RU2697479C1 - Method of determining concentration of rare-earth elements: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, in air of the working zone by mass spectrometry with inductively coupled plasma - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to analytical chemistry and can be used in production air quality control of working area. Method of determining concentration of rare-earth elements: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, in the air of the working zone by mass spectrometry with inductively coupled plasma involves sampling air of the working zone by drawing the analysed air in volume of 0.1–1.5 m³ through an analytical aerosol filter for 5–15 minutes, fixation of air temperature and atmospheric pressure at the moment of sampling, after sampling air filter is decomposed in the tube-type heater, for this filter is placed in a test tube for the tube heater, adding 4.0 cm³ to it concentrated nitric acid, the mixture is held for 2.5–3.0 hours at temperature of +95 °C, cooled to room temperature, deionised water volume is reduced to 10 cm³, the content is mixed, then 0.5 cm³ prepared samples are introduced into a test tube of an automatic sampler of a mass spectrometer, diluted with 4.45 cm³ deionised water is added to produced mixture 0.05 cm³ solution of internal indium standard in deionised water with mass concentration of 1,000 mcg/dm³ and in obtained sample by mass spectrometry with inductively coupled plasma, concentration of rare-earth elements is determined: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, using a calibration curve and taking into account the reduction of the volume of air sampled for analysis to normal conditions, wherein the helium feed rate in the mass spectrometer is 4.5 ml/min, and the rate of delivery through the mass spectrometer of the prepared sample is 0.4 ml/min.

EFFECT: providing high sensitivity, accuracy and rapidness of determining rare-earth elements (REE) in the air of a working area.

1 cl, 9 tbl

Description

The invention relates to the field of analytical chemistry and can be used by laboratories of institutions of the state sanitary and epidemiological service, research institutes working in the field of environmental hygiene in the implementation of industrial control over the air quality of the working area and the prevention of adverse effects on the health of working harmful chemicals. The invention is intended for measuring in the air of the working zone mass concentrations of 15 rare-earth elements (hereinafter - REE): lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, yttrium.

The industrial application of the elements of this group is constantly expanding, which is typical for the new era of nanotechnology. REEs are used in the optical industry, laser technology, rocket and space technology, nuclear energy, catalysis, the production of conventional and superconducting ceramics, the manufacture of superconducting films, paints, pigments, in medical examinations.

To improve occupational safety, maintain good hygiene, and study the effects of the ultra-small effects of REE, it is necessary to obtain accurate data when studying occupational risk. For these purposes, modern highly sensitive methods of elemental analysis are needed.

Currently, in the Russian Federation there are no officially approved methods for determining REE in the air of the working zone by inductively coupled plasma mass spectrometry. In this regard, it is necessary to develop a methodology for determining the quantitative content of REE in air precisely by the ICP-MS method. This problem is relevant.

The prior art methods for determining REE in the air of the working area using the following methods and standards: photometry (guidelines (MU) No. 2250-80, No. 5913-91), flame photometry (MU No. 2011-79), spectrography (MU No. 2240-80), for measuring nine REE the ISP-AE method (Measurement Method No. 41-515), for measuring one REE of yttrium - the method of atomic emission spectrometry with inductively coupled plasma (hereinafter - ISP-AE) (GOST R ISO 15202 Standard -2-2014), and inductively coupled plasma mass spectrometry method (hereinafter - ICP-MS) (Standard ISO 30011: 2010 or G ST R ISO 30011- 2017).

The parameters of these known methods and standards in relation to the defined REE and the ranges of their determined concentrations are presented in table 1.

The disadvantages of these known methods are:

- in methods 1 and 2, the impossibility of simultaneously determining several chemical elements, the time-consuming process of sample preparation, the need for accurate observance of the time from the moment of preparation of the samples to the moment of measurement on the device,

- method 3 does not indicate the possibility of determining yttrium and cerium, the error in determining REE (± 40%), which does not meet the requirements for methods for determining the concentrations of pollutants in the air of the working zone, which should not exceed 25% (GOST 12.1.016),

- in method 4, in accordance with MI No. 41-515, 10 REEs are determined from the required 15, and for praseodymium, europium and neodymium, the requirements for the upper measurement range, which should be at least twice the control standard, do not meet (GOST R EH 482 -2012), in addition, in method 4 described in GOST R ISO 15202-2-2014, only yttrium can be determined from REE.

