GOST 27981.5-88

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  ГОСТ 27981.5-88

GOST 27981.5−88 Copper of high purity. Photometric methods of analysis

GOST 27981.5−88

Group B59

STATE STANDARD OF THE USSR

HIGH PURITY COPPER

Photometric methods of analysis

Copper of high purity. Methods of photometric analysis

AXTU 1709

Valid from 01.01.1990
until 01.01.2000*
_______________________________
* Expiration removed
Protocol N 7−95 Interstate Council
for standardization, Metrology and certification
(IUS N 11, 1995). — Note the manufacturer’s database.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

PERFORMERS:

B. M. Rogov, E. N. Gazalov, I. Swan, L. N. Shipanova, V. P. Krasnonosov, L. N. Vasilyeva, N. And. Molostvov

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 22.12.88 N 4443

3. The term of the first check — 1994

The frequency of inspection — 5 years

4. The standard complies with international standards: ISO 1810 in the determination of Nickel; ISO 2543 in the determination of manganese; ISO 3220 in the determination of arsenic; ISO 4741 in terms of determining phosphorus; ISO 5959 in the determination of bismuth

5. INTRODUCED FOR THE FIRST TIME

6. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard establishes photometric methods for determination of components in high purity copper, are given in table.1.

Table 1

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis and security requirements when performing the analysis according to GOST 27981.0.

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF BISMUTH

The method is based on measuring the optical density at a wavelength of 420−450 nm painted godenovo complex of bismuth, formed in hydrochloric acid solution in the presence of tartaric acid and reducing agent.

Bismuth is pre-allocated to the iron hydroxide.

2.1. Equipment, reagents, solutions

Spectrophotometer or photoelectrocolorimeter of any type.

Mechanical scrambler of any type.

Laboratory scales analytical any type of the 2nd accuracy class with the error of weighing according to GOST 24104*.
_______________
* On the territory of the Russian Federation GOST 24104−2001, here and hereafter. — Note the manufacturer’s database

Glasses N-1−250, H-1−100 TCS according to GOST 25336.

Flasks conical KN-2−250 TCS according to GOST 25336.

The crater tapered V-36−80 TC GOST 25336.

Volumetric flasks 2−50−2, 2−500−2, 2−1000−2 according GOST 1770.

Pipette 2−2-1, 2−2-5, 2−2-50, 6−2-5, 6−2-10 according to GOST 20292*.
________________
* On the territory of the Russian Federation there are 29169−91 GOST, GOST 29227−91−29229−91 GOST, GOST 29251−91-GOST 29253−91, here and hereafter. — Note the manufacturer’s database.

Nitric acid according to GOST 4461 or nitric acid high purity according to GOST 11125, diluted 1:1.

Hydrochloric acid according to GOST 3118, diluted 1:1.

Tartaric acid according to GOST 5817, a solution of 250 g/DM.

Ammonia water according to GOST 3760, solutions of 1:1, 1:99.

Ascorbic acid, freshly prepared solution 50 g/DM.

The iron powder according to GOST 9849, a solution of 10 g/DM, a sample of iron with a mass of 1.0 g was dissolved with heating in 10−15 cmof hydrochloric acid. After cooling, the solution was placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

Potassium iodide according to GOST 4232, a freshly prepared solution of 200 g/DM.

Tin dichloride, the solution 200 g/lin hydrochloric acid (1:1).

Bismuth GOST 10928*.
______________
* On the territory of the Russian Federation GOST 10928−90. — Note the manufacturer’s database.

2.2. Preparations for the analysis

2.2.1. Preparation of standard solutions

Solution a: a sample of bismuth by weight 0,100 g dissolved in 5−10 cmof nitric acid, heated to remove oxides of nitrogen. Cooled and placed in a measuring flask with volume capacity of 1000 cm, 65 cm pour thenitric acid and adjusted with water marks Yes.

1 cmof solution A contains 0.1 mg of bismuth.

Solution B: take 25 cmof solution A and placed in a volumetric flask with a capacity of 250 cm, 5 cm pour thenitric acid and adjusted to the mark with water.

