The method of sampling and sample treatment for the determination of surface contamination by metallic mercury and its compounds

 

The invention relates to analytical chemistry, in particular, to methods of sampling and sample handling mercury method Polezhaev. In the way take samples for mercury tampons weighing 30050 mg with square 100-150 cm2moistened with a solution of iodine in potassium iodide, and subsequent reaction with a compound solution with formation of a colored complex of Cu2(HgI4). Sampling from surfaces provide not less than two times two cotton swabs. The first swab weighing 30050 mg ml absorption solution and wipe the analyzed surface. The second dry swab with mass 10020 mg from the surface collect the remains of the absorbing solution. Then both swab is transferred into a test tube with absorbing solution and fray tampons in the solution at a temperature of 35-40C. Pressed tampons treated similarly to negative reactions to mercury with summation of results. To separate the dirt from the absorption solution centrifuged at 3000 rpm for 3 minutes. The method provides for the selection and analysis of samples of mercury on the surfaces. 6 Il., table 2.

Invented Jeeva.

Currently known and described the following methods of sampling and sample handling mercury method Polezhaeva from different environments, which are analogues of the invention.

a) Determination of mercury in air method Polezhaeva [1].

The essence of the method lies in the interaction of mercury vapor with iodine in the presence of KI with the formation of complex compounds K2(HgI4)

and its subsequent interaction with a solution of sulphate of copper with the formation of the colored complex Cu2(HgI4). Mercury define colorimetrically the pink color against a white mist Si2. The sensitivity of the method is 0.01 mg/m3.

The reagents used in this method are prepared as follows:

- iodine, crystal vozokany (sublimation of crystalline iodine is carried out on electric tile in a glass beaker, which contribute about 10 grams of iodine.) The glass rose watch glass or Petri dish, which is placed soaked in cold water wool. In the process of sublimation pair iodine deposited on the cold surface, forming a purple crystals. After sublimation of the crystals scraped in tube. Who is th solution;

absorptive solution (dissolve 2.5 g vogognano iodine and 30 grams of potassium iodide in a little water and bring the volume to 1 liter with distilled water);

- sodium sulfite Na2SO3·7H2About 3 N. solution;

- chloride of copper ul2·2H2About 7% solution or copper sulfate CuSO4·5H2Oh, 10% solution;

- reactive solution in the measuring cylinder and make 1 volume of 10% aqueous solution of copper sulfate and 5 volumes 3 n solution of sodium sulfite). The mixture was shaken to dissolve the precipitate. The solution was prepared before analysis);

- standard solution of mercury (dissolved 0,0135 g of mercury chloride in 100 ml of absorbing solution). Then 1 ml of the prepared solution was diluted with 100 ml of absorbing solution (standard solution contains 1 ml 1 ug-ion mercury Hg+2);

Sampling for analysis is as follows. 30-40 l of the investigated air at a rate of 40 l/h stretch through two series-connected adsorption device Polezhaeva, containing 2 ml of absorbing solution (Fig.1). In the process of sampling is the release of iodine from the solution, and the color saturation of the solution becomes pale. Restore the original color of the solution is performed 0 the ASCI. Ash iodine is especially great, if you analyze the heated air.

Determination of mercury in the sample is performed as follows. In centrifuge tubes make 1 ml of absorbing solution from each device, add 1-2 drops of 0.1 n iodine solution to restore the original color absorbing solution and injected 0.8 ml of the reactive solution. The liquid shake, leave for 15-20 minutes before the deposition of sediment, then the color of the latter compared to the standard scale (Fig.2), (PL. 1). It is possible doubling of all components of the reaction volume.

The calculation of the concentration of mercury in the air is realized by the formula

where

V is the total volume of the investigated solution, ml;

and the number of substances found in the analyzed volume of solution, µg;

V1- researched volume of solution taken for analysis, ml;

V0- researched volume of air, l

This method is only applicable for the analysis of air. The difference between the proposed method and similar enclosed in a fundamentally different way of sampling.

So the actual sampling is performed by wiping a contaminated surface of the wet and dry swabs. For ustralia increase the degree of extraction of mercury from the sample processing samples is carried out at elevated temperatures (35-40C). To ensure the reliability of tampons and the surface is processed to a negative reaction to mercury.

b) Another analogue of the invention is the determination of mercury in protective clothing [3]. Soaking the analyzed service by this method is carried out in 5 litres of absorbing solution. Analyses of 0.1 ml of the obtained extract. The disadvantage of this method is the absence of any clean-up absorbent solution from dirt, which can distort the results of the analysis. In addition, clothing can contain mercury in metallic form, which in a single processing absorptive solution does not eject fully.

