RU2436082C2 - Method and composition of indicator formulation for rapid detection of disinfectants with oxidative active substance on surfaces of objects and determining completeness of disinfecton - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method and composition for indicator formulation for detecting oxidative substances acts on horizontal, inclined and vertical surfaces and is deposited by spraying the analysed surface using an aerosol device. The indicator formulation used is a composition consisting of the following components (in wt %): potassium iodide 0.1-0.2; starch 0.1-0.2; acetic acid 1.0-1.5; sodium acetate trihydrate 2.0-3.0; glycerin 5.0-10.0; distilled water - up to 100. Completeness of disinfection after not less than 0.5 hours and not later than 2 hours after treatment is carried out based on the indication effect - blue colour of the object.

EFFECT: invention ensures stability of the indicator formulation during storage.

6 cl, 2 dwg

Description

FIELD OF THE INVENTION

The invention relates to the field of research or analysis of substances of an oxidizing nature by chemical methods, specifically using chemical indicators, and is intended for rapid detection of the active substance of disinfectants on the surfaces of objects.

State of the art

In the complex of anti-epidemic and sanitary-hygienic measures carried out in infectious foci, an important element is the disinfection of surfaces. Existing methods for assessing the completeness of disinfection of various surfaces using microbiological and molecular genetic methods of analysis are long-term, their implementation requires high professional training of specialists, the presence of special laboratory conditions, preliminary preparation of samples aimed at neutralizing the active substance, etc. In addition, the time for receiving an answer about the presence (or absence) of infectious disease pathogens in samples can reach several days.

According to existing requirements, disinfection of surfaces is carried out taking into account the established norms of their consumption per unit area, depending on the type of infection: spore-forming or non-spore-forming forms of microorganisms. Failure to comply with the requirements for disinfectant consumption rates leads to the residual contamination of objects, which, along with untreated surfaces, can serve as a source of infection.

Therefore, it is proposed to judge the completeness of disinfection by the presence of a residual amount of disinfectants on the surfaces of objects.

In this regard, the development of means of rapid control of the presence of disinfectants on the surfaces of objects is an urgent task.

Known methods for determining the quality of disinfectant formulations of an oxidizing nature in solutions using indicator papers (G01N 31/22, G01N 21/78, Patent No. 23182 "Indicator for the semi-quantitative determination of active chlorine in disinfecting solutions of bleach and sodium and calcium hypochlorites."

Indicator papers and indicator napkins of the “Desicont-chlorine” type can also be used for the qualitative determination of traces of chlorine-containing disinfectants on the surfaces of medical, food equipment and walls of rooms after disinfection. However, the modes of their use for this purpose have not yet been worked out; before the detection, they must be wetted with water, which makes it necessary to supplement them with an additional dropper. The performance of indicator wipes is maintained only at temperatures above plus 5 ° C. The shelf life in a sale package is 12 months, and in an opened package they must be used for no more than 3 days.

Napkins "Desicont-chlorine" are strips of base paper with a size of 50 × 50 mm, impregnated with an indicator composition and packaged in 1, 3, 5 or 10 pcs. in bags of metallized film. The sensitivity of the indicator wipe is 5 mg / l ^-1 for active chlorine. The determination of traces of disinfectants is carried out visually by the appearance of a pale pink to brown color indicator wipe after contact with the test surface. For detection, the napkin must first be moistened with water, and then wipe its examined surface.

Napkins are made by NPF VINAR in accordance with TU 2642-031-11764404-2003. Warranty period for storing napkins is 12 months. Storage conditions: at temperatures from plus 5 to plus 40 ° C, relative humidity 80%, excluding direct sunlight, exposure to vapors of chemicals, water, precipitation. Transportation at a temperature of minus 15 ° C is allowed.

Disclosure of invention

We propose a method and composition of an indicator formulation for express detection of oxidizing substances on the surfaces of objects using an aerosol device.

A prototype aerosol device for detecting substances of an oxidizing nature has been developed.

The aerosol device for detecting oxidizing agents is a 150 ml spray can, equipped with a nebulizer and filled with an indicator formulation for substances of an oxidizing nature (substances containing active chlorine, hydrogen peroxide, and others). The device’s action is based on a redox reaction that occurs during the interaction of oxidizing agents with a solution of potassium iodide and starch and leads to the appearance of a characteristic blue color of the complex of iodine formed with starch.

The aerosol device (AU), shown in Fig. 1, consists of two components - a spray pump 1 and a bottle 2. In turn, the spray pump in accordance with Fig. 2 consists of the following parts: cap 3, buttons 4, housing spray pump 5, gasket 6, piston 7, lock case 8, ball 9, lock base 10, spring 11, valve body 12, tube 13. The diameter of the bottle and the height of the AU are selected taking into account anthropometric signs of men in accordance with GOST 21114. The developed AU also meets the requirements of GOST R 51760 for t Areas of consumer polymer. The aerosol device is made of materials resistant to the indicator formulation.