1 cmof a solution contains 0.01 mg of bismuth. The solution is ready for use within 5

h

2.2.2. Construction of calibration curve

In a conical flask with a capacity of 250 cmis placed 0,0; 1,0; 2,0; 3,0; 4,0 and 5,0 cmstandard solution B, which corresponds to 0,0; 0,01; 0,02; 0,03; 0,04 and 0,05 mg of bismuth, and added 5 cmof nitric acid, 20 cmof hydrochloric acid. The solutions were heated and evaporated to a volume of 3−5 cm. Then pour 5 cmof a solution of iron, 100−120 cmof water, heated to a temperature of 60−70 °C and poured ammonia to transition copper ammonium complex and then another 5 cm. Heating was continued for 5−7 min and leave the solution to the coagulation of sludge in a warm place plate.

The precipitate of hydroxides is filtered on a loose filter, and washed 3−5 times with hot ammonia diluted 1:99. The precipitate from the filter washed into the flask in which the precipitation was carried out, and dissolved in 15−20 cmof hot hydrochloric acid, diluted 1:1. Dilute the resulting solution with water to a volume of 80−100 cmand re-precipitated hydroxides with ammonia. The precipitate was filtered on the same filter and washed 3−4 times with hot ammonia diluted 1:99. Funnel with a filter placed over the flask in which the precipitation was carried out, and dissolve the residue in 10−15 cmof hot hydrochloric acid, diluted 1:1, the filter is washed 2−3 times with hot water. The filter is discarded. The filtrate is evaporated to a volume of 10 cm, after cooling it is placed in a volumetric flask with a capacity of 25 cm, up to 4 cmof tartaric acid solution, 5 cmof a solution of potassium iodide, 1.0−1.5 cm.of ascorbic acid solution and adjusted to the mark with water.

Measure the optical density of the solutions after 10−15 min in the spectrophotometer or photoelectrocolorimeter at a wavelength of 420−450 nm in a cuvette with an optimum thickness of the layer. Solution comparison is water.

According to the obtained values of optical densities and corresponding concentrations of bismuth build the calibration

yy schedule.

2.3. Analysis

A sample of copper with a mass of 2,000 g were placed in a glass with a capacity of 400 cm, 25−30 cm pourednitric acid and covered with glass. Left without heating until the cessation of the violent reaction of the allocation of nitrogen oxides. Then remove the glass, wash it with water above the glass, add 20−25 cmof hydrochloric acid and evaporated solution when heated to a volume of 3−5 cm.

Poured into a glass of 80−100 cmwater and 5 cmof a solution of iron. Heat and then continue the analysis as described in section 2.2.2.

Mass of bismuth determined by the calibration schedule.

2.4. Processing of the results

2.4.1. Mass fraction of bismuth () in percent is calculated by the formula

,

where is the mass of bismuth in the solution of the sample, was found in the calibration schedule, mcg;

 — the mass of bismuth in the solution in the reference experiment, µg;

 — weight of copper,

2.4.2. Allowable absolute differences of the results of two parallel measurements at a confidence level =0.95 is used to analyze a sample of copper (the rate of convergence) and the results of the analysis of the same samples obtained in two laboratories and one reference laboratory, but under different conditions (a measure of reproducibility) shall not exceed the values given in table.2.

Table 2

2.4.3. Control of the correctness of the results of the analysis carried out on standard samples of composition of copper.

The results of the analysis of the sample is considered correct if played mass fraction of component in the standard sample differs from the certified characteristics are not more than the value of 0.71, is given in the method of analysis.

2.4.4. Allowed to control the correctness of the results of the analysis carried out by the method of additions. The mass of the additive (the volume of a standard solution) is chosen so that the analytical signal of the designated component is increased 2−3 times compared to the analytical signal in the absence of additives.

The tests are considered valid if the value found additives different from the entered values were no more than where and  — the permissible discrepancy of the two results of the analysis for the sample and the sample with the additive.

For the final result of the analysis of samples take result of meeting the requirements of paragraphs.2.4.2−2.4.4.

3. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF MANGANESE

The method is based on measuring the optical density of the colored complex compounds pneumococcal of manganese at a wavelength of 530 nm.

