unit calculating, by fault compensation, value of one or more parameters to be measured.

Electro-analytical measuring equipment with measuring cell, comprising

An electro-analytical measuring process and apparatus for the determination of the concentration and the ion-activity of stationary or flowing solutions or of the partial pressure of gases. The measuring cell of the measuring equipment--connected to an electronic signal processor--comprises, in addition to one or several sensing elements and reference electrodes, at least one fluid clutch capable of galvanically short-circuiting one or more parts of the measuring chain. The measuring cell of the measuring equipment comprises, in a given case, integral sensing unit and standardizing media, being in contact with sensing elements. Further, a control unit for programming short-circuiting belongs to the measuring cell, a fault compensating unit producing signals is connected to the control unit--for calculating the value of the parameter to be measured--is connected to the output of the fault compensating unit.

Fault-compensating electro-analytical measuring process and equipment

A molecule selective sensor having two permeable membranes in contacting relationship with each other, one membrane being a protein membrane found in nature, as for example, hog intestine membrane, air bladder of fish, epidermal section of mammals and reptiles, etc. and the other membrane being the reaction product of acrylamide, polyvinylalcohol, an enzyme, bovine albumin and glutaric aldehyde.

Molecule selective sensor for industrial use and procedure for its

A molecule selective sensor has an enzymatically active membrane which is prepared by reacting an enzyme with glutaric aldehyde on the surface of a protein membrane found in nature. Exemplary is the reaction of glucoseoxidase with glutaric aldehyde on the surface of hog intestine membrane.

Molecule selective enzyme electrode

The invention relates to a process of and equipment for a selective, quick and accurate analysis of liquid samples. According to the process of the invention a liquid or a gas sample absorbed by a liquid is allowed to flow at a constant volume rate and overtitrated with an amount of a reagent adequate to the measurement in a definite time. Then the flow of the reagent is decreased to zero in a definite time, meanwhile continuously following, in a known way, the changes occurring in the reaction mixture. The determination of the concentration is carried out by comparing the time elapsed between the appearances of the two chemical equivalence points with calibration curves prepared with standard solutions, said time having a well defined functional relationship with the concentration of the sample. The equipment according to the invention for carryinng out the process according to the invention contains an analysis channel in contact with a sample-storage tank or liquid storage tank or sampling device or liquid feeding device, said analysis channel comprising a gas-permeable membrane contacting a sample gas before the titration section if desired, said analysis channel being equipped with a pump, said analysis channel having a titration section comprising a small-volume flowthrough homogenizing space and a reagent feeder or reagent generator device coupled to a programming unit and joining said channel before the said homogenizing space. For the measurement and recording of changes occurring in time, said analysis channel has, in its section between said homogenizing space and the suitably shaped effluent section, a detector section containing one or more detectors and a recording and/or indicator unit; if desired, said analysis channel has an electronic signal processing unit coupled to the recording and/or indicator unit and to the programming unit. The accuracy of analyses carried out by the process and equipment according to the invention is identical with or higher than that of automatic titrators, and its velocity is identical with that of measurements carried out by flowthrough analysis channels, combining in this way all the advantages of both methods and measuring instruments.

Process of and equipment for the analysis of liquid samples by titration

Highly sensitive, selective halide and sulfide-sensitive electrodes featuring a sensing block of spherical surface and laminar design compensating for the effect of thermal dilatation and the absence of a liquid junction.

Selective halide and sulfide sensitive electrodes

The invention relates to coulometric measuring for the determination of the concentration and/or factor of acids or bases. A reference electrode and a measuring electrode sensitive to the activity of hydrogen ions of the indicator circuit and an anode and a cathode electrode of the generator circuit, are arranged in the measuring cell of the measuring apparatus. As a depolarizer and potential determining substance, the chloride, bromide or iodide of potassium, sodium, rubidium, cesium, calcium, strontium or barium is added in excess to the supporting electrolyte in the measuring cell. Inaccuracy and instability brought about by the diffusion potentials arising at the diaphragms can thus be eliminated.

Coulometric measuring method

A selective fluoride-sensitive electrode featuring a sensor block of spherical surface compensating the effect of thermodilatation and prepared from the fluorides of a lanthanide mixture corresponding to the composition of the natural occurrents or from a mixture composed of the majority of lanthanides.

Selective fluoride-sensitive electrode

Growing community of inventors

Budapest, Hungary

Jeno Havas