Method 5 described in the international standard ISO 30011: 2010 “Air of the working area. Determination of the content of metals and metalloids in particles suspended in the air using inductively coupled plasma mass spectrometry "indicates only the possibility of determining one REE - yttrium, but the standard does not indicate either the determination ranges or specific sample preparation operations for it , also the values of metrological characteristics are not indicated.

From the database of patent materials, only methods for determining various metals in air are known (RF Patents No. 2466096, 2627854) and they are not applicable for determining REE in the air of a working area.

Moreover, the known methods for determining the concentration of rare-earth metals: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, in the air of the working zone by the method have not been identified mass spectrometry with inductively coupled plasma, therefore, it is not possible to make the choice of the closest analogue to the claimed object.

The technical problem solved by the proposed method is to provide the possibility of determining from one sample 15 rare earth elements in the air of the working area in a wide range of concentrations, ranging from 0.000007 mg / m ³ (the determination of low concentrations is necessary when studying the effects of ultra-small effects of chemical elements on health workers).

The technical result of the proposed method is to provide high sensitivity, accuracy and expressness of the determination of REE in the air of the working area.

The technical result achieved is achieved by the proposed Method for determining the concentration of rare-earth elements: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, in the air of the working zone by mass spectrometry with inductively coupled plasma, characterized in that a sampling of the air of the working area is carried out by pulling the test air with a volume of 0.1-1.5 m ³ through an analytical aerosol filter for 5-15 minutes, fix the temperature air urine and atmospheric pressure at the time of sampling, after sampling the air, the filter is decomposed in a test tube heater, for this the filter is placed in a test tube for a test tube heater, 4.0 cm ^{3 of} concentrated nitric acid is added to it, the mixture is kept for 2.5 -3.0 hours at a temperature of + 95 ° C, cooled to room temperature, bring the sample volume to 10 cm ³ with deionized water, mix the contents, then add 0.5 cm ^{3 of the} prepared sample to a test tube of an automatic sampler of a mass spectrometer, dilute it with 4.45 cm ^{3 of} deionized water, add 0.05 cm ^{3 of a} solution of the indium internal standard in deionized water with a mass concentration of 1000 μg / dm ³ to the resulting mixture, and the concentration of rare earths is determined in the resulting sample by inductively coupled plasma mass spectrometry elements: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, using a calibration graph and taking into account the reduction in the volume of air selected for analysis, to normal conditions, while the feed rate of helium in the mass spectrometer is 4.5 ml / min, and the feed rate through the mass spectrometer of the prepared sample is 0.4 ml / min.

AFA filters are used as an analytical aerosol filter.

The specified technical result is achieved due to the following.

The proposed method differs from the currently existing methods by the measurement method based on the use of inductively coupled argon plasma as a source of ions and a mass spectrometer for their separation and detection, on the use of helium to cancel interference, by the conditions of sample preparation, by expanding the list of rare earths determined from one sample elements.

Thus, the claimed technical result is achieved through the use of a highly sensitive and selective ICP-MS method in the mode of a reaction cell with helium, a combination of certain operations, their sequence and modes in the claimed method, as well as due to the combination of reagents used in sample preparation (establishment of analysis conditions on a mass spectrometer, methods and conditions for sample preparation, selection of conditions for the preparation of chemical glassware, the use of high-purity reagents and materials).

The proposed method was tested in laboratory conditions. The following substances and equipment were used for its implementation:

- A multi-element calibration standard with a concentration of 10 mg / l of cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, scandium, samarium, terbium, thorium, thulium, yttrium, ytterbium in 5% nitric acid. Relative error of certified values with a confidence level of 0.95: δ = ± 0.5% (Multi-element Calibration Standard 1, USA);

- Highly pure nitric acid, GOST 11125;

- Deionized water, GOST R 52501;

- A solution for adjusting the sensitivity of a mass spectrometer containing lithium, magnesium, yttrium, cerium, thallium, cobalt 1 μg / dm ³ or 10 μg / dm ³ ;

- A solution containing the element of comparison of indium 10 mg / DM ³ ;