The proposed method in addition to the actual sampling is characterized by the presence of multiple processing operations of the investigated surface and means sampling - cotton swabs, and centrifugation absorbing solution with the aim of separating the dirt.

in Another analogue of the invention is a method for the determination of mercury in various materials [2].

The way and the two previous ones, is based on the extraction of mercury from materials with a solution of iodine in iodide of potassium, however, the actual recovery of mercury is achieved by heating the sample thermal desorption mouth is recorded at different depths (2-6 cm). Scraping from the walls, floor and various items taken from the surface (5-10 cm2).

The sample is crushed in a mortar, wood is cut into small pieces. For analysis of 5-10 g of sample is placed in a flask with a glass stopper, pour 0.5% solution of iodine so as to cover its surface, and leave for 2-3 hours, occasionally shaking. If iodine is discolored, add small portions 8% solution of iodine to stop discoloration. Then, the sample is filtered through a paper filter, pre-washed with 5% solution of iodine and distilled water. Measure the volume of filtrate and determine the mercury ion. In those cases, when the sample admixed extraneous colored compound, which complicates colorimetrically, removing mercury from the sample is carried out by thermal desorption. A portion of the ground material is placed in a glass tube and heated to about 150With stretch through it about 20 liters of pure mercury air. Emitted when this mercury vapor absorb 10 ml of absorbing solution for mercury.

Previously conducted audit experience, which through a tube put 20 litres of clean air in the adsorption unit with 10 ml of adsorption races of the tube; 1 ml of the sample was adjusted to 5 ml of absorbing solution. At the same time preparing the schedule of standards.

If the sample is stained less intensely than the solutions in the scale, then add 1-2 drops of an 8% aqueous solution of iodine to the adjustment of colors. Then in a test tube scale and sample add 1 ml of compound solution (10% uSO4+Na2SO3(1:5)). After 15-20 min after complete deposition of sediment in the bottom of the tubes compare the colour intensity of sediment rating standards.

Mercury X (mg/g of material) is calculated by the formula

where a is the amount of mercury in the analyzed sample volume, ug;

V - volume of sample taken for analysis, ml;

V0- the total volume of sample, ml;

g - hitch, ,

This method is analogous to the invention, and it has the same differences from the proposed method: sampling new and different in the analog argues that the mercury in the sample after contact with a solution of iodine in potassium iodide completely removed. However, this is not the case. In experiments it is shown that for reliable extraction of mercury requires multiple processing samples. Given the methodology, the exposure time 3 hours very little. In the analysis of such samples as wood, plastics, scrapings is chodenji the sample in the absorption solution about a day. To eliminate the interfering influence of fine samples from the absorption solution in the prototype is used, the filtering method. However, in this case the results of the analysis can be severely distorted due to the dilution of the sample on the filter. In the proposed method, cleaning is carried out by centrifuging.

The prototype of the invention is the Method of measurement of mass concentration of mercury in the filtrate swabs from surfaces on the mercury analyzer RA-915+ with the prefix RP-91” [4].

In the prototype, the sampling is carried out using the method Polezhaeva cotton swab weighing 300 mg soaked in the absorption solution with an area of 150 cm2. The analyzed surface is wiped with a cotton swab, the swab is then filled with a volume of absorbing solution 5 ml, the swab is pressed, the resulting solution is filtered on a paper filter. Subsequent processing of the results is carried out by cold vapor analyzer RA-915+ with the prefix RP-91. The main disadvantages of the method of the prototype are:

- treatment swab surfaces is carried out only once. This is due to the use of this method for analysis of zagryaznennosti only up to 0.05 ág of mercury in the sample (the sample taken different lamps. In other cases, contamination of the way will make obviously incorrect result;

- separation of dirt from the absorbing solution by filtration on a filter, resulting in losses of mercury to the filter;

collect the remaining part of the absorbing solution in the area of 150 cm is not performed. Meanwhile, it remains up to 20-30% solution, which contains mercury, which is lost.

