RU2525427C2 - Method of preparing standard aerosol samples - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of preparing standard aerosol samples based on a mixture of fine powder containing defined elements is characterised by that a dispersed mixture of mineral, synthetic and biological materials is used, wherein grain size analysis is used to detect presence of said types of simulating materials and content thereof in a real atmospheric suspension in said region as applied to a specific season is determined.

EFFECT: providing maximum similarity of simulated atmospheric suspensions for different regions and conditions.

11 dwg

Description

The invention relates to analytical chemistry and experimental medicine, in particular to methods and means of manufacturing samples that simulate atmospheric aerosols in composition, and can be used to study their effect on the immunoallergic status of living organisms.

A known method of preparing standard samples of aerosols in the form of thin organic films, which is obtained by adding a standard solution containing determinable elements to a methyl cellulose solution, then the mixture is poured onto a cleaned glass plate located horizontally, dried in air at room temperature and samples of a predetermined shape are pressed from a polymer film size (see Billiet J., Pams R., Hoste J. Multielement thin film standards for XRF analysis // X-ray Spectrom. - 1980. - Vol.9, No. 4. - P.206-211).

The disadvantage of this method is the inadequacy of the obtained samples of the real samples of aerosols collected on the filter, physico-chemical properties due to the addition of the determined elements to the solution of methylcellulose in the form of soluble compounds. At the same time, atmospheric aerosols and industrial emissions into the atmosphere are mainly fine particles, including water-insoluble metal compounds (aluminosilicates, oxides, carbonates, etc.).

The closest in technical essence and the achieved result to the invention is a method for the preparation of standard aerosol samples based on a mixture of finely divided powder containing detectable elements (see RU No. 2239170, G01N 1/28, 2002). Then, the powder mixture containing the elements to be determined is mixed with dry powder of methyl cellulose and poured with distilled water heated to a temperature of 70-80 ° C, thoroughly mixed and kept at room temperature, stirring every 30 min for 2 hours. Next, the mixture is slowly poured onto a cleaned glass plate located horizontally. The dried polymer film is removed from the glass and samples of a given size are pressed from it.

The disadvantage of this solution is the rejection of approximately 5% of the specimens, while the instability in the chemical composition of the remaining individual specimens of standard samples is characterized by a coefficient of variation of 4-7% depending on the element being determined. The difference in the content of the elements being determined in individual copies of standard samples reduces the accuracy of monitoring the chemical composition of atmospheric aerosols loaded on the filter using various spectral and chemical analysis techniques. Another disadvantage of this method is the duration (about 3 hours) and the complexity (all operations are performed manually) of the process of obtaining a homogeneous mixture of the polymer solution and the determined components. At the same time, a significant drawback is the inability to use samples that simulate atmospheric aerosols in their composition when studying their effect on living organisms in an experiment, including immunoallergic status of living organisms.

The objective of the proposed method is to enable the use of samples that simulate the composition of atmospheric aerosols when studying their effect on living organisms in the experiment.

The technical result obtained by solving the problem is expressed in providing the possibility of using samples that simulate atmospheric aerosols in composition when studying their effect on living organisms in the experiment. At the same time, the possibility of maximum similarity of simulated atmospheric suspensions for different regions and conditions is provided.

To solve this problem, the method of preparing standard samples of aerosols based on a mixture of finely dispersed powder containing the elements to be determined is characterized in that they use a dispersed mixture of mineral, synthetic and biological materials, while the crushed zeolite tuff in two size fractions is used as a mineral component - up to 1 microns and from 1 to 100 microns, as a synthetic component, plastic is used, crushed to fractions of tens of microns, as a biological component isp a mixture of leaves and grass and / or animal hair and / or feathers of birds, representatives of the biosphere of the region, crushed to fractions of not more than 100 microns, is used; moreover, using the particle size analysis, the presence of the above types of modeling materials is determined and their content in the composition of the real atmospheric suspension in a given region in relation to a specific season.

A comparative analysis of the features of the claimed solution with the features of the prototype and analogues indicates the conformity of the claimed solution to the criterion of "novelty."

The features of the characterizing part of the claims provide a solution to a set of functional tasks.

The signs "... use a dispersed mixture of mineral, synthetic and biological materials" ensure the maximum compliance of real aerosol models with the composition of atmospheric pollution.

The signs "... crushed zeolite tuff is used as a mineral component" provide both good accessibility of this material as a raw material component and take into account the fact that zeolites are rocks of the weathering crust that are constantly in contact with living organisms due to their wide distribution (some of the most widely represented aluminosilicates, occupying the sixth place in the world in reserves).