- Argon liquid high purity (99.998%), TU-2114-005-00204760-99;

- Gaseous helium of high purity (99.995%), TU0271-135-31323949;

- Inductively coupled plasma mass spectrometer Agilent 7500 _cx with the following characteristics:

mass scanning range, amu: 2-260;

detection limits: beryllium ≤1.5 ng / dm ³ , indium ≤ 0.5 ng / dm ³ , bismuth ≤0.5 ng / dm ³ ;

sensitivity (imp./s per 1 mg / dm ³ ): lithium (7) ≥30⋅10 ⁶ ,

strontium (88) ≥80⋅10 ⁶ , thallium (205) ≥40⋅10 ⁶ ;

short-term stability, standard deviation: ≤ 3%;

long-term stability, standard deviation: ≤ 4%;

doubly charged ions, (cerium ²⁺ / cerium ⁺ ): ≤ 3%;

oxide ions, (cerium oxide II / cerium): ≤ 1.5%;

background level on mass 9 (Be): <5 pulse / s;

detector speed: ≥ 100 μs per 1 ion;

MicroMist microaerosol spray;

peristaltic pump for sample supply;

spray chamber with electronic Peltier cooling;

injector diameter 2.5 mm.

- Aspirator for air sampling (TU 4215-000-11696625);

- Test tube HotBlock ™ heater;

When carrying out the processes of preparing solutions and preparing samples for analysis, the following conditions are met:

- air temperature (20 ± 5) ° С;

- atmospheric pressure 630-800 mm RT. st .;

- humidity from 30 to 80%.

Preparation of stock solutions

1. Preparation of stock solutions using a multi-element solution as the initial solution (for example, Multi-Element Calibration Standard-1 manufactured by Agilent Technologies, USA) with mass concentrations of the analyzed elements (Ce, Dy, Er, Eu, Gd, Ho, La, Lu , Nd, Pr, Sc, Sm, Tb, Th, Tm, Y, Yb) 10 mg / dm ³ .

1.1 Solution No. 1 with mass concentrations of ions of the analyzed elements 100 μg / DM ³

Solution No. 1 is prepared from the initial solution with mass concentrations of the analyzed elements of 10 mg / DM ³ .

In a volumetric flask with a capacity of 50 cm ^3, add an automatic dispenser or pipette of 0.5 cm ^{3 of the} initial solution and bring the volume of the solution in the flask to the mark with a 1% nitric acid solution.

1.2 Solution No. 2 with mass concentrations of the analyzed elements of 50 μg / DM ³

Solution No. 2 is prepared from a solution of the initial sample with mass concentrations of the analyzed elements of 10 mg / DM ³ .

In a volumetric flask with a capacity of 100 cm ^{3, a} 0.5 cm ³ solution of the initial sample is dispensed or pipetted and the volume of the solution in the flask is adjusted to the mark with a 1% nitric acid solution.

1.3 Solution No. 3 with mass concentrations of the analyzed elements of 10 μg / DM ³ .

Solution No. 3 is prepared from solution No. 1 with mass concentrations of the analyzed elements of 100 μg / DM ³ .

In a volumetric flask with a capacity of 50 cm ³ make a dispenser or pipette 5 cm ^{3 of} solution No. 1 and adjust the volume of the solution in the flask to the mark with a 1% nitric acid solution.

2 Preparation of internal standard solution

The solution of the internal standard with a mass concentration of the element of comparison of indium 1000 μg / DM ³ .

Prepared from a basic solution with a mass concentration of the indium comparison element 10 mg / dm ³ .

In a volumetric flask with a capacity of 50 cm ^3, add a dispenser or pipette of 5 cm ^{3 of the} main solution with a mass concentration of the reference element of 10 mg / dm and bring the volume in the flask to the mark with a 1% nitric acid solution.

3 A solution of nitric acid with a mass fraction of 1%.

Measured with a dispenser or pipette 4.7 cm ^{3 of} concentrated nitric acid with a density of 1.415 g / cm ³ are mixed with 495 cm ^{3 of} deionized water, measured by a cylinder. Store in a plastic container.

4 A solution for adjusting the sensitivity of a mass spectrometer with mass concentrations of lithium, magnesium, cobalt, yttrium, cerium, thallium 1 μg / dm ³ .

