RU2783062C1 - Apparatus for determining the odour intensity of water - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to analytical chemistry and is intended to determine the odour intensity of water. Apparatus for determining the odour intensity of water includes a sorbent-modified piezoelectric sensor secured in the removable cover of the detection cell made in the form of a cylinder with a level mark for the analysed liquid; apparatuses for exciting oscillations of the piezoelectric sensor and measuring the speed of oscillation of the piezoelectric sensor and discrete information display; and a battery, wherein a piezoelectric sensor modified by a universal sorbent is applied; the detection cell is equipped with a thermostat with a regulator, a liquid temperature meter, and an additional cover; information is displayed on an electronic panel in the form of a numerical value of the analytical signal, compared to the continuous scale of the water odour intensity pre-built based on standard solutions.

EFFECT: odour intensity of water determined accurately at various temperatures.

1 cl, 2 dwg

Description

The invention relates to analytical chemistry and is intended to determine the intensity of the smell of water using a piezosensor gas analyzer.

The intensity of the smell of water is determined by the organoleptic method at temperatures of 20 ± 2 and 60 ± 5 ° C on a five-point scale according to GOST [GOST R 57164-2016. National standard of the Russian Federation. Drinking water. Methods for determining odor, taste and turbidity. Date of introduction: 01/01/2018]. The disadvantage of the existing approach to determining the intensity of the smell of water is the low accuracy of the analysis due to the influence of the subjective factor on the results of the study (the emotional and physical state of the taster, his qualifications, etc.), as well as the low resolution of the rating scale, which is discrete and includes 5 ranks.

The closest in technical essence and the achieved effect to the claimed one is a device for express analysis of the quality of products, including a piezosensor modified with a sorbent, fixed in a removable cover of the detection cell, which is made in the form of a cylinder with a level mark of the analyzed liquid, a device for excitation of oscillations of the piezosensor, measuring speed oscillation frequency of the piezoelectric sensor and discrete display of information, battery [RU 2634803 C. Device for express analysis of product quality / Kuchmenko T.A., Kochetova Zh.Yu., Drozdova E.V. et al. Appl. 05/24/2016. Published 11/03/2017 - prototype].

The disadvantages of the existing device are:

- it is impossible to determine in total the volatile components of the test liquid, which form the smell of water, since the piezosensor is modified by a sorbent that exhibits a high affinity for individual volatile components of the test liquid or for a group of related compounds;

- it is impossible to determine the intensity of the smell of water at different temperatures, as required by GOST R 57164-2016;

- low accuracy due to discrete display of information (light signaling device).

The technical task of the invention is to accurately determine the intensity of the smell of water at different temperatures.

The technical task of the invention is achieved by the fact that the device for determining the intensity of the smell of water includes a piezosensor modified with a sorbent, fixed in a removable cover of the detection cell, which is made in the form of a cylinder with a level mark of the analyzed liquid, a device for excitation of piezosensor oscillations, measuring the speed of the piezosensor oscillation frequency and discrete display information, a battery, what is new is that a piezosensor modified with a universal sorbent is used, the detection cell is equipped with a thermostat with a regulator, a liquid temperature meter and an additional cover, an electronic display for displaying information in the form of a numerical value of the analytical signal, which is compared with the one built in advance using standard solutions continuous scale of water odor intensity.

The technical result of the invention is achieved by using a piezoelectric sensor modified with a universal sorbent, for example, multilayer carbon nanotubes [Kuchmenko T.A., Bodrenko E.V., Anokhina E.P. Express method for the analysis of strong alcoholic beverages by an array of piezosensors "electronic nose" // Analytics and control. 2017. Vol. 21. No. 3. S. 262-273]. Universal sorbents do not show an increased affinity for individual gases, but sorb them in total, which makes it possible to determine the entire spectrum of odor-forming water components. Equipping the detection cell with a thermostat with a regulator and a temperature meter, for example, Tektron-Bio brand [Official website of SIMAS. circulation thermostats. Access mode: www.simas.ru/products/microbiology/common/circlerm] allows you to measure the intensity of the odor of water at temperatures of 20 ± 0.2 and 60 ± 0.2 ° C, as required by standard methods for assessing water quality [GOST R 57164- 2016. National standard of the Russian Federation. Drinking water. Methods for determining odor, taste and turbidity. Date of introduction: 01/01/2018]. When water is heated (or cooled) in a thermostat to a predetermined temperature, the detection cell is closed with an additional lid to prevent active evaporation of volatile components before the water sample is analyzed. A digital display built into the body of the device allows you to read numerical information - the speed of the oscillation frequency of the piezoelectric sensor (analytical signal), which depends on the concentration of components in the gas phase of the analyzed liquid, as indicated in the prototype. The numerical value is compared with the pre-built functional dependence of the analytical signal on the intensity of the smell of water, while the intensity of the smell is estimated not by ranks, but with a higher resolution (for example, up to tenths). The dependences of the intensity of the smell of water on the analytical signal at temperatures of 20 ± 0.2 and 60 ± 0.2 ° C are built according to standard solutions, the preparation methods of which are indicated in GOST [GOST R 57164-2016. National standard of the Russian Federation. Drinking water. Methods for determining odor, taste and turbidity. Date of introduction: 01/01/2018].