The invention consists in the combination of essential features that are in a causal relationship and achieve the claimed result: selection and analysis of samples of mercury on the surfaces of:

- sampling is performed in two cotton swabs. The first swab weighing 30050 mg wetted absorbent solution slightly and pressed them with tweezers wiped investigated the specific surface area, after which the swab is transferred into a test tube with absorbing solution. The second dry swab lighter weight 10020 mg with the same surface collected the remains of the absorbing solution. After collection, the swab is placed in the same tube. Weight tampons optimal for the size of the area of 100-150 cm2,with which otber the flax solution carefully fray with a glass rod, and then wrung out at the side surface of the tubes and transferred to another tube for re-analysis;

- centrifuging the contents of the tubes at 3000 rpm for 3 minutes. Taking swabs ("strokes") from the surface is always accompanied by contamination of the swabs with the absorption solution in contact with the test surface. In some cases, cotton wool, moistened absorbent solution can be strongly contaminated by sand, dust, soot, old paint, etc. After spinning wool absorbing solution becomes opaque, changes the color and contains a suspension (Fig.3). When conducting the actual analysis of the resulting white precipitate of iodide of copper mixes with dirt, and get any results at all. For separating dirt from a solution are two methods: filtering and proposed - centrifugation.

The filtering method is that through pre-moistened absorbent solution filter is filtering investigated the absorption solution. However, in this case the distortion of the concentration in the sample due to the loss and dilution of mercury on the filter.

Centrifuging method allows for easy and lossless separate € absorbing solution. After centrifugation there is a restoration of the original color absorbing solution. At high accelerations and time of centrifugation for about 10 minutes caking sludge is such that even when it is draining into another test tube "resuspension" sediment does not occur. While centrifuged to the bottom of the seats centrifuge must be wool. If this is not done, the centrifuge can break the bottom of the tube.

- processing of swabs is carried out several times to negative reactions to mercury with summation of results;

- processing of a single sample surface contaminated with mercury, is at least two times;

with the aim of reducing the number of processing cycles for tampons removing mercury from tampons absorbing solution is carried out at a temperature of 35-40C. In this case, achieving a higher degree of extraction from swabs mercury absorbent solution in a single treatment. At higher temperatures 50C and above, there is a decrease in the intensity of staining of the complex Cu2(HgI4), which leads to a distortion of the results of the analysis.

To assess the degree of contamination of the surface img.russianpatents.com/chr/215.gif">10). For this purpose, a stencil is made, the boundaries of which are applied on the surface a simple pencil (Fig.4 ).

Application of absorption solution on this surface is carried out with tweezers using a cotton swab weighing approximately 300 mg. For this cotton swab moistened in the absorption solution, slightly pressed and the surface wiped with parallel first horizontal and then vertical movements. After that, the swab is placed in a test tube and filled with 2 ml of absorbing solution (Fig.5).

Collecting the remaining part of the absorbing solution is second with a dry cotton swab weighing approximately 100 mg After collecting the absorption solution swab is placed in the same tube. Both swab carefully fray with a glass rod in the solution, then do push-UPS on the side surface of the tube and removed from it (for possible re-processing) (Fig.6).

Contamination of surfaces with drip Strait mercury is large enough. Therefore, the range of scales for a rough estimation of the contamination increases. To obtain sufficiently reliable data is built on two scales: approximate and exact. To build orientirovka table 2. It has a "step" concentrations of approximately 10 mg. The exact scale is built after a rough estimation of the level of serrazanetti with an increment of 0.2 ug.

The possibility of implementation of the method is confirmed by the following examples.

Example 1

In a glass jar was a plate made of polyethylene with an area of 100 cm2who was in contact with the mercury vapor within 5 days at a temperature of 20C.

After that she had made two consecutive flushing tampons on the proposed method (the first swab is rubbed and wet the surface of the plastic plate and the second wiping the surface dry).

After sampling mercury both swabs were placed in the adsorption solution and warmed up for 1 minute, after which the cotton is pressed, the solution was ofcentrifugal and poured absorbing solution again.

As a result of the experience of the first flush two swabs gave a positive result is the presence of mercury approximately 1 μg per sample (0.02 μg/cm). Reprocessed wool absorbing solution showed the presence of mercury for about 0.3 ág per sample. The third treatment was negative.

The second flush with the surface gave followed by the third wash was negative already at the first treatment pad. Thus, the total contamination of the surface was 1 µg + 0.3 ág + 0.3 ug = 1.6 ĩg on the surface 100 cm2. A significant increase in contamination with increasing time of contact of the polyethylene plate with mercury vapor to 10 days did not happen. The average level of contamination remained the same.

Example 2

The purpose of the experiment is to identify the mercury contamination of the surface of the glass at high concentrations of mercury.

For this moistened absorbent solution swab, and then dry swab rubbed the glass surface S=100 cm2after passing through the surface of a drop of mercury.