A tuning solution with mass concentrations of lithium, magnesium, cobalt, yttrium, cerium, thallium 1 μg / dm ^{3 is} used without additional preparation procedures. When using a tuning solution for inductively coupled plasma mass spectrometry (ICP-MS) with a higher content of elements (for example, 10 μg / dm ³ ), a corresponding dilution of it with a 1% solution of nitric acid is carried out. To do this, in a volumetric flask with a capacity of 100 cm, add a dispenser or pipette 10 cm ^{3 of a} tuning solution with a mass concentration of 10 μg / dm and bring the solution to the mark with a 1% solution of nitric acid.

5 Preparation of calibration solutions

Solutions No. 1, No. 2, No. 3, a solution of the internal standard and a solution of 1% nitric acid in the volumes shown in table 2, the dispenser is introduced into the tubes for an automatic sampler with a capacity of 6 cm ³ . Calibration solutions are used freshly prepared.

The calibration graph represents the dependence of the detector signal intensity on the concentration of the detected elements. It is set daily on prepared calibration solutions. A working series consisting of 4-5 solutions is prepared immediately before use by diluting the working solutions of the elements to be determined and the solution containing the indium comparison element (internal standard) with a 1% nitric acid solution.

Determination of the calibration dependence, processing and storage of the calibration results are performed by the spectrometer software.

The proposed method is as follows:

Air sampling of the working area is carried out, aspirating air with a volume of 0.1-1.5 m ³ for 5-15 minutes. through filters of the AFA brand (preferably analytical aerosol filters of the AFA brand: AFA-KhP, AFA-KhA, AFA-VP). To determine the average daily concentrations, 3-4 single samples are taken at regular intervals throughout the day. At the same time, air temperature and atmospheric pressure are recorded at the time of sampling.

Next, the filters are prepared by the method of acid dissolution / extraction in a test tube heater. To do this, the filter is rolled up and placed in a test tube for a test tube heater. 4.0 cm ^{3 of} concentrated nitric acid are added to it. The mixture is incubated for 2.5-3.0 hours at a temperature of + 95 ° C, and then cooled to room temperature. Bring the sample volume to 10 cm with deionized water and mix the contents.

Then 0.5 cm ^{3 of the} prepared sample is introduced into the test tube of the automatic sampler of the mass spectrometer and diluted with 4.45 cm ^{3 of} deionized water.

A 0.05 cm ³ solution of the indium internal standard in deionized water with a mass concentration of 1000 μg / dm ^{3 is} added to the resulting mixture.

In the obtained sample, the concentration of rare-earth metals in the air is determined by inductively coupled plasma mass spectrometry: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, using calibration graph and taking into account the reduction of the air volume selected for analysis to normal conditions. The feed rate of helium in the mass spectrometer, when determined, is 4.5 ml / min, and the feed rate through the mass spectrometer of the prepared sample is 0.4 ml / min.

Below is the rationale for the modes that are claimed in the proposed method:

- at a holding temperature of the mixture of the filter with concentrated nitric acid in the test tube heater less than + 95 ° C, REE losses are possible due to the insufficient degree of extraction of the analyte (opening of the sample) or there will be a need to significantly increase the heating time to extract the analyte; and at temperatures above 95 ° C, thermal damage to the tubes, boiling of nitric acid, and its spraying may occur, which will reduce the measurement accuracy;

- when the exposure time in the test tube heater at this temperature is less than 2.5 hours, the complete REE transition to the solution will not be ensured, and exposure for more than 3 hours is not rational due to the increased analysis time and possible significant evaporation of the sample, leading to excessive air pollution;

- the choice of the amount of concentrated nitric acid 4 cm ³ added to the filter is due to the fact that this volume is sufficient to cover one AFA aerosol filter to extract the analyte from the sample, taking into account the maximum allowable dust absorption of the AFA filters. Adding a larger volume of acid will lead to the dilution of the analyte (the possible receipt of values below the limit of determination of the method) and to irrational consumption of the reagent;

- the dilution of 0.5 cm ^{3 of the} sample is precisely 4.45 cm ^{3 with} deionized water and the addition of 0.05 cm ^{3 of the} internal indium standard (i.e., in a mass ratio of 1:10, respectively) is due to the fact that with this dilution we obtain a solution with a low a concentration of nitric acid (about 7%), just acceptable for introduction into the mass spectrometer, and with this dilution, the sensitivity of the method allows the measurement of the sample;

- when implementing the proposed method, the feed rate of helium in the mass spectrometer should be 4.5 ml / min, and the feed rate through the mass spectrometer of the prepared sample should be 0.4 ml / min. under these conditions, a low level of oxide ions (<1%) is ensured, and matrix and spectral overlays are reduced in the analysis of REEs.

