SU1762935A1 - Method of gaseous sterilization - Google Patents

Abstract

Use: instrument making, medicine, protection of objects from biodeterioration. SUMMARY OF THE INVENTION: Objects to be processed are placed in a chamber. The chamber is heated to 50 - 70 ° C and evacuated to 0.3-0.5 atmospheres. As a sterilizing agent, citral-based essential oil with a concentration in the vapor of 10–50 g / m3 is used. The treatment is carried out for 60 minutes. The chamber after processing the objects is filled with sterilized air and opened.

Description

The invention relates to the protection of products from bio-damage and can be used in instrument-making, light, food and textile industry, medicine and other areas of science and technology.

Known chamber, physical, gas and chemical methods of sterilizing products (see Ilyichev VD, Bocharov B.V., Gorlenko, MV Ecological basis for protection against biodegradation. Ed. Science, M., 1985 - 264s,).

There is a method of gas sterilization, which consists in creating full moisture saturation inside the chamber, then bromomethyl is fed through the heated tube, exposure is given, filtered air is directed into the chamber (see auth.ccssSR Mg 238103 from 20.11.69g. , MKI A 61 L2 / 20).

However, this method is used to sterilize a certain range of materials that are resistant to bromomethyl and moisture. However, it cannot be used to sterilize products from polymers, optoelectronic equipment and devices, fabrics, leather and wood because of the negative effect of moisture, bromomethyl and insufficient efficiency.

The purpose of the invention is to eliminate corrosion of materials, increase safety, resistance to re-contamination.

The goal is achieved by placing the products to be sterilized in a heated chamber, covering it and exposing it. After exposure, a vacuum is created in the chamber, essential oils containing monoterpenes are introduced into it through a nozzle, exposure is performed, after which filtered air is directed into it and opened.

Essential oils containing monoterpenes, such as citral, citronellal, geraniol, myrcene, avgenol, carvacrol, etc., actively suppress the viability of microorganisms (see Ayseman B.Ye., Smirnov V.V., Bondarenko A.S. Phytoncides and antibiotics of higher plants. Izd.Naukova Dumka, Kiev, 1984 - 280s.).

The high antimicrobial activity of monoterpene-containing essential oils is associated with their simultaneous and joint effect on the microbial cell. In some cases, monoterpenes block the sulfhydryl groups of enzymes (see Belo h |

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Mustache MA, Rostov I.Ya. About pseudo-allits. The Journal of General Chemistry, 1950, 20, p. 1701), in others - violates the functions of glucose dehydrase, glutamic acid aminferase, and phosphorus metabolism (see Sarek A., Fitoncidy koreni, 1. Cdeleni. - Prum. Potravin. 1955,6, No. 9, p.433.,. 435), thirdly uncouple the process of respiration, protein synthesis, inhibit the process of sporulation (see Aisemann, BE, et al. Phytoncides and antibiotics of higher plants. Ed. Naukova Dumka, Kiev, 1984, p.171 ... 193).

In terms of their physical properties, monoterpene-containing essential oils are oily liquids, insoluble in water, with a boiling point of more than 200 ° C, relative density at 20 ° C less than a unit. Evaporating from the filter paper substrate, it does not leave a stain. But the process of evaporation of oils is long and in the open air is more than 1.5 months in time. And, as studies have shown, the effectiveness of the inhibition of the viability of microbes and their adsorption on materials depend on this.

To accelerate the process of evaporation of the essential oils in the chamber, to increase the adsorption of their molecules on the materials of the products being sterilized, temperature and vacuum factors were used.

Thus, in the process of exposing products in a closed chamber at elevated temperatures, partial evaporation of moisture from the macropores occurs, redistributing it between them and the continuity of the wet film in some sections of materials disrupts due to a decrease in the surface tension of the solid-air-water interface. and air out of macropores. All this helps to increase the adsorption of molecules of essential oils on materials. Some cells die under the influence of heat on them.