The device for determining the intensity of the smell of water is shown in figure 1. It consists of a piezoelectric sensor 1 modified with a universal sorbent, fixed in a removable cover 2 of the detection cell 3 with a mark for monitoring the level of the analyzed water 4, a thermostat 5 with a regulator and a liquid temperature meter, in which the analyzed sample water in the detection cell with an additional cover 6 is maintained until the specified temperature is reached. The power supply 7 is connected to the excitation circuit of the oscillation frequency of the piezosensor 8, a device for measuring the speed of the oscillation frequency of the piezosensor 9 and a digital display 10. The analytical signal is compared with a pre-built continuous scale to assess the intensity of the smell of water 11 for the corresponding temperature.

The device for determining the intensity of the smell of water works as follows. In the detection cell 3 is placed the analyzed water sample 4 to the risks, as indicated in the prototype. The detection cell is closed with a lid 6 and placed in a thermostat 5 with a regulator and a temperature meter. On a thermostat, for example, brand Tektron-Bio [Official website of SIMAS. circulation thermostats. Access mode: www.simas.ru/products/microbiology/common/circlerm] set the target temperature for determining the intensity of the smell of water 20 ± 0.2 or 60 ± 0.2 ° C in accordance with GOST [GOST R 57164-2016. National standard of the Russian Federation. Drinking water. Methods for determining odor, taste and turbidity. Date of introduction: 01/01/2018]. The achievement of the set water temperature is judged by the temperature meter built into the thermostat. A piezosensor 1 modified with a universal sorbent is placed in the cover of the detection cell 2, a power supply 7 is connected to the excitation circuit of the oscillation frequency of the piezosensor 8, a device for measuring the speed of the oscillation frequency of the piezosensor 9 and a digital display 10. Then the cover of the detection cell 6 is quickly replaced with a cover with piezoelectric sensor 2. The measurements are carried out for 30 seconds, as indicated in the prototype. An analytical signal is read from the electronic display 10, equal, for example, to 1.2 Hz/s at a water temperature of 20 ± 0.2°C or 2.3 at a water temperature of 60 ± (), 2°C. Analytical signals are compared with continuous scales of water odor intensity 11 built in advance under the same conditions as the measurements. The procedure for preparing standard water solutions with different odor intensities is given in GOST [GOST R 57164-2016. National standard of the Russian Federation. Drinking water. Methods for determining odor, taste and turbidity. Date of introduction: 01/01/2018].

Examples of constructed continuous scales for determining the intensity of the smell of water are shown in figure 2, where line 1 and line 2 of the dependence of analytical signals (AC) on the intensity of the smell of water (1, point) at temperatures of 20 ± 0.2 ° C and 60 ± 0, respectively, 2°C; 1-5 - ranks of the intensity of the smell of water, the description of which is given in GOST [GOST R 57164-2016. National standard of the Russian Federation. Drinking water. Methods for determining odor, taste and turbidity. Date of introduction: 01/01/2018].

In accordance with the above example, the odor intensity values of the analyzed water are 2.9 (Fig. 2, line 1) and 3.8 (Fig. 2, line 2) points. On a discrete rating scale, the values of analytical signals obtained in the example correspond to ranks 2 (the smell is weak, not causing disapproval) and 3 (the smell is easily noticed and causes disapproving reviews) [GOST R 57164-2016. National standard of the Russian Federation. Drinking water. Methods for determining odor, taste and turbidity. Date of introduction: 01/01/2018].

The device for determining the intensity of the smell of water allows you to: determine in total the volatile components of the test liquid, which form the smell of water; determine the intensity of the smell of water at different temperatures, as required by GOST R 57164-2016; improve the accuracy of determining the intensity of the smell of water.

Claims (1)

A device for determining the intensity of water odor, including a piezosensor modified with a sorbent, fixed in a removable cover of the detection cell, which is made in the form of a cylinder with a level mark of the analyzed liquid, a device for excitation of oscillations of the piezosensor, measurement of the speed of the frequency of oscillations of the piezosensor and discrete display of information, a battery that differs By using a piezosensor modified with a universal sorbent, the detection cell is equipped with a thermostat with a regulator, a liquid temperature meter and an additional cover, the information is displayed on an electronic display in the form of a numerical value of the analytical signal, which is compared with a continuous scale of water odor intensity built in advance using standard solutions.

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