Abstract: This invention relates to an apparatus for the selective determination of e concentration of a substance dissolved in a solvent by means of an osmosis cell. The osmosis cell according to the invention contains a substance not contained in the solution to be tested, which is either practically insoluble or is impermeable for the membrane. This substance reacts chemically with the substance permeating into the osmosis cell, with a product resulting from it in the cell or with a product resulting from the substance in the solution to be tested and permeating into the cell. Reaction products are thereby formed which produce a pressure in the osmosis cell, which is different from the osmotic pressure of the chemically converted portion of the substance. A pressure increase thereby occurs in the cell, from which the concentration of the substance in the solution to be tested can be determined on the basis of standard values.

Abstract: This invention relates to a process for the selective determination of the oncentration of a substance dissolved in a solvent by means of an osmosis cell. The osmosis cell according to the invention contains a substance not contained in the solution to be tested, which is either practically insoluble or is impermeable for the membrane. This substance reacts chemically with the substance permeating into the osmosis cell, with a product resulting from it in the cell or with a product resulting from the substance in the solution to be tested and permeating into the cell. Reaction products are thereby formed which produce a pressure in the osmosis cell, which is different from the osmotic pressure of the chemically converted portion of the substance. A pressure increase thereby occurs in the cell, from which the concentration of the substance in the solution to be tested can be determined on the basis of standard values.

Abstract: In a process for the determination of the concentration of a substance dissolved in a solvent by means of an osmometer, comprising a two-chamber system with a first chamber having an osmosis cell and a second chamber for the measurement solution, to shorten the measurement time and to improve the separation of permeating components during the measurement of the concentration of the substances in the measurement solution, the pressure in the osmosis cell is held constant with an incompressible membrane arrangement, whereby with a pressure measurement apparatus in the second chamber after the replacement of a solvent, a reference solution or a calibration solution by a measurement solution, a pressure curve which corresponds to the concentrations of the nonpermeating substance and permeating substances or to the flows of the permeating substances between the osmosis cell and the second chamber is measured, and by analysis of the curve, the concentration of the nonpermeating and permeating substances in the meas

Abstract: This invention relates to a process and apparatus for the determination of he concentration of substances dissolved in a solvent. For this purpose, an osmotic cell is used, in which first, by means of an (external) reference solution, a working pressure is established, and after replacement of the reference solution by the solution to be tested, the pressure curve established in the cell is determined. The object is also to determine the concentrations of substance present in high concentration with very great absolute precision. For this purpose, an osmometer solution is selected which contains an excess of not more than 80 mOsm more than the reference solution, and in which the substances to be measured are contained in such a concentration that the difference of the concentrations of the substances in the solution to be tested and in the osmometer solution is not more than 70 mOsm.

Abstract: The invention relates to methods for the determination of the concentration of substances dissolved in a solution by means of an osmotic cell, using a pressure measurement device, and an apparatus incorporating the aforesaid osmotic cell with pressure measurement device. According to a first method, the concentrations of the substances are determined by the formation of the differences between a final pressure which is established after contact with the solution and an original and minimum pressure. According to a second method, the pressure/time course of biphasic response curves is analyzed in the vicinity of the minimum pressure, along with the rate constant for the exponential pressure increase which takes place after the minimum pressure, and the concentrations of the substances are then computed.

Abstract: An apparatus for measuring the pressure in a very small volume, such as a ological cell or a capillary vessel. The apparatus has a space or chamber which is connected with a microcapillary tube, is pressure-tight, and is filled with a nearly incompressible medium, such as silicone oil or the like. To measure the pressure in the space, a device for converting the pressure into electrical values is connected to the space. A body, which partially displaces the medium and is moved from outside the space, extends into the space. The apparatus includes a reference electrode and another electrode which is arranged within the microcapillary tube and extends nearly to the opening of the tube. The two electrodes are electrically connected to a control device which is connected with a drive for moving the body which is provided for partial displacement of the medium.