To assess the degree of contamination of the first flush two swabs were processed absorbing solution in accordance with the claimed method.

The results:

1 processing tampons - mercury 20 ág per sample;

2 processing tampons - mercury 20 ág per sample;

3 processing tampons - mercury concentration of 10 ág per sample;

4 processing tampons - mercury 8 ág per sample;

5 processing tampons - mercury 6 ág per sample;

6 processing tampons - mercury 3-4 ág per sample;

7 handling tampons - mercury 1 ág per sample;

8 obrabotkata

the results:

1 processing tampons - mercury 6 ág per sample;

2 processing tampons - mercury 3 ág per sample;

3 processing tampons - the mercury content of 1.5 ág per sample;

4 processing tampons - mercury 0.2 ág per sample;

5 processing tampons - negative.

Processing the third flush two cotton swabs gave the following results:

1 the mercury content of 1.5 ág per sample;

2 processing - the mercury content of 0.3 ág per sample;

3 processing - negative.

Processing the fourth washings gave a negative result.

Thus, when using the method of taking swabs from surfaces with large contaminants mercury swabs should be processed to obtain a negative result on mercury.

The total contamination of the mercury surface amounted to 81.7 ág per sample(20+20+10+8+6+4+1+0,2+6+3+1,5+0,2+1,5+0,3).

Sources of information

1. Peregud E. A. and other Chemical analysis of the air of industrial enterprises. - L.: Chemistry, 1973

2. Peregud E. A. Chemical analysis of air. - L.: Chemistry, 1976

3. Mercury. Normative and methodological documents. The Handbook. - SPb., 1991, Appendix 3, page 62.

4. Mercury. Normative and methodological documents. The Handbook. - SPb., 1991, page 170.

50) mg with square 100-150 cm2,moistened with a solution of iodine in potassium iodide, and subsequent reaction with a compound solution with formation of a colored complex of Cu2(HgI4), characterized in that the sampling of surfaces carry out at least two times two cotton swabs: the first swab mass (30050) mg ml absorption solution and wipe the analyzed surface, the second dry swab mass (10020) mg from the surface is collected the remains of the absorbing solution, after which both swab is transferred into a test tube with absorbing solution, the chafing of tampons in the solution is carried out at a temperature of 35-40With, pressed tampons treated similarly to negative reactions to mercury with summation of results and to separate the dirt from the absorption solution centrifuged at 3000 rpm for 3 minutes

 

Same patents:

The invention relates to meteorology and can be used to determine the parameters of contamination by measuring the impurities deposited on the surface of the filter

The invention relates to the field of veterinary medicine

The invention relates to the field of veterinary medicine

The invention relates to research on the assessment of corrosion on the internal surface of the pipeline and can be used in chemical, oil and gas industry

The invention relates to mechanical engineering and can be used in electro-production in the manufacture of parts from a strip of molybdenum

The invention relates to sampling, moving through the pipeline liquids, and can be used in any industry to control physical, chemical, and other properties of the fluids that require the selection of representative samples

The invention relates to sampling, moving through the pipeline liquids, and can be used in any industry to control physical, chemical, and other properties of the fluids that require the selection of representative samples

The invention relates to the field of veterinary medicine

The invention relates to a technology for separation and purification of complex liquid mixtures and can be used for dosing reagents in liquid chromatography

FIELD: automatical aids for sampling liquids.

SUBSTANCE: system for sampling and delivering filtrate has filter submerged into tested medium and connected with collecting tank and vacuum pressure source which is connected with top hole of collecting tank by means of pneumatic pipe. System has sample receiving tank connected with collecting tank and control unit which has first output to be connected with vacuum pressure source. Collecting tank has two separated chambers - washing chamber and dispatching chamber. Lower hole of washing chamber has to be lower hole of collecting tank and side hole of dispatching chamber has to be side hole of collecting tank. Floating valve is installed inside washing chamber to shut off lower and top holes. Filter is connected with lower hole of collecting tank through sampling pipe. Side hole of collecting tank is connected with lower hole of tank for receiving samples through sampling pipe. Flow-type sensor and check valve are installed inside transportation pipe. Output of flow-type sensor is connected with input of control unit; second output of control unit is connected with control input of analyzer.

EFFECT: improved precision of measurement of sample ion composition; prolonged service life of filter.

1 cl, 1 dwg

FIELD: hydrology; hydrobiology.