3.1. Equipment, reagents, solutions

Spectrophotometer or photoelectrocolorimeter of any type.

Volumetric flasks 2−100 (1000)-2 GOST 1770.

Flask conical KN-1−250−14/23 TC GOST 25336.

Pipette 7−2-10 according to GOST 20292.

Nitric acid according to GOST 4461 or nitric acid high purity according to GOST 11125 and diluted 1:1, 1:3.

Sulfuric acid according to GOST 4204, diluted 1:4.

Potassium cognately, a solution of 50 g/lin nitric acid, diluted 1:3.

Sodium atomistically according to GOST 4197, solution 20 g/lfreshly prepared.

Manganese metal according to GOST 6008*.
______________
* On the territory of the Russian Federation GOST 6008−90. — Note the manufacturer’s database.

3.2. Preparation for assay

3.2.1. Preparation of standard solutions

Solution a: a portion of the manganese weight 0,100 g dissolved in 10−15 cmof nitric acid, diluted 1:1, when heated to remove oxides of nitrogen. Cool, put in a measuring flask with volume capacity of 1000 cmand was adjusted to the mark with water.

1 cmof solution A contains 0.1 mg of manganese.

Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cm, add 1 cmof nitric acid, diluted 1:1, and adjusted to the mark with water.

1 cmof a solution contains 0.01 mg of manganese.

Solution: 50 cmof a solution is placed in a volumetric flask with a capacity of 100 cm, pour 0.5 cmof nitric acid, diluted 1:1, and adjusted to the mark with water.

1 cmof the solution contains 0.005 mg Marg

ANCA.

3.2.2. Construction of calibration curve

In glasses with a capacity of 250 cmare placed sequentially 0,0; 1,0; 2,0; 5,0 cmstandard solution and 1,0; 2,0, 3,0; 4,0 and 5,0 cmstandard solution B, which corresponds to 0,0; 0,005; 0,010; 0,025; 0,100, 0,200; 0,300; 0,400; 0,500 mg of manganese. In all the cups add water to a volume of 20 cm, then boiled for 5 min.

In the boiling solution was injected 5 cmof a solution of potassium jednolitego and continue boiling for another 5 min. Then the beaker placed on a boiling water bath and kept for 20 min.

After cooling, the solution was placed in a volumetric flask with a capacity of 50 cmand was adjusted to the mark with water (stock solution).

Absorbance measured on the spectrophotometer at a wavelength of 530 nm or photoelectrocolorimeter with a filter having the wavelength corresponding to maximum light transmission at ranges from 520 to 540 nm in a cuvette with a layer thickness of 20 or 30 mm.

Solution comparison is part of the basic sample solution, in which the pneumococcal manganese reduced to bivalent by adding 1−2 drops of solution of sodium attestatio.

For poluchennym values of optical density of solutions and their corresponding concentrations of manganese build a calibration curve in rectangular coordinates.

3.3. Analysis

A sample of copper with a mass of 2,000 g (at a mass fraction of manganese from 0,0002 to 0,001%) or 1,000 g (with mass fraction of manganese from 0.001 to 0.005%) were placed in a glass (or flask) with a capacity of 250 cm, 20−25 cm pourednitric acid and boil to remove oxides of nitrogen and dissolving the sample. The solution is evaporated to half and then continue as described in claim 3.2.2.

The mass of manganese determined by the calibration schedule.

3.4. Processing of the results

3.4.1. Mass fraction of manganese () in percent is calculated by the formula

,

where is the mass of manganese in the solution of the sample, was found in the calibration graphics mg;

 — the mass of manganese in solution in the reference experiment, mg;

 — weight of copper,

3.4.2. Allowable absolute discrepancies in the results of two parallel determinations for sample analysis at a confidence level =0.95 is (the rate of convergence) and the results of the analysis of the same samples obtained in two laboratories and one reference laboratory, but under different conditions (a measure of reproducibility) shall not exceed the values given in table.3.

Table 3

3.4.3. Control of the correctness of the results of the analysis carried out in accordance with PP.2.4.3, 2.4.4.

4. SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF COBALT

The method is based on measuring the optical density at a wavelength of 410 nm painted cobalt compounds 1 nitroso-2-naphthol after extraction with toluene, and his prior separation of metallic copper on aluminium.