The degree of dilution in the chamber is determined according to the laws of phase equilibrium (see Kireev, VA, Physical Chemistry Course, M., Khimi, 1975, P.323 ... 344), based on the relative volatility of essential oils and the heating temperature. When the evaporation of essential oils in the chamber at elevated temperature and vacuum occurs, several processes simultaneously occur. First, the partial pressure of the vapor of the essential oils in the chamber increases, because of which the effect of their action on the microbial cells increases and they die quickly. Secondly, this increases the adsorption of the molecules of essential oils on the materials of the sterilized products in the direction of the gradient.

concentration. Thirdly, increased temperature and rarefaction increase the permeability of the outer membrane of cells for the molecules of essential oils. Last easy

penetrate the cell and infect it. Thus, the sterilization of materials and products is achieved both by increasing the temperature and by diluting the microbial cells.

essential oils.

Example. They carried out the sterilization of electronic devices boards with elements mounted on them (microchips, resistors,

capacitors, connectors, etc.), samples of tarpaulin and polystyrene. For this, three samples of boards measuring 75x47 mm with elements hinged on them were taken, a tarp of linen fibers 75x50 mm in size, polystyrene 60x40 mm in size, examined them visually and with the help of optical means not subject to the absence of contamination and bioproving (mold) . For sterilization, an essential oil based on citral composition was taken,% by weight; citral 96%, monoterpene alcohols 1-2%, monoterpene carbohydrates 2 - 3%. The relative density of the oil is d 420 0.888 - 0.895. According to the nomogram (see the Course of Physical Chemistry, Kireyev VA, p. 343), based on the relative density of the essential oil and the heating temperature of the chamber, which is selected in the range of its influence on the change in the properties of the products to be sterilized and in this case is 60 ° C, the dilution pressure was determined. It is equal to 380 mm Hg. or 0.5 atm. This pressure corresponds to the saturation pressure of the chamber with vapors of the essential oil. They warmed the chamber to

60 ° C, the samples were placed in it, closed, and given an exposure time of 15 minutes. This time, as practice has shown, is enough to warm up the samples. Then the chamber was sealed, a vacuum of 0.5 was created in it.

atm and the essential oil was injected into it at the rate of 15 g / m3. After the essential oil was introduced into the chamber, an exposure time of 60 minutes was given, then filtered air was let in and opened. Sterilized samples were hung out one by one on the stand of the climate station and watched them during the entire warm season.

The second batch of samples (one image of each type) was wrapped in wrapping paper, placed in a thermostat and thermostatically controlled for a year at a temperature of 29 ± 2 ° C.

A third batch of samples was placed in plastic bags thermostatically

at a temperature of 32 ± 2 ° С for 12 months in desiccators, at the bottom of which distilled water was poured. In parallel, a blank experiment was set up in which, after heating the chamber, placing materials and products into it, exposing, creating a vacuum, the essential oil was not injected. Examination of the samples was carried out every ten days.

The test results are shown in the table. The data obtained indicate that effective concentrations of essential oils are concentrations from 10 to 50 g / m3, and the exposure time after introducing them into the chamber is at least 60 minutes. In the case where the exposure time after the introduction of the essential oil in the chamber exceeds 60 minutes, no increase in the sterilizing effect is observed. Pr concentration of essential oil more than 50 g / m materials and products become sticky due to an excess of essential oil. Dust quickly settles on them with all the consequences following from here.

The use of the present invention has the following advantages:

the selection of the temperature of the heating chamber and the vacuum is carried out by a simple nomogram, which allows you to pre-select such values that will not adversely affect the products to be sterilized;

citral-based essential oil is inert to materials and safe for humans at any concentrations, and having high antimicrobial activity and good ability to adsorb on materials, it ensures sterility of the product for a long time;

there is no need to process products before using them for their intended purpose;

essential oils of domestic production are cheap, which allows the invention to be put into practice as soon as possible.

Claims (1)

Claims The method of gas sterilization, including placing processed objects in a sealed chamber, heating and vacuuming the chamber, introducing a sterilizing agent into the chamber, exposing, filling the chamber with filtered air, and opening the chamber, which in order to avoid corrosion of materials, increase safety , resistance to re-contamination, the essential oil based on citral is used to heat the chamber up to 50-70 ° C as a sterilizing agent, evacuate to pressure 0.3 - 0.5 atm after 15-minute exposure of the heated chamber, produce a concentration of sterilant vapor in the 10 - SG g / m, and the processing of objects is carried out for 60 minutes. Biodegradability of ester-protected samples of materials and products points {GOST 9.01 (8-89)