SUBSTANCE: device for simultaneous sampling of water samples taken from layers of water laying close to each other, has set of cylinders with pistons disposed onto carrying frame. End parts of all cylinders are hermetically tied with multiplier, which is connected with pump by means of hose pipe. Front edges of all cylinders are provided with beaks having entrance holes for taking water samples. Pistons moves inside cylinders due to hydraulic tie-rod. Space inside hose-pipe, multiplier and end parts of all cylinders is filled with water to avoid corrosion.

EFFECT: improved reliability of efficiency of operation; better protection corrosion.

FIELD: investigating or analyzing materials.

SUBSTANCE: device has cylindrical housing, heater, clamp, pump for pumping water to be investigated, and valve for insulation of the sample from ambient water. The device is provided with a unit which has an assembly of cells with microbiological filters connected in parallel. The diameters of the cells are different. The device has additional heater mounted in the top part of the housing and additional valve. The cell assembly is interposed between the valves.

EFFECT: enhanced reliability of sampling.

1 dwg

FIELD: investigating or analyzing materials.

SUBSTANCE: device has cylindrical housing, heater, clamp, pump for pumping water to be investigated, and valve for insulation of the sample from ambient water. The device is provided with a unit which has an assembly of cells with microbiological filters connected in parallel. The diameters of the cells are different. The device has additional heater mounted in the top part of the housing and additional valve. The cell assembly is interposed between the valves.

EFFECT: enhanced reliability of sampling.

1 dwg

FIELD: investigating or analyzing materials.

SUBSTANCE: sampling device has sampler, changeable batching member which is made separately from the sampler, housing, and wind-protection device. The wind-protection device is made of porous diaphragm mounted in the base of the housing and overlaps it. The sampler is mounted to provide the distance between the inlet port of the sampler and diaphragm to be 0.1D<L<0.3D, where D is the diameter of diaphragm and L is the distance between the inlet port of the sampler and diaphragm.

EFFECT: improved design.

3 cl, 1 dwg

FIELD: test technology.

SUBSTANCE: sample for testing porous materials by means of shock compression is made in form of a disc with flat parallel bases and cone side surface. Diameters of bases of disc relate as (7-8):1. Thickness of sample equals to (0,15-0,2) diameter of larger base.

EFFECT: reduced number of tests; improved precision.

2 dwg

FIELD: meteorology.

SUBSTANCE: device has sampling cylinder provided with cutting ring with teeth, piston with pusher, cutting members secured to the inner side of the ring, and cover with central threaded opening for the pusher made of a screw. The cover and pusher are provided with handles.

EFFECT: enhanced convenience of sampling snow.

4 cl, 5 dwg

FIELD: analyzing and/or investigating of materials.

SUBSTANCE: method comprises setting the sampling member and means for measuring the flow parameters into the pipeline, pumping a part of the flow through the sampling member, and determining the parameters of the flow.

EFFECT: enhanced reliability of sampling.

1 dwg, 1 tbl

FIELD: investigating or analyzing materials.

SUBSTANCE: method comprises setting the sampling member into the pipeline, separating the branch with inhomogeneous distribution of inclusions upstream of the sampling, directing the branch to the mixer for the intensive homogenizing, combining the flow branches, and sampling the combined flow. The device has sampling member, by-pass pipeline for branching the flow, and mixer. The mixer is mounted on the horizontal section of the pipeline between the inlet of the by-pass pipeline and its outlet for homogenizing the flow branch, which does not flow through the by-pass pipeline.

EFFECT: enhanced reliability of sampling.

2 cl, 4 dwg, 1 tbl

FIELD: oil industry.

SUBSTANCE: device has hollow body which is a fragment of force pipeline at vertically placed portion of mouth armature. Tool for controlling flow of multi-component gas-liquid substance is made in form of valve, connected to rotary support. Sample chamber is a ring-shaped hollow in hollow body, placed at same level with valve and connected at inlet to flow of multi-component gas-liquid substance through extracting channels, made on hollow body. Extracting channels are made in form of side slits, positioned symmetrically relatively to valve rotation axis. Ring-shaped hollow on hollow body is connected at outlet to locking tool, mounted at extension of valve shaft and made in form of sample-taking valve. Valve shaft and sample-taking valve are interconnected through hollow intermediate shaft. Sample-taking valve is placed in the body of locking tool with possible reciprocal movement. Valve shaft and hollow intermediate shaft are interconnected with possible mutual rotation for a quarter of one turn.

EFFECT: simplified construction and maintenance, higher quality.

4 dwg

Up!