4.1 Equipment, reagents, solutions

A spectrophotometer of any type.

Scales laboratory analytical type VLR, or equivalent, of the 2nd accuracy class with the error of weighing according to GOST 24104.

Flask conical KN-2−250−18 TCS GOST 25336.

Glass N-1−100 (50) TCS according to GOST 25336.

Funnel separating VD-1−250 (100) TC GOST 25336.

Cylinder 1−5 (10) according GOST 1770.

Volumetric flasks 2−100 (500)-2 GOST 1770.

Pipette 5−2-1 (2) according to GOST 20292.

Pipette 7−2-5 (10) according to GOST 20292.

Glass coverslip.

Nitric acid according to GOST 4461 (boiled to remove oxides of nitrogen), diluted 1:1.

Hydrochloric acid according to GOST 3118 and a solution of 4 mol/DM.

Acetic acid according to GOST 61.

Citric acid according to GOST 3652, a solution of 250 g/DM.

Potassium hydroxide according to GOST 24363, solutions of 5 and 50 g/DM.

Aluminium granulated high purity.

Chloroform according to GOST 20015*.
______________
* On the territory of the Russian Federation GOST 20015−88, here and hereafter. — Note the manufacturer’s database.

Toluene according to GOST 5789, H. h

1 nitroso-2-naphthol according to GOST 7756, solution 0,5 g/DM: a portion of the reagent a mass of 0.25 g is dissolved in 50 cmof potassium hydroxide solution 50 g/DM, placed in a volumetric flask with a capacity of 500 cm, pour 100 cmof acetic acid, diluted to the mark with water and mix.

Hydrogen peroxide according to GOST 10929 (stable product) .

Cobalt GOST 123*.
______________
* On the territory of the Russian Federation GOST 123−98 (01.07.2009 valid GOST 123−2008). — Note the manufacturer’s database.

Copper according to GOST 859* not containing cobalt.
______________
* On the territory of the Russian Federation GOST 859−2001, here and hereafter. — Note the manufacturer’s database.

4.2. Preparation for assay

4.2.1. Preparation of standard solutions

Solution a: a sample of cobalt metal by weight 0,100 g dissolved in 20 cmof a mixture of nitric and hydrochloric acids (in the ratio 1:3) when heated to remove oxides of nitrogen. Then evaporated to wet salts. Pour 10 cmof hydrochloric acid and evaporated to dryness. Treatment with hydrochloric acid is repeated 2 times.

The dry residue is dissolved in 30−50 cmof hot water, cooled, placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmof the solution contains 1 mg of cobalt.

Solution B: 5 cmsolution And placed in a volumetric flask with a capacity of 500 cmand was adjusted to the mark with water.

1 cmof a solution contains 0.01 mg of cobalt.

The solution, freshly prepared: 10 cmof solution B is placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmof the solution contains 0.001 mg of cobalt.

Solution G, freshly prepared: 10 cmsolution is placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmsolution G contains 0.0001 mg to

ebalta.

4.2.2. Construction of calibration curve

4.2.2.1. When the mass fraction of cobalt from 0,00002 to 0.0001%.

Two batches of copper cathode mass of 1,000 g (for each point of calibration curve) add 2,0; 3,0; 4,0; 5,0 and 10,0 cmstandard solution G, which corresponds to 0,0002; 0,0003; 0,0004; 0,0010 and 0,0005 mg of cobalt, and further all operations are carried out as specified in clause 4.3.1.

According to the obtained values of optical density and relative concentration of cobalt to build a calibration curve.

4.2.2.2. When the mass fraction of cobalt from 0.0001 to 0.005%.

Two batches of copper cathode mass of 1,000 g (for each point of calibration curve) was added to 1.0; 5.0 cmstandard solution and 1,0; 2,5; 5,0 cmstandard solution B, which corresponds to 0,001; 0,005; 0,010; 0,025; 0,050 mg of cobalt. Further all operations are carried out as specified in clause 4.3.1.

