SU1000472A1 - Apparatus for applying substances to base for studies - Google Patents

Description

(54) DEVICE FOR APPLYING THE STUDIED SUBSTANCES TO THE MATRIX

one

The invention relates to a technique for monitoring the content of trace elements in solutions, in particular, to devices for pre-concentration of the test substances on a matrix from aqueous solutions for subsequent analysis by a spectrometric method.

A device for applying the test substances from aqueous solutions to a cellulosic matrix impregnated with ion exchange resins is known, comprising a filtration apparatus consisting of a funnel with a matrix holder, the cellulosic matrix itself, and a pressure cylinder. Concentration on this device is carried out by passing aqueous solutions containing detectable ions through the cellulose matrix 1.

The drawbacks of the device are the duration of the filtration process of the aqueous solution through the matrix, the complication of the filtration process of large volumes of aqueous solution by partial leaching of the ion exchange resin from the matrix surface, which leads to an underestimation of the results of the analysis. In addition, the presence in aqueous solutions of solid mechanical impurities leads

to clogging the pores of the matrix, which causes an additional consumption of time for analysis.

A device is known for applying the test substances to a matrix of aqueous 5 solutions, comprising a cylindrical body, two electrodes, a cellulosic matrix placed between them, one of the electrodes and the matrix being placed horizontally and parallel to each other.

The disadvantage of this device is the discrepancy between the area of the ion-exchange membrane in the device, i.e., the area of the end part of the electrode in the cell is significantly smaller than the area of the matrix, which eliminates the uniform distribution of the extracted element over its entire surface. This disadvantage leads to a significant decrease in the reproducibility of X-ray fluorescence determination. Due to the significant difference between the cross-sectional area of the solution column and the electrode area, only part of the test solution is in the interelectrode space and, despite the active movement of the solution, the maximum percentage of extraction (complete extraction) of elements on the matrix is achieved with long-term process management.

The purpose of the invention is the acceleration of the process and the uniform distribution of the test substance over the matrix.

The goal is achieved by the fact that in a device for applying the test substances to a matrix of aqueous solutions, including a cylindrical body, two electrodes, a cellulose matrix placed between them, a baffle, one of the electrodes and the matrix placed horizontally and parallel to each other, the other electrode flat and placed parallel to the matrix, the electrodes and the matrix are made with areas equal to the cross-sectional area of the housing.

FIG. 1 shows a diagram of the device; in fig. 2 - electro cell; in fig. 3 - electric holder.

The device for concentrating cations and anions from water solutions contains a thermostatically controlled vessel 1 with an electric holder 2, a source of DC power 3, an adjustable thermostat 4, a mechanical switch 5, a vessel 6 for the test solution, a voltmeter 7, an ammeter 8, a thermostated vessel 1 contains an ; 9, a mechanical baffle 5, an adjustable tap 10, nozzles 11 for sample introduction and 12 leads.

The holder 2 consists of a housing 13, a pressure plate 14, an electrode (cathode and anode) 15, a cellulose matrix 16 and contains openings 17 for air exhaust.

The holder 2 is connected to the top of the thermostatted vessel 1 through a conical connection.

The device works as follows.

The cellulose matrix 16 is inserted into the electric holder 2 and secured with a pressure washer 14 until firmly seated. The electric holder 2 prepared in this way is placed into the conical opening of the thermostatted vessel 1.

The test solution from the vessel 6 enters the thermostatically controlled vessel I through the inlet 11 until it is completely filled, as it is filled, the air from the vessel 1 leaves through the openings 17, the valve 10 is in the "Closed" position. Thermostat 4 thermostat vessel 1 to a constant temperature, then turn on the mechanical stirrer 5 and ensure uniform displacement of the solution.

After the temperature from the DC power supply 3 is stabilized, a voltage is applied to the electrodes 9 and 15 to create an electric field along the table of the test solution.

At the end of the procedure: a - the ions are removed from the solution; the broomstick 5 is turned off, the voltage is removed, and then the electrode holder 2 is removed from the vessel 1. Cellulose matrix 16 with the elements isolated on it and the excess filter paper is removed from the electric holder 2. The matrix prepared in this way is used to analyze elements by the X-ray fluorescence method.

The operation of the device is carried out in the temperature range of 20-65 ° C. The voltage value is selected in such a way as to ensure the quantitative extraction of ions of detectable elements on the cellulosic matrix 16.

The proposed device for concentrating cations and anions from aqueous solutions in combination with the X-ray fluorescence method of analysis significantly increases the rapidity of determination of trace amounts of ions. So, as with the use of the proposed device, the expressness of concentration and, accordingly, X-ray fluorescence analysis is increased 10-12 times (see table).

The device can be widely used in factory laboratories, industry institutes for serial analyzes of process and waste waters, electrolyte solutions, etc., where preliminary concentration of the detected ions is assumed to increase the sensitivity of the method.

The table presents the comparative characteristics of the prototype and the proposed device.

The ability of the device to quickly concentrate cations and anions on the matrix, as well as the independence of the stability of the selected substances on the matrix from the storage time, allows the proposed device to be used in a portable version for sampling in places remote from large laboratories, where delivery of cumbersome and expensive equipment is difficult. The device makes it easy to automate the process of continuous monitoring of metal impurities in process water and waste discharges. The ability of the device to extract metals (including noble ones) in an electric field from aqueous solutions allows it to be used in the chemical technology of these metals.

Claims (1)

1. US Patent No. 4080171, cl. G 01 N 21/00, published 1975. 2 USSR Author's Certificate No. 477738, cl. From 25 to 9/00, 1973. j 2 f2