RU16791U1 - ELECTRODE SYSTEM FOR DETERMINING NITRATE ION ACTIVITY - Google Patents

Description

An electrode system for determining the activity of nitrate ions.

The utility model relates to devices for potentiometric analysis, namely to nitratomers and can be used to control the aquatic environments of food and fruit and vegetable products.

To determine the activity of nitrate ions, electrode systems complete with ionomers are used, including nitrate-selective electrodes paired with reference electrodes.

For this purpose, nitrate-selective electrodes, for example, EM-KOZ-01 (Analytical Systems), electrodes EMNO3-07 and EM-MOz-07 SR (Gomel measuring instruments factory), and reference electrodes, for example, EVL-electrode, were developed 1M4 (Gomel plant of measuring instruments). The electrodes are made as independent products in accordance with the relevant specifications.

For the prototype, a nitrate-selective EM-MOz-07 nitrate-selective electrode (TU RB 05796587.008-97) and a comparison electrode EVL-1M4 TU 25-05 (IE 2.840.517) -78 were selected.

A nitrate-selective electrode with a size of d 13x135 mm consists of a plastic case with a membrane, a silver-silver half-cell with a wire, and a rubber ring that provides tightness. 1.01 g of KKOz and 1.245 g of KC1 per 100 ml of distilled water are poured into the electrode housing.

G01N 27/30, 27/333

A similar device also has a reference electrode, into the body of which an electrolyte solution KC1 with a concentration of 250 g / l is washed down. Measurements and calibration are carried out by immersing the lower parts of the electrodes containing sensitive elements in a controlled or control solution.

The disadvantage of this and similar electrode systems is the need to prepare a water extract or grind fruit and vegetable products to obtain the required amount of a controlled sample, which is not always convenient.

The utility model solves the problem of developing a compact electrode system for the express method for measuring the activity of nitrate ions by applying sensitive elements of the electrode system to a wet cut of fruit and vegetable products or applying the test liquid in small quantities to sensitive elements.

The problem is solved by combining the indicator electrode and the reference electrode in one housing, while the contact surfaces of the sensitive elements of both electrodes are flat and brought to the same common area, and the reference electrode is filled with a gel-like electrolyte.

This solution makes it easier to work with the electrode system, reduces the amount of the test sample, and the presence of a gel-like electrolyte reduces the rate of flow of the electrolyte from the reference electrode and significantly reduces the degree of its influence on the sensitive element of the indicator electrode, which increases the accuracy when measuring low concentrations of nitrate ions and extends the life reference electrode.

The electrode system includes a plastic housing 1, in which the indicator electrode 2 is placed with a sensitive element nitrate-selective membrane 3 and the output to the recording system 4, the reference electrode 5, filled with saturated, thickened

polymer thickener, potassium chloride solution. The reference electrode 5 has a sensing element 6 and the output to the recording system 7. The electrode system contains seals 8, ensuring its tightness. Sensitive elements 3 and 6 are located on the common touch pad 9. The electrode system after calibrating the indicator electrode 2 relative to the reference electrode 5 and compiling the calibration graph works as follows: 2-3 drops of the test liquid, for example juice, are applied to the touch pad 9. In the presence of nitrates in the sample on the surface of the membrane 3, an exchange occurs between the ions of the membrane 4 by the nitrate ions of the sample, as a result of which a potential jump occurs and, according to the calibration graph entered into the microprocessor program of the recording system, the activity of nitrate ions or their concentration is determined.

The device is intended for laboratories in markets, fruit and vegetable bases, food processing plants.

Claims (1)

An electrode system for determining the nitrate ion, including electrodes with liquid internal filling — an indicator electrode and a reference electrode having sensing elements on the ends on the one hand and terminals for connecting to a recording system on the other, characterized in that the indicator electrode and electrode comparisons are placed in a single housing, while the reference electrode is filled with a gel-like electrolyte, and the contact surfaces of the sensitive elements are flat and located on a common platform.