4.3 analysis

4.3.1. A sample of copper weighing 1,000 grams is placed in a glass (conical flask) with a capacity of 250 cm, flow 15 cmof nitric acid diluted 1:1, and heated to dissolve the attachment and removal of nitrogen oxides. The solution was boiled down on the stove with asbestos to a volume of 2 cmthree times and then treated with hydrochloric acid in portions of 10 cmfor the complete removal of oxides of nitrogen, evaporating twice to wet salts and the last time dry. To the dry residue add 100 cmof water and heated to dissolve the salts.

The solution was added 7−8 pellets of aluminum metal, the total mass of which is from 3.5 to 4.0 g, and heated at 80−90 °C for 2−3 h until complete separation of copper (solution should be clear with no blue tint).

After cementation of copper solution by decantation was transferred to a beaker with a capacity of 100 cm, carefully washed walls and copper precipitated with water, adding the washings to the main solution so that copper did not get into solution and removed asbestos to a volume of 20−30 cm.

After cooling, to the solution was added with stirring a mixture of 5 cmof a solution of citric acid and 10 cmof a solution of 1-nitroso-2-naphthol (mixture prepared before addition to each sample). The solution is neutralized by preformed potassium hydroxide to a pH of 4.0 to 4.5, heated to boiling, and add 0.3 cmof hydrogen peroxide. The glass is covered with a cover glass, the solution was boiled for 10 min and then cooled to room temperature.

The solution was transferred to a separatory funnel with a capacity of 100 cm, add 10 cmof toluene and extracted for 2 minutes the Extract is washed with 10 cmof hydrochloric acid solution 4 mol/DMfor 1 min, then 10 cmof potassium hydroxide solution 50 g/DMfor 1 min, and then twice 10 cmof potassium hydroxide solution 5 g/lwithin 1 min Extract is drained into a dry test tube and measure the optical density on the spectrophotometer at a wavelength of 410 nm in a cuvette with a layer thickness of 20 mm. Solution comparison of SL

with toluene.

4.3.2. The control experience

Copper, precipitated on aluminum, free of cobalt, dissolved in nitric acid, diluted 1:1. The solution is evaporated to a volume of 2−3 cmand then repeat all the operations as specified in clause 4.3.1.

4.4. Processing of the results

4.4.1. Mass fraction of cobalt () in percent is calculated by the formula

,

where is the mass of cobalt in the solution of the sample, µg;

 — the mass of cobalt in the solution in the reference experiment, µg;

 — weight of copper,

4.4.2. Allowable absolute differences of the results of two parallel measurements at a confidence level =0.95 is (the rate of convergence) and the results of the analysis of the same samples obtained in two laboratories and one reference laboratory, but under different conditions (a measure of reproducibility) shall not exceed the values given in table.4.

Table 4

4.4.3. Control of the correctness of the results of the analysis carried out in accordance with PP.2.4.3, 2.4.4.

5. METHODS FOR DETERMINATION OF ARSENIC

5.1. Photometric method

The method is based on fotomaterialy painted arsenic-molybdenum complex. Arsenic pre-allocate ammonia by precipitation with iron hydroxide and subsequent extraction of arsenic with carbon tetrachloride.

5.1.1. Equipment, reagents, solutions

Spectrophotometer or photoelectrocolorimeter.

The glass is high or low capacity of 400, 250 cmaccording to GOST 25336.

Funnel separating VD-1−250 KHS with a capacity of 250 and 1000 cmaccording to GOST 25336.

Flasks conical KN-1−250 (400)-14/23 the TC or TCS with GOST 25336.

Volumetric flasks with a capacity of 50, 100, 200 cmaccording to GOST 1770.

Pipette 2−2-10, 4−2-2, 7−2-5 according to GOST 20292.

Flask Kjeldahl GOST 25336.

Buchner funnel according to GOST 9147.

Nitric acid of high purity according to GOST 11125 or GOST 4461, distilled, diluted 1:1.

Sulfuric acid according to GOST 4204, diluted 1:3 and 1:10, solutions with molar concentration 0.5 and 3 mol/DM.

Hydrochloric acid of high purity according to GOST 14261, density of 1.19 g/cmand diluted 1:1, solution with molar concentration of 9 mol/DM. The acid is purified from arsenic: a portion of iodide of potassium with a mass of 10 g is dissolved in 500 cmof hydrochloric acid and transfer the solution into a separating funnel with a capacity of 1000 cm, add 25 cmof carbon tetrachloride, shaken for 2 min. the Organic layer discarded after settling. To the solution in separating funnel add 25 cmof carbon tetrachloride and shake for 2 min. the Organic layer discarded. Cleaning acid is carried out before use.

Potassium iodide according to GOST 4232.

Carbon tetrachloride according to GOST 20288, distilled.

The technical rectified ethyl alcohol according to GOST 18300.

Ammonia water according to GOST 3760, distilled.

Ammonium molybdate according to GOST 3765, a solution of 10 g/lin sulfuric acid 3 mol/DM. The reagent before use twice recrystallized from alcoholic solution: a sample of salt mass of 70 g was dissolved in 400 cmof hot water and twice filtered through a dense filter. To the filtrate is added 250 cmof ethyl alcohol and allowed to stand for 1 h at room temperature, after which the crystals are sucked off on a Buchner funnel. Received ammonium molybdate was dissolved and recrystallized again. The crystals are sucked off again on a Buechner funnel, washed 2−3 times with ethanol in batches of 20−30 cm, after which the crystals are dried in air.

Hydrazine sulfate according to GOST 5841, a solution of 1.5 g/DM.

Hydrazine molybdate solution: to 50 cmof a solution of ammonium molybdate add 5 cmof a solution of hydrazine and dilute with water to volume of 100 cm; prepare before use.

Alum salesonline, a solution of 100 g/DM: a sample of salt weighing 10 g was placed in a beaker with a capacity of 250 cm, 5 cm pour thenitric acid and 70 cmof water. Heated to dissolve the sample, cooled and filtered the solution through a filter of medium density. The filter is discarded and the filtrate diluted with water to a volume of 100 cm.

Sodium carbonate 10-water according to GOST 84, a saturated solution.

Sodium hydroxide according to GOST 4328, solution with molar concentration of 1 mole/DM.

Potassium permanganate according to GOST 20490, solution with molar concentration of 0.06 mol/DM.

Ammonium chloride according to GOST 3773, solution 20 g/DM.

Titanium trichloride according to GOST 311, a solution of 400 g/DM.

Titanium.

The titanium sulfate solution: 2.0 g of titanium dissolved in 40 cmof sulphuric acid, diluted 1:3 in the Kjeldahl flask with reflux condenser. Once dissolved, add sulphuric acid, diluted 1:10, to a volume of 1000 cm. The solution is stored in a carbon dioxide atmosphere.

Anhydride mouse

jakobity according to GOST 1973.

5.1.2. Preparation for assay

5.1.2.1. Preparation of standard solutions

Solution a: a portion of the arsenious anhydride weight 0,0266 g is placed in a volumetric flask with a capacity of 200 cm, pour 2 cmof sodium hydroxide solution and 50 cmof water, stirred to dissolve the sample. After that add 3 cmof sulphuric acid molar concentration of 0.5 mol/DMand adjusted to the mark with water.

1 cmof solution A contains 0.1 mg of arsenic.

Solution B: take 10 cmof solution A and placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmof a solution contains 0.01 mg of mouse

ka.

5.1.2.2. Construction of calibration curve

In a volumetric flask with a capacity of 50 cmplaced 0,0; 0,5; 1,0; 1,5; 2,0; 2,5 and 3.0 cmstandard solution B, which corresponds to 0,00; 0,005; 0,010; 0,015; 0,020; 0,025 and 0.030 mg of arsenic. In each flask pour 40 cmof water and add all the reagents in the same order as specified in clause 5.1.3. Solution comparison is the solution not containing arsenic.

According to the obtained values of optical densities and the corresponding weight fractions of arsenic build a calibration curve in rectangular coordinates.

5.1.3 analysis

A sample of copper with a mass given in table.5, is placed in a beaker or conical flask with a capacity of 500 cmand pour nitric acid, diluted 1:1, in the amount indicated in the table.5. Heated to dissolve the attachment and removal of nitrogen oxides.

Table 5

To the obtained solution poured 100 cmof water, add 1 cmgentoomaniac alum solution, heated to 60−70 °C and precipitated arsenic and iron hydroxide with sodium carbonate solution. The solution with the sediment bring to the boil and leave at a temperature of 40−50 °C for 20 min to coagulate the precipitate.

The precipitate was filtered on a medium density filter and washed 3−4 times with a solution of ammonium chloride. The precipitate is then dissolved on the filter with 25 cmof hydrochloric acid diluted 1:1, the filter is washed 2−3 times with hot water. To the filtrate flow of 100 cmof water, heated to 60−70 °C and re-precipitated arsenic and iron hydroxide. The precipitate was filtered through the same filter and washed 3−4 times with hot water.

Dissolve the precipitate on the filter with 25 cmof hydrochloric acid diluted 1:1, collecting the filtrate in a beaker, in which was conducted the deposition. The filter was washed 3−4 times with hot water and discarded.

The filtrate restore iron and arsenic, adding drop by drop a solution of sulphate or chloride of titanium to a bleaching solution and then another 1−2 drops.

The solution was placed in a separating funnel with a capacity of 250 cm, pour three times the volume of purified hydrochloric acid, add 30 cmof carbon tetrachloride and extracted within 2 min. After settling, the organic layer drained into another separating funnel, and add more in the first 15 cmof carbon tetrachloride and repeat the extraction.

The combined organic extracts are washed with 20 cmof hydrochloric acid with molar concentration of 9 mol/DMfor 20 s, then to the organic layer poured 15 cmof water and carry out the Stripping of arsenic for 2 min. Separated the organic layer and repeat the Stripping under the same conditions.

Water layers merge into a measuring flask with a capacity of 50 cm, is added dropwise a solution of potassium permanganate until a stable pink colour, which is then destroyed, priliva dropwise a solution of hydrazine. In a flask was added 4 cmof freshly prepared hydrazine-molibdate solution and place the flask in a boiling water bath for 15 min.

The solution was then cooled and adjusted to the mark with water. Measure the optical density at a wavelength of 610 nm in a cuvette with an optimum thickness of the layer. Solution comparison is water.

The mass of arsenic found by calibration g

Rafik.

5.1.4. Processing of the results

5.1.4.1. Mass fraction of arsenic () in percent is calculated by the formula

,

where is the mass of arsenic in the analyzed solution samples, was found in the calibration graphics mg;

 — the mass of arsenic in solution in the reference experiment, mg;

 — weight of copper,

5.1.4.2. Allowable absolute discrepancies in the results of two parallel determinations for sample analysis at a confidence level =0.95 is (the rate of convergence) and the results of the analysis of the same sample obtained in different laboratories, and in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values given in table.6.

Table 6

5.2. Colorimetric method

The method is based on visual comparison of color intensity of the arsenic compounds of hydrogen and methyl mercury after recovery of arsenic and metallic zinc.

5.2.1. Materials, reagents, solutions

Paper Bremerton: a suspension of bromide of mercury with a mass of 2.5 grams is dissolved in 50 cmof ethanol, the solution was immersed for 1 h obestochennye the filters, then dried obtained Bremerton paper on the glass and stored in a flask made of dark glass. The paper is suitable for 30 days. To keep the colour of the paper it is treated: twice immersed for 1 min in ethanol, then for 1 min in diethyl ether and air dried. Then a circle of paper are immersed for a few seconds in hot paraffin (~80 °C). Treated with paraffin paper stored in a dark place.

Medical absorbent cotton wool GOST 5556 impregnated with a solution of acetate of lead. Pre-degreased wool processing diethyl ether for 30 min. Stored in a flask made of dark glass with a glass stopper.

Nitric acid according to GOST 4461 and diluted 1:2, 1:1.

Hydrochloric acid according to GOST 3118.

Ammonia water according to GOST 3760 and diluted 1:99.

Salt of protoxide of iron and ammonium double sulfate (salt Mora) according to GOST 4208, or alum salesonline, a solution of 20 g/DM.

Tin dichloride, the solution 200 g/lin hydrochloric acid (1:1).

The diethyl ether medical.

Acetic acid according to GOST 61, 30% solution.

Lead acetate according to GOST 1027, a solution of 40 g/DM: to a suspension of salt add appropriate amount of water and dropwise a solution of acetic acid to the bleaching solution.

Zinc granulated GOST 3640*.
______________
* On the territory of the Russian Federation GOST 3640−94. — Note the manufacturer’s database.

Sodium hydroxide according to GOST 4328, solution 100 g/DM.

The technical rectified ethyl alcohol according to GOST 18300.

Arsenious anhydride according to GOST 1973.

The bromide of mercury.

5.2.2. Preparation for assay

5.2.2.1. Preparation of standard solutions

Solution a: 0,1320 g of arsenious anhydride were placed in a glass with a capacity of 100 cm, flow 10 cmof sodium hydroxide solution, stirred to dissolve the sample. Transfer the solution into a measuring flask with volume capacity of 1000 cmand was adjusted to the mark with water.

1 cmof solution A contains 0.1 mg of arsenic.

Solution B: aliquot part 10 cmof the solution And placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmof a solution contains 0.01 mg of arsenic.

Solution: aliquot part 10 cmof solution B is placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmof the solution contains 0.001 mg mouse

Yak.

5.2.2.2. Cooking scale

In a device for distillation (damn.) put 1, 2, 3, 4, 5 and 6 cmstandard solution, add 7 cmof hydrochloric acid and injected 2 cmof salt solution Mora or gentoomaniac alum, 1 cmof a solution of tin dichloride and 5 g of zinc. Quickly close the tube with a nozzle and allowed to stand in a dark place 50−60 min. Bremerton paper scale stored in a dark place.

1 — glass tube with a diameter of 14 mm filled with cotton or paper impregnated with a solution of acetate of lead, and inserted into the tube; 2 — glass tube with a diameter of 2−3 mm, upper end of which is placed a circle Bremerton paper with a diameter of 10 mm, then a circle of filter paper with a diameter of 15−20 mm and tightly pressed against the rubber ring; 3 — screw the two clips on top of each other and made of an organic glass

5.2.3. Analysis

A sample of copper with a mass of 3.00 g is placed in a conical flask with a capacity of 250−300 cm, dissolved in 50 cmof nitric acid, diluted 1:1, when heated to remove oxides of nitrogen. Then pour 150 cmof water and boil it.

Introduced 3 cmof salt solution Mora (or gentoomaniac alum) and the hydroxides precipitated with ammonia. Provide sediment to koagulirovat and filtered through a medium density filter, washed 5−6 times with ammonia diluted 1:99. The precipitate is then washed into a flask in which the precipitation was carried out, and dissolved in hydrochloric acid, the filter was washed 2−3 times with hot water. Repeat the precipitation of the hydroxides with ammonia. Filtered through the same filter and washed with hot ammonia diluted 1:99 until the filter traces of copper. Unfold the filter and dissolve the precipitate in 10 cmof hydrochloric acid diluted 1:1, washed 5−6 times with hot water, placing the filtrate in a flask in which to carry out the deposition. Dilute with water to volume of 50 cm, add 5 g of zinc and quickly cover the tube with a nozzle, which is placed cotton wool impregnated with lead acetate; leave in the dark for 50−60 min.

The mass of arsenic found at a scale, which is prepared once in two weeks and always when changing reagents, simultaneously with the analysis.

5.2.4. Processing of the results

5.2.4.1. Mass fraction of arsenic () in percent is calculated by the formula

,

where is the mass of arsenic, was found on a scale of standard solutions mg;

 — weight of copper,

5.2.4.2. Discrepancies in the results of two parallel measurements and the two tests should not exceed the values given in table.6.

5.2.4.3. Control of the correctness of the results of the analysis carried out in accordance with PP.2.4.3, 2.4.4.

6. PHOTOMETRIC METHOD FOR DETERMINATION OF SILICON

The method is based on measuring the optical density at a wavelength of 750−800 nm blue colored complex of silicon with the ammonium molybdate.

6.1. Equipment, reagents, solutions

Spectrophotometer or photoelectrