SU1306954A1 - Method of determining partial pressure of gases dissolved in fermentation solutions - Google Patents

Abstract

The invention relates to methods for analyzing fermentation media and can be used in the microbiological, medical and food industries. In order to increase the accuracy of determining the partial pressure of gases, an indifferent gas is introduced into the medium, its partial pressure in the gas phase is determined after establishing equilibrium in an indifferent gas between the medium and the gas phase. The permeability of the membrane for the studied gases is determined by the amount of the indifferent gas diffused through the gas-permeable membrane of the indifferent gas and its partial pressure, taking into account the properties of the membrane material and fermentation medium. By the number of test gases diffused through the membrane from the fermentation medium, taking into account the permeability of the membranes for them, the partial pressure of the test gases is determined. 1 il. a 9 (L with about 05 cond 4;

Description

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This invention relates to methods for analyzing fermentation media and can be used in the microbiological, food, medical and other industries.

The aim of the invention is to improve the accuracy of determining the partial pressure of gases dissolved in fermentation media.

The drawing shows a block diagram of a device that implements the proposed method.

The fermenter 1 has two identical diffusion sensors 2 and 3. Sensor 2 is installed in the gas phase above the fermentation medium, and sensor 3 is installed in the fermentation medium. The inputs of sensors 2 and 3 are connected via flow regulators 4 and 5, pressure regulator 6 with a source of carrier gas. The outputs of sensors 2 and 3 are connected to the distributor valve 7. One of the outputs of the latter is connected to the atmosphere, the other to the gas analyzer 8 connected to the information processing unit 9..

The method for determining the partial pressure of gases dissolved in fermentation media is carried out as follows.

The sample medium is aerated with a gas mixture with a constant content of an indifferent gas. Such a gas mixture can be air containing a constant amount of nitrogen.

The carrier gas through the pressure regulator 6 and the flow regulators 4 and 5 at constant values of pressure and flow enters the sensors 2 and 3. The gases in the gas phase above the fermentation medium diffuse through the gas-permeable membrane into the sensor 2, and The gases dissolved in the fermentation medium diffuse into the sensor 3. The diffused gases are carried by a flow of carrier gas through the distributor valve 7 to the gas analysis device 8.

In the first stroke, corresponding to the position I of the distributor valve 7, the gas mixture from the sensor 2 is analyzed and the partial pressure of the indifferent gas in the gas phase is measured, which at equilibrium between the analyzed medium and the gas phase above it is equal to the partial pressure of the indifferent gas analyzed medium.

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In the second stroke, corresponding to the position II of the distributor valve 7, the amount of gases diffusing from the analyzed medium through the gas-permeable membrane of the sensor 3 is measured. In block 9, the partial pressure of the indifferent gas measured by sensor 2 and the amount of indifferent gas 5 diffusing into the sensor 3 s measured by sensor 2 taking into account the properties of the material of the membrane and the fermentation medium for indifferent and test gases, the permeability of the membrane for the test gases and the values of The quality of the first gases diffused into sensor 3 of the first gases is determined by the state partial pressure in the medium being analyzed by the formula

- QS

where P is the pressure of the analyzed gas

in a fermentation medium; f is the amount of test gas diffusing through the membrane of pu 3 unit of time; 1 and S - thickness and area of the membrane

respectively; Q - membrane permeability for

researched .GS gas

calculated from the partial pressure of the indifferent gas, the amount of the indifferent gas; diffusing into sensor 3 taking into account the properties of the material of the membrane and the fermentation medium for an indifferent and test gas. ..

Thus, the method of intending the partial pressure of gases in fermentation media allows for increased accuracy in measurements in various media and under different hydrodynamic conditions.

Claims (1)

Invention Formula The method of determining the partial pressure of gases dissolved in fermentation media, which involves diffusion of gases from the analyzed medium through a gas-permeable membrane and measuring the amount of diffused gases, with t — distinguishing, in order to improve the accuracy, an environment-specific gas is introduced into the medium its partial pressure in the gas phase phase at the time of establishment of equilibrium indifferent gas between the medium and the gas phase and determine the permeability of the membrane for the gases being studied using the measured values of partial pressure and the amount of diffused indifferent gas with regard to the properties of the material of the membrane and the fermentation medium, and the partial pressures of the gases studied are determined by the number of gases that have diffused through the gas-permeable membrane, taking into account the permeabilities of the membrane. / & J 0 carrier