The advantages of using an aerosol device over known methods, in particular over an indicator napkin, 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 indicator formulation used is not flammable and toxic;

Freon with its ozone-depleting potential is not used;

the aerosol device is made of polymeric materials and is corrosion-resistant and shockproof;

sampling with their subsequent processing and analysis in a specialized laboratory is not required;

convenience and safety in use;

preservation of analytical properties in the presence of possible impurities (oil, fuel, etc.);

allows for rapid detection on vertical, inclined and horizontal surfaces;

the formulation is prepared on the basis of aqueous solutions and is non-toxic and non-combustible, in case of contact with exposed skin it is enough to wash it off with soap and water;

provides a contrasting and time-stable indication effect, lasting at least 30 minutes.

The proposed aerosol device (Fig. 1) for express detection of substances of an oxidizing nature by the above method is characterized in that due to the selection of material and the relative position of the parts relative to each other, it provides surface irrigation with an indicator formulation.

Analytical and experimental studies have shown that the composition of 55 ... 65 wt.% Low density polyethylene (LDPE) and 35 ... 45 wt.% High density polyethylene (HDPE) with the exception of the ball is the best option for the manufacture of the body and parts of the spray pump of the aerosol device 9 and springs 11 in accordance with the figure (figure 2) made of stainless steel.

This range is due to the following factors:

the use of HDPE for the manufacture of products is complicated due to its high degree of crystallinity;

the use of LDPE is not recommended, since the products will not be rigid enough;

the use of mixtures with a small amount of HDPE (up to 10 wt.%) for the manufacture of the body is also not recommended, since such a mixture composition has a higher permeability according to the recipe.

Conducted experimental storage showed the stability of the indicator formulation when stored in an aerosol device and the preservation of its performance for at least 2 years.

The implementation of the invention

Experimental studies have shown that indicator formulation has the highest sensitivity, speed and specificity, which has the following composition (wt.%):

potassium iodide 0.1-0.2 starch 0.1-0.2 acetic acid 1.0-1.5 sodium acetate three-water 2.0-3.0 glycerol 5.0-10.0 distilled water up to 100

With a lower content of potassium iodide and starch, the obtained indication effect is not clear, and the use of higher concentrations of starch and iodine is impractical due to their limited solubility in aqueous solutions. Acetic acid and sodium acetate were used to obtain a buffer mixture with an optimal pH value at which the indicator formulation retains its working capacity for a long time, and the indicator reaction proceeds at a high speed.

Glycerin was added to the formulation in order to lower the lower range of operating temperatures.

To detect a disinfectant formulation directly on the surface of objects that have been treated with an oxidizing disinfectant, using the aerosol device, the following operations are carried out:

remove the cap from the spray pump, bring the aerosol device at a distance of 10-20 cm from the surface being monitored, taking into account the direction of the wind;

repeatedly pressing the button of the pump-sprayer, spray the indicator solution on the examined surface;

observe the appearance of an indication effect on a controlled surface.

The appearance of color in accordance with the standard indicates the presence on the surface of disinfectant formulations of an oxidizing nature.

Indication effect persists for at least half an hour.

In cases where the indication effect is not obvious, and also when the surface color coincides with the color of the indication effect, a cotton-gauze disk or a strip of filter paper is wetted with the indicator formulation, they wiped the analyzed surface with an area of about 100 cm ² and the appearance of the indication effect on the surface of the filter paper was observed . It is possible to apply the indicator formulation directly to the test surface, followed by rubbing it with a cotton-gauze disk.

Under the conditions of the experiment, they were applied to stainless steel, aluminum, and tile plates and painted with XB-518 paint with an area of 100 cm each by irrigation using a 1% aqueous solution two-thirds of the basic salt of calcium hypochlorite (DTS-GK) with a flow rate of 1.0 l / m ² .

The application of a 1% solution of DTS-HA on the surface was carried out by spraying it using an aerosol device. The dispersion of the aerosol disinfectant formulation was 100-200 microns. After applying the disinfectant formulation, the surfaces and detection tools were kept at the test temperature (minus 5, plus 20 and plus 40 ° C) for at least 0.5 hours. After 0.5 hours, 1 hour and 2 hours after applying the disinfectant formulation to the plates wet cotton-gauze discs or strips of filter paper from an aerosol device with indicator formulation. Then, sampling of the disinfecting formulation was carried out by rubbing them with the entire treated surface without violating its integrity for 1 min.

On other plates with a disinfecting formulation from a distance of 10-20 cm, as well as on cotton-gauze discs and strips of filter paper, an indicator formulation was applied from an aerosol device to detect disinfecting formulations of an oxidizing nature.

The appearance of a characteristic indicator effect on cotton gauze disks and filter strips was observed.