Signs indicating that zeolites should be represented "... in two size fractions - up to 1 μm and from 1 to 100 μm", allow us to take into account the real particle size distribution of the mineral suspension, which is important in connection with the different mechanism of action of the said fractions on the human body (more large particles, taking into account the density of the material, do not pass further than the nasopharynx, and smaller particles do not settle in the upper respiratory tract due to their volatility): according to N.P. Yushkina (Bulletin of the Earth Sciences Division of the Russian Academy of Sciences - ELECTRONIC SCIENTIFIC INFORMATION JOURNAL L No. 1 (22) 2004, article “MINERAL WORLD AND HUMAN HEALTH”) each person passes about 12 m ^{3 of} air daily through his respiratory system, i.e. about 15 kg. In total, about 20 million tons of mineral matter are weighed in the Earth’s atmosphere. In industrial areas, their concentration is hundreds or even thousands of times higher; so that a person does not inhale clean air, but an air-mineral mixture, an aerosol with a particle size of 0.001 to 1000 microns. Each breath is drawing in up to a million mineral particles.

In the process of evolution of living organisms, a rather effective mechanism for cleaning inhaled air was developed: coarse particles (more than 5 μm) settle in the nasopharynx, up to 90% of small particles are retained in the upper respiratory tract and bronchi, from which they are removed along with mucus by expectoration. As our studies show, the penetrating ability of powdered materials in the respiratory tract depends not only on the particle size, but also on the breathing regime; with deep vigorous breaths (increased breathing intensity), the size of particles capable of penetrating the upper respiratory tract lies in the upper part of the claimed range (from 5-6 to 10 microns); under normal breathing conditions, the size of particles capable of penetrating the upper respiratory tract lies in the middle of the claimed range (from 2-3 to 5-6 microns); with a reduced intensity of respiration, the size of particles capable of penetrating the upper respiratory tract lies in the lower part of the claimed range (from 1-2 to 3-4 microns).

Signs indicating that “as a synthetic component use plastic, crushed to fractions of tens of microns”, take into account the really achievable particle size range of the synthetic component when grinding plastic (in the manufacture of the component during the implementation of the method), and recorded in real samples of aerosol.

Signs indicating that “as a biological component use a mixture of leaves and grass, and / or animal hair and / or feathers of birds, representatives of the biosphere of this region, crushed to fractions of not more than 100 microns”, provide the ability to accurately “bind” the properties of standard components aerosol samples to the real conditions of the region.

Signs indicating that “preliminary, using particle size analysis, reveal the presence of the named types of modeling materials and determine their content in the composition of real atmospheric suspended matter in this region”, provide the ability to accurately “link” the concentrations of components of standard aerosol samples and their material structure to similar parameters of real aerosols recorded in the conditions of this region.

Signs indicating that they detect the presence of the named types of modeling materials and determine their content in the composition of the real atmospheric suspension in the region “in relation to a specific season” allow us to take into account seasonal changes in the named parameters of real aerosols.

The claimed invention is illustrated by drawings, where Figs. 1-8 show samples of mineral suspension: Fig. 1 - from a sample of snow collected on the Skot peninsula (Magnification x16); figure 2 - from a sample of snow collected in the area of the First river (increase x10); figure 3 - from a sample of snow collected in the area of the street. Pushkinskaya (increase x8); figure 4 - from a sample of snow collected in the area of the Second River (increase x18); figure 5 - from a sample of snow collected in the region of Sadgorod (increase x8); figure 6 - from a sample of snow collected in the region of Emar (increase x8): figure 7 - from a sample of snow collected in the region of Zmeinka (increase x18); on Fig - from a sample of snow collected in the area of Tikhaya Bay (magnification x18); figure 9, a, b shows electron micrographs of a rubber particle from a sample collected in the area of the Second River (magnification a) x132 and b) x106); figure 10 shows electronic micrographs of particles of plastic (a) and glassy fiber from a sample collected in the area of Pushkinskaya Street (magnification a) x111 and b) x197); 11 shows electron micrographs of particles - fragments of marine organics from a sample collected near the sea, in samples of the Sadgorod (a) and Egersheld (b) regions.

The basis of the claimed invention are the following considerations.

Particles suspended in the atmosphere have a significant effect on air quality and climate. At the same time, the composition and pollution of atmospheric air are one of the leading risk factors for public health, for example, atmospheric pollution, reducing the body's immune resistance, is accompanied by an increase in infectious and allergic respiratory diseases.

Assessment of the atmospheric transport of matter and the total mass of suspensions made by different authors diverge tens and hundreds of times, which is associated with the imperfection of the applied methods and the limited capabilities of the applied measuring tools (see Glazovsky N.F. Geochemical flows in the biosphere. - M.: Partnership of scientific publications of KMK, 2006. 535 p.2).

