RU2563836C1 - Use of aerosol spraying device for express detection of acidic aggressive chemicals on surface of objects - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: aerosol spraying device was used for indicator solutions spraying. An indicator formulation was sprayed over the tested surface, wherein the said formulation was sprayed in the form of a monodisperse aerosol at a distance of 10-15 cm, followed by a visual inspection of the indication effect. A 0.05-0.1% ethanol solution of mixed methyl red indicator and methyl yellow indicator at a ratio of 1:1 by volume was used for the detection of strong acids. A 0.05-0.1% solution of 4-diethyl-aminobenzene in ethanol was used for the detection of weak organic acids.

EFFECT: demonstrative indication effect, multiple usability and operability of the device within at least 2 years.

2 dwg

Description

The invention relates to the field of analytical chemistry, namely the use of a known device for a new purpose for the express detection of contamination of surfaces of objects with aggressive chemicals of an acidic nature.

The aggressive chemicals of an acidic nature include strong (sulfuric, nitric, hydrochloric and others) and weak (acetic and other) acids.

The need to use an aerosol device for the rapid detection of aggressive acidic chemicals on the surfaces of objects is due to the fact that the pouring of these chemicals can lead to chemical burns by working personnel, and the mixing of aggressive acidic and alkaline chemicals can cause severe smoke, explosions and fires . Therefore, the joint storage of these substances is unacceptable.

It is known to use an aerosol device for spraying drugs, varnishes, paints, emulsions. In recent years, many firms have offered aerosol packages that do not contain propellants. The content is dispensed by compressed air using a micropump (mechanical spray gun), which is screwed onto the neck of the cylinder and creates air pressure in the cylinder up to 5 atm. In such cases, a finely dispersed jet is obtained by combining the high hydraulic pressure developed by the pump with a small passage of the valve cross-section (using laser technology for this).

Currently, the cost of such packages is high and their use is not cost effective for all drugs. For spraying suspensions with a high content of solids, film-forming preparations, foams and other similar pumps are unsuitable.

The purpose of the aerosol, the state of the contents of the container, its consistency, composition and route of administration require the use of different, in each case, strictly defined types of valve spray systems. The valve of the aerosol package must ensure its tightness at a pressure in the cylinder up to 20 kgf / cm ² and evacuation of the drug from the cylinder. There are many designs of valve devices. They are classified according to three criteria: by the principle of action; according to the method of mounting on the container; by appointment.

According to the principle of action, they are classified into groups:

- spring, acting by pressing the spray head vertically down (spring, in turn, are divided into disposable and multiple; continuous and dosing);

- swinging springless, acting when you press the spray head on the side;

- valves with screw valve.

By the method of mounting on the cylinder:

- fixed in a standard cylinder opening by expanding the vertical walls of the valve body under the rim of the cylinder neck with a special collet device (for metal cylinders);

- fixed on the neck of the cylinder by rolling the valve body or capsule on special machines (for glass and plastic cylinders);

- valves screwed on the neck of the vessel (for large reusable cylinders).

By appointment:

- standard for liquid products; for foams; viscous products; powders and suspensions; special purpose valves; metering valves. The domestic industry produces four types of valves, nine types of nozzles and nozzles for them. They are divided into: nebulizers for inhalation; treatment of bronchial asthma; suspension and film-forming aerosols; dental, rectal, vaginal nozzles, etc. It is known to use an aerosol device for the express detection of polynitroaromatic explosives by applying an aerosol of an indicator formulation to the test surface with subsequent visual determination of the indication effect (RU 2369444). Indicator films, papers and tickets were previously used to detect acidic substances. In this case, to detect acidic substances, indicator papers and tickets must be brought into direct contact with the analyzed surface. If the operator works without gloves, this may result in him getting a chemical burn. If an aggressive chemical substance is absorbed into the paintwork, the sensitivity of the indicator paper to detect surface contamination is insufficient. In this case, the infection is determined only at the place of direct contact of the paper with the surface of the object with an area of about 10 cm ² . To detect the infection of a large-sized object, it is necessary to carry out such detection in several dozen of these areas. To eliminate these shortcomings, we propose the use of an aerosol device for detecting aggressive chemicals of an acidic nature.

The technical result of the invention is to increase the sensitivity of detection, speed, visibility of the indicator effect, ensuring safety and ease of use.

This technical result is achieved by the fact that it is proposed to use an aerosol device as an indicator for detecting aggressive acidic chemicals on the surfaces of objects, spraying indicator formulations onto the surface of an object is carried out using an aerosol device made in the form of a sealed enclosure filled with an indicator compound and a pump sprayer, while the presence of an aggressive chemical substance of an acidic nature is judged by the characteristic changing the color of the indicator on the surface of the test object in accordance with the standard on the label of the aerosol device, spraying the indicator formulation is carried out from a distance of 10-15 centimeters from the surface with a monodisperse aerosol, 0.05-0.1 wt.% solutions of a mixture of two are used to detect acidic substances indicators of methyl red and methyl yellow in a ratio of 1: 1 by volume in ethyl alcohol, to detect weak organic acids (acetic and others) use 0.05-0.1 wt.% solution of 4-diethylaminoazob benzene in ethyl alcohol.

To detect acidic substances, a method using indicator papers and tickets was previously used.

We have applied the method of aerosol spraying of the indicator formulation onto the test surface. In this case, the ability of the methyl red indicator was used to instantly change the color from yellow to red when changing from a neutral to an acidic medium (in the range of pH 4.4-6.2).

The methyl yellow indicator changes color from yellow to red in a more acidic pH range (2.9-4.0). Considering that both indicators equally change color from yellow to red in an acidic environment, in order to expand the range of determined products of an acidic nature, we recommended the use of a mixture of alcohol solutions of two indicators in a volume ratio of 1: 1.

Based on this, for the detection of acidic substances in our method, we use aerosol spraying of an indicator formulation, which is a mixture of two indicators of methyl red and methyl yellow in a volume ratio of 1: 1 in ethyl alcohol with a concentration of each indicator of 0.05-0.1 wt. % The use of a more diluted indicator solution leads to a deterioration in the sensitivity and visibility of the indicator effect. A more concentrated solution cannot be prepared due to the limited solubility of the indicators in the alcohol solution. In addition, the presence of a dark color in the indicator solution in this case masks the indication effect.

To increase the sensitivity, visibility and reliability of the detection of weak organic acids such as acetic acid, it is proposed to use a 0.05-0.1% solution of 4-diethylaminoazobenzene in ethyl alcohol as an indicator formulation of an aerosol device.

To obtain a visual indicator effect on the surface of objects using the proposed aerosol devices, it was necessary to ensure the application of a finely dispersed aerosol of an indicator formulation on the surface of the monodisperse jet.

Previously, fluorine and chlorine-containing freons were widely used for spraying liquids. Currently, due to their destructive effect on the ozone layer of the atmosphere, the use of freons is significantly limited.

Methods based on creating excessive pressure in an aerosol device due to nitrogen or atmospheric air have found wide application for spraying formulations.

However, the use of compressed nitrogen as a repellent requires special facilities for its production and refueling of aerosol devices.

The use of compressed air can be provided by the very design of the aerosol device. At the same time, air pressure is created by repeatedly pressing a special pear like spraying cologne in a hairdresser.

The disadvantage of this method is the need for a second channel for the output of the sprayed formulation.

Recently, aerosol devices have been used, in which compressed air pressure is created by repeatedly pressing the spray head of the pump.

In addition, conventional spraying devices, as a rule, do not allow to obtain a jet of fine monodisperse aerosol, which leads to erosion of the indication effect on the surface of objects.

Therefore, we have applied a spraying method based on the creation of pressure using a special design of the spray pump.

When the nozzle of the pump sprayer is repeatedly pressed in the bottle, excess air pressure is created and due to this, the indicator formulation is fed into the spray pump with its subsequent spraying onto the analyzed surface.

The design of the aerosol device and the spray pump used are shown in FIG. 12.

The aerosol device for the detection of aggressive acidic chemicals is a 150 ml spray can equipped with a spray bottle and filled with the appropriate indicator formulation.

The aerosol device (AC) shown in FIG. 1 consists of two components — the spray pump 1 and the bottle 2. In turn, the spray pump in accordance with FIG. 2 consists of the following parts: cap 3, buttons 4, pump-sprayer body 5, gaskets 6, piston 7, lock case 8, ball 9, base of lock 10, spring 11, valve body 12, tube 13. Bottle diameter and height of control unit selected taking into account the anthropometric characteristics of men in accordance with GOST 21114.

The applied AU also meets the requirements of GOST R 51760 for consumer plastic containers. The aerosol device is made of materials resistant to the indicator formulation.

The advantages of applying the method with an aerosol device over known methods, in particular over a piece of paper indicator or indicator tissue, are as follows:

longer shelf life of indicator formulation (more than 2 years); no need to use additional reagents for detection; no need for direct contact of the operator with the analyzed surface;

the multiple use of one package (at least 100 times), which allows you to repeatedly determine the pollution of the surface of the object; maintaining operability in the temperature range from minus 5 to plus 40 ° C; provides a large control area.

The proposed aerosol device (Fig. 1) for express detection of aggressive chemicals on the surfaces of objects is characterized in that due to the selection of material and the relative position of the parts relative to each other, the surface is irrigated with a monodisperse jet using an indicator formulation, which eliminates the erosion of the indication effect.

The conducted experimental storage showed the stability of the proposed indicator formulations during storage and maintaining the operability of the proposed method with aerosol devices for at least 2 years.

The technical result that can be achieved by using the present invention is the rapid detection of the presence on the large areas of the surfaces to be examined of traces of aggressive chemicals of an acidic nature.

Claims (1)

The use of an aerosol device for detecting substances by applying an aerosol of an indicator formulation to the test surface, followed by visual determination of an indication effect, characterized in that an aerosol device is used that provides spraying of an indicator formulation in the form of a monodisperse aerosol and containing a mixture of 0.05-0.1 wt.% solutions of two indicators of methyl red and methyl yellow in a ratio of 1: 1 by volume in ethanol, and to detect weak organic x acids used 0.05-0.1 wt.% solution of 4-dietilaminoazobenzola in ethyl alcohol.

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