When comparing various methods of sample preparation of filters with the application of a known concentration of rare-earth elements on them, the results are shown in table 3.

The data shown in table 3 show that the use of the proposed method in the preparation of samples of the fuser, i.e. a test tube heater, it is possible to determine all those listed in the inventive method of rare earth elements, because the results obtained correspond to the error established by the proposed method.

To prove the accuracy of the determination of REE by the proposed method and evidence of a high degree of analyte recovery from the selected sample, an experiment was conducted with the determination of REE in dust particles (GSO 9237-2008. Standard sample of the composition of KATEKA coal ash) applied to the filters. GSO is made of fly ash from burning brown coal B-2 and is a powder material with particle sizes of not more than 0.08 mm. For the experiment, filters of this GSO weighing 0.025 g and 0.05 g were applied to the filters, which corresponds to the dust absorption of AFA filters (MUK 4.1.2468). The results of the determination of the REE content, in accordance with the developed method, are presented in table 4.

The analytical degree of analyte recovery during sample preparation should be 90 ± 10% in accordance with GOST R ISO 30011-2017. The data in table 4 show that the degree of REE extraction during sample preparation by the proposed method in the fuser (test tube heater) is from 81 to 100%, which meets the requirements of GOST. For all 15 REEs, the found concentrations correspond to those certified with a determination error not exceeding the error of the proposed methodology.

The content of measured chemical elements in the filters should be minimal, as it can make a significant contribution to the blank sample, the lower limit of the detection of mass concentrations of elements in the air of the working zone depends on the result of the analysis. The calculated detection limits for the various filters are shown in table 5.

The data shown in table 5 show that in all brands of AFA filters, a low REE content, which allows to reach low detection limits when implementing the methodology, and this REE content in a blank sample will not interfere with the determination of low concentrations in the analyzed sample.

Simultaneously with the preparation of the exposed filters, a blank sample and a control (test) sample are prepared. Blank filters are unexposed filters, control breakdown are unexposed filters with the addition of a known amount of the element being determined. Single and control samples are carried out through the entire course of the analysis.

мкг/дм³.The result of determining the element is presented as the average of parallel (at least two) measurements of the analyzed sample solution

μg / dm ³ .

The mass concentration of the analyzed chemical element in the air of the working area (mg / m ³ ) is calculated by the formula:

где

Where

C is the mass concentration of the chemical element in the air of the working zone, mg / m ³ ;

- среднее значение массовой концентрации химического элемента в растворе пробы, мкг/дм³;

- the average value of the mass concentration of the chemical element in the sample solution, μg / dm ³ ;

- среднее значение массовой концентрации химического элемента в растворе холостой пробы, мкг/дм³;

- the average value of the mass concentration of a chemical element in a solution of a blank sample, μg / dm ³ ;

V ₁ is the initial volume of the mineralized sample, dm ³ , V ₁ = 0.01 dm ³ (after processing in a test tube heater);

K is the dilution coefficient (dilution before measurement on a mass spectrometer);

V ₀ - the amount of air sample taken on the analyzed filters, reduced to standard conditions (pressure 760 mm RT. Art., Temperature 20 ° C), dm ³ .

V ₀ calculated by the formula:

где

Where

V is the volume of air drawn out at a temperature t at the sampling location, dm ³ ;

P - atmospheric pressure during sampling, mm. Hg. st .;

t is the air temperature at the time of sampling, ° C.

For the final result take the result of measuring a single sampled air sample.

The experimental data on the example of measurements of samarium by the proposed method are presented in table 6 (the repeatability and intralaboratory precision (intralaboratory reproducibility) of the analytical stage of the procedure are calculated from these measurement results. At the same time, according to the results of the determinations (X _n ) in table 6, the sensitivity of the method (analytical stage from 0.1 μg / DM ³ ).

The data shown in table 6 show that the results obtained by the proposed method have good repeatability (the results differ from each other by 8%), the results are reproducible (differ from each other under conditions of laboratory precision by 9.5%), and it is also visible that the analysis of samples with a low analyte content was carried out and corresponds to the lower boundary of the allowable measurement range indicated in the proposed method.

To calculate the metrological characteristics of the proposed method used the method of "entered - found." Samples were analyzed with the addition of a certain amount of the analyzed component (the additive is 50-350% of the concentration in the working sample), in this case, samarium, to determine the correctness and accuracy of the analysis (relative error). The results of measurements of samarium in the prepared sample with samarium additives are shown in table 7. In this example, the amount of samarium supplement is C = 0.1 μg / dm ³ .

The data given in table 7 show that the value of the additive found corresponds to the amount entered and that the systematic error (correctness indicator) of the method is 12%, and the method error (accuracy indicator of the analytical stage) does not exceed 22%.

During laboratory tests of the proposed method, the following metrological characteristics were established: the measurement range of each of the 15 rare-earth elements in the solution of the analytical sample, in the air of the working area, the values of accuracy, accuracy, repeatability, intralaboratory precision. Table 8 presents the measurement ranges in the sample solution (analytical stage), in atmospheric air, the accuracy rate of the method taking into account the sampling stage, MPC and SHOE for REE.

The data shown in table 8 show that the proposed method allows to accurately determine 15 REE in the concentration range of 0.000007-100 mg / m ³ (depending on the element) in the air of the working area. The sensitivity of the method makes it possible to detect low concentrations to obtain reliable results of the ultra-low impacts of chemical elements used in industry, and high concentrations, which allow one to detect excess of standard indicators of REE content in the air of the working area.

Table 9 shows the conditions for analysis on an Agilent 7500 _cx brand inductively coupled plasma mass spectrometer in the reaction mode.

Thus, the proposed method for determining the concentration of 15 REE in the air of the working zone is characterized by the following indicators that exceed all known methods:

- allows you to determine these REE in a wide range of air samples from 0.1 to 1.5 m ³ with the same accuracy and reliability;

- characterized by the ability to determine 15 REE from one sample in a concentration range of 0.000007-100 mg / m ³ (depending on the element) with an accuracy of 21 to 23%. Moreover, the reliability is not less than p = 0.95;

- the proposed method is simple to perform in comparison with the known methods, minimal labor.

Note: MPC - maximum permissible concentration;

SHOE - indicative safe exposure levels

Note: ngo is below the detection limit of the method.

Claims (2)

1. A method for determining the concentration of rare earth elements: lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, in the air of the working zone by inductively coupled plasma mass spectrometry characterized in that produce a selection by drawing air working area of the test air sample volume of 0.1-1.5 m ³ via aerosol filter analytical for 5-15 minutes, fixed air temperature and atmospheric pressure at the sample point selection, PEFC Air sampling filter is decomposed in test-tube heater, for this filter is placed in a test-tube heater tube, was added thereto 4.0 cm ³ of concentrated nitric acid, the mixture was incubated for 2.5-3.0 hours at a temperature of + 95 ° C cooled to room temperature, the sample volume was adjusted with deionized water to 10 cm ^3, the content was stirred, and then 0.5 cm ³ of the prepared sample is introduced into autosampler vial mass spectrometer, it was diluted with 4.45 cm ³ of deionized water was added to give w mixture of 0.05 ^cm3 indium internal standard solution in deionised water to a mass concentration of 1000 mcg / dm ³ and in the obtained sample by mass spectrometry with inductively coupled plasma, the concentration of the rare earth elements: lanthanum, cerium, praseodymium, neodymium, samarium, europium , gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, using the calibration graph and taking into account the reduction of the air volume selected for analysis to normal conditions, while the flow rate of helium in mass spec the trometer is 4.5 ml / min, and the feed rate through the mass spectrometer of the prepared sample is 0.4 ml / min. 2. The method according to p. 1, characterized in that as an analytical aerosol filter using filters brand AFA.