In the case of spraying the indicator formulation from the aerosol device directly onto the analyzed surface, the appearance of an indication effect on this surface was observed. The time of occurrence of the indicator effect was recorded. The test results are shown in the table.

The results of the tests showed that the aerosol device without the use of additional devices and reagents maintains its operability and ensures the detection of disinfecting formulations of an oxidizing nature (monochloramine, dichloramine, sodium salt of dichloroisocyanuric acid, calcium hypochlorite, sodium hypochlorite, bleach, hydrogen peroxide, peracetic acid, nitric acid acid, etc.) on various surfaces in the temperature range from minus 5 to plus 40 ° C 2 hours after surface treatment disinfectant formulation.

Thus, the proposed method and composition of the indicator formulation provide rapid detection of oxidizing substances on the surfaces of objects in a wide range of operating temperatures. The aerosol device has a low cost, optimal weight and size characteristics, provides a low specific consumption of indicator formulation, when spraying, the required dispersion and uniformity of the spray torch are achieved.

As oxidizing substances, monochloramine, dichloramine, sodium dichloroisocyanuric acid, calcium hypochlorite, sodium hypochlorite, bleach, hydrogen peroxide, nitric and peracetic acids can be found.

Each aerosol device is labeled by offset printing on self-adhesive white semi-gloss paper that is resistant to aggressive media.

The label contains:

Conditional and full name of the product;

volume of indicator formulation;

information about the purpose of the AU and the method of its use;

indication effect when oxidizing substances are detected;

production date;

shelf life.

Aerosol devices can be supplied as a kit. Such a kit is intended for express detection of oxidizing substances on horizontal, inclined, and vertical surfaces. The kit is shown below.

Aerosol device for express detection of substances 2 oxidizing nature, pcs., including: spray pump one case, pcs. one indicator formulation, l 0.12 label, pcs. one Set of accessories, pcs., Including: one spray pump one cotton-gauze disk ⌀ 60 mm, pcs. one hundred operational documentation, set one cardboard packaging, pcs. one

The main characteristics of the kit for express detection of oxidizing substances are determined:

preparation time for work, no more, min one detection time of oxidizing substances, no more than min four time of preservation of indication effect, not less than, min thirty threshold sensitivity, mg / ml 5 · 10 ^-2 operating temperature range, ° С minus 5-plus 40 AU mass, kg, no more 0.15 size of detected drops, not less than, microns 150 frequency of use, not less 150 warranty period of storage, not less than, years 2

Scopes of a set:

checking the quality of disinfection by the presence of a residual amount of the active substance of the disinfectant after irrigation of the surface;

identification of leaks (spills), contamination and cleanliness of the surfaces of objects after transportation of nitric acid and other oxidizing agents.

The proposed technical solution is industrially applicable, since standard equipment and widespread materials and chemical reagents can be used for its implementation.

Claims (6)

1. The method of rapid detection of disinfectants with an active substance of an oxidizing nature on the surfaces of objects, characterized in that the detection is carried out by spraying indicator formulations, including, wt.%:
potassium iodide 0.1-0.2 starch 0.1-0.2 acetic acid 1.0-1.5 sodium acetate three-water 2.0-3.0 glycerol 5-10 distilled water up to 100
using an aerosol device with subsequent registration of the resulting indication effect - blue staining of the object. 2. The method according to claim 1, characterized in that the aerosol device consists of a bottle and a spray pump, the pressure necessary to spray the indicator formulation is created without using freon mechanically by repeatedly pressing the button of the spray pump, the design of the spray pump due to selection the material and the relative positions of the parts relative to each other provides surface irrigation with an indicator formulation, while the bottle and parts of the spray pump of the aerosol device are made of material fishing resistant to indicator recipe. 3. The method according to claim 1, characterized in that the bottle and parts of the spray pump (except for the ball and spring made of stainless steel) are made of a composition consisting of 55 ... 65 wt.% Low density polyethylene and 35 ... 45 wt. % high density polyethylene. 4. The method according to claim 1, characterized in that if the indication effect is masked by the color of the surface, then the indicator formulation is applied by spraying from an aerosol device onto a cotton pad (or a strip of filter paper), wiping the surface to be examined and observing it on the disc ( bar) indication effect. 5. A method for detecting the completeness of disinfection of surfaces of objects, characterized in that the quality of disinfection is judged by establishing the presence of a residual disinfectant determined by the method of rapid detection of the active substance of an oxidizing nature on the surfaces of objects according to claim 1, after at least 0.5 hours after the disinfection processing. 6. The composition of the indicator formulation for use in the method of rapid detection of disinfectants according to claim 1, characterized in that the composition contains, wt.%:
potassium iodide 0.1-0.2 starch 0.1-0.2 acetic acid 1.0-1.5 sodium acetate three-water 2.0-3.0 glycerol 5-10 distilled water up to 100

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