In this regard, an assessment was made of the characteristics (material composition, size and content) of natural atmospheric suspensions using the example of the port city of Vladivostok. Samples (precipitation in the form of snow) were collected during the 2010-2011 winter season. during snowfalls. Sampling points were located in eight districts of Vladivostok: the Shkota peninsula (Krygina St. district); st. Pushkinskaya (funicular area); The first river (district of Komsomolskaya street); The second river (the intersection of Russkaya and Bagration streets); Sadgorod (seashore); Emar (seashore); Zmeinka (near Kosmodemyanskaya St.) and Tikhaya Bay (green zone at a distance of 500 m from TPP-2). To exclude secondary pollution with anthropogenic aerosols, only the top layer (5-10 cm) of freshly fallen snow was selected. Snow was placed in 1 liter sterile containers. After a couple of hours, when the snow in the containers completely melted, after shaking, 40 ml of liquid was collected from each sample and analyzed on a Analysette 22 NanoTech laser particle analyzer (Fritsch). This made it possible in one measurement to establish the distribution of particle sizes, and also to determine their shape. Suspension material analysis was performed using a Zeiss Discovery VI 2 light microscope (Germany) and a Zeiss Ultra Plus electron microscope with an energy dispersive spectrometer (Germany). Electron microscope samples were sprayed with gold.

In a typical sample taken on the Shkot peninsula (seashore) (Fig. 1), quartz, feldspar, quartz-feldspar splices, quartz with malachite films, kaolinite, hard-to-detect rock particles, siliceous-iron-oxide particles, glassy were revealed particles, technogenic particles of unknown origin, plagioclases, concrete particles, slag specs, plant detritus, rubber particles.

In the area of the First River (an industrial area with the presence of CHPP-1) (Fig. 2), soot, quartz, feldspar, bitumen, glass, rubber particles were detected. Soot in the form of a layer covers all other particles, but the prevailing in quantity are the natural mineral particles.

In the sample taken on Pushkinskaya street (industrial area) (Fig. 3), quartz, feldspar, synthetic fibers, soot (slag), iron oxides, films (organic and inorganic) were detected.

In the sample taken in the area of the Second River (an area with increased automobile load) (Fig. 4), quartz, rubber particles, feldspar, synthetic fibers, soot, slag, particles of unidentified organics were identified.

In the sample taken in the Sadgorod region (seashore) (Fig. 5), quartz, feldspar, slag, silt, plant detritus, unidentified organics (animal hair and fragments of plants or algae), synthetic particles, and coal particles were detected. Many particles are aggregated.

In the sample taken in the Emar area (seashore) (Fig.6), quartz, feldspar, plagioclases, epidotes, metal oxides, coal and asphalt particles, and plant detritus were detected.

In a sample taken in the Zmeinka region (seashore) (Fig. 7), quartz, feldspar, plagioclases, chalcedony, epidotes, and technogenic particles of unknown origin were identified.

In a sample taken in the vicinity of Tikhaya Bay (an industrial area near CHPP-2) (Fig. 8), soot, slag, quartz, feldspar, plagioclase, specs were detected.

For all districts of the city of Vladivostok, a pronounced regularity is observed between the ecological characteristics of the regions (for example, increased automobile load or proximity to the sea) and the composition of suspensions (rubber particles and organic fragments, respectively). So, in the area of the Second River with a high automobile press there were particles of rubber (Fig. 9, a, b); in the area of Pushkinskaya Street there are many technogenic particles, including plastic (figure 10, a) and glass (figure 10, b) fibers; near the sea, in samples of the Sadgorod district (Fig. 11, a) and Egersheld (Fig. 11, b), fragments of marine organics were found.

All observed particles of atmospheric suspensions can be divided into three groups: natural inorganic (particles of minerals), anthropogenic (particles of synthetics, slag, soot, etc.) and natural organic (pollen, fragments of insects and plants, animal hair, etc.), which correlates with observations of other researchers (see Ivanov V.V. The material composition of insoluble particles in the snow cover of Southern Sakhalin (data from electron microscopy and IR spectroscopy) / V.V. Ivanov, N.A. Kazakov, L.G. Kolesova and dr. // Abstracts of the International Symposium of the Physics, Chemistry, and Snow Mechanics Institute, Yuzhno-Sakhalinsk, 2011. P.33-37; VG Svinukhov, Research, Modeling and Forecast of Atmospheric Pollution in the City: Abstract of thesis, Doctor of Geography. Vladivostok, 1997. 44 pp .; Senotrusova SV Atmospheric pollution and the health status of the population of industrial cities. - St. Petersburg: Asterion Publishing House, 2004. 246 pp .; NK Khristoforova Environmental problems of the region: Far East - Primorye. - Khabarovsk book publishing house, 2005. 304 p .; Shevchenko V.P. Distribution and composition of insoluble particles in the snow of the Arctic / V.P. Shevchenko, A.P. Lisitsyn, R. Stein and others // Problems of the Arctic and Antarctic. 2007. No. 75. S.106-118).

It can be concluded that in a modern city (on the example of Vladivostok), despite a fairly large number of sources of technogenic atmospheric suspensions (TPP-1, TPP-2, 38 large boiler houses, an incinerator and about 350 thousand units of vehicles), the proportion of technogenic particles is not predominant and amounts to no more than 10-15%. This fact can be explained by the strong winter monsoon winds of the north-western points (from the mainland) characteristic of Vladivostok, the strong dissection of the territory, as well as the relatively thin snow cover.

Thus, the structure of standard aerosol samples was adopted as a mixture of mineral, synthetic and biological materials.

The claimed method is implemented as follows.

As a mineral component of the suspension, it is necessary to use crushed zeolite tuff in two size fractions:

- the first, the second - micro (1-100 microns) (its manufacture is provided by grinding sterilized (for example, by irradiation with ultraviolet) samples of crushed to 4-10 mm zeolite in an ultrasonic disintegrator, for example, Bandelin SONOPULS HD 2070 (operating frequency 22 kHz, maximum power 400 W)), subjected to grinding to obtain a fraction with a particle size of less than 100 microns;

- the second is nano (up to 1 μm) (its manufacture is provided by grinding in a varioplanetary mill, for example, pulverisette 4, a sample of micro-sized zeolite prepared in the first stage).

The synthetic component is crushed plastic (first crushed on a metal grater (to a granule size of less than 1 mm), and then in a planetary mill (up to tens of microns)). Further grinding due to the plastic properties of the material is not possible. The composition of the material for the manufacture of this component is determined by the composition of the real atmospheric suspension determined in the region for which the aerosol is simulated, using one, two, or three types of plastic identified in real aerosols of this region.

The biological component is a mixture of leaves of ground trees, algae, animal hair (cats, dogs), crushed in an ultrasonic disintegrator. The composition of the material for the manufacture of this component is determined by the composition of the real atmospheric suspension determined in the region for which the aerosol is simulated, using one or two types of materials whose share is not less than 15-20% in the composition of the sample of real aerosol in this region.

The monocomponents thus prepared are mixed in a known manner in a proportion corresponding to their proportions in the composition of the real atmospheric suspension determined in a given region or season using particle size analysis.

The material prepared in this way is used in a known manner, for example, a well-known (classical) scheme for studying the effect of a substance of real atmospheric suspensions on living organisms (laboratory animals) is experimentally used, using the claimed substance as adequate and repeatable experimental models of suspensions. In this case, the animals are inhaled in a known manner, for example, using a cage with dimensions exceeding that of the animal, equipped with a cover made of an airtight material, for example, polyethylene. In this case, an aerosol is introduced into the cavity of the cell, filling its internal volume, which causes the animal to inhale it. An ultrasonic nebulizer is used as a means of aerosol formation, for example, an ultrasonic portable inhaler UP-0.25 "ARSA" (into which a predetermined sample of sprayed material is loaded), the outlet channel of which is communicated with the cell cavity. The experimental animal is placed in a cage, after which an aerosol cloud is formed in the cell volume. The amount of sprayed material and the duration of the animal’s stay in the cage are taken based on the receipt of doses from 100 to 1000 mg / kg of weight to different groups of experimental animals (1 time per day up to 40 min). The group of control animals is not exposed to the drug.

After the experimental measures, on the day specified in the experiment, the animals are slaughtered simultaneously by decapitation and material is taken for research. Further, in a known manner, in accordance with the objectives of the experiment, laboratory animals are prepared, samples of the corresponding biological material are taken, and their analysis is carried out using appropriate laboratory means. For example, staining and preparation of smears for light microscopy for light-optical morphometry or photography or other manipulations are performed.

Claims (1)

A method of preparing standard aerosol samples based on a mixture of finely divided powder containing detectable elements, characterized in that a dispersed mixture of mineral, biological and synthetic materials is obtained by mixing them in proportions corresponding to their fractions in a real atmospheric mixture, while as a mineral the material is used crushed zeolite tuff in two size fractions - up to 1 micron and from 1 to 100 microns, as biological material is used crushed to fractions not more than 100 microns a mixture of leaves and grass, and / or animal hair, and / or feathers of birds, representatives of the biosphere of this region, and plastic is used as a synthetic material, crushed to fractions of tens of microns, then an aerosol is formed using an ultrasonic inhaler, and previously using granulometric analysis, the presence of the named mineral, biological and synthetic materials is detected and their content in the composition of real atmospheric suspension is determined, in this region with respect to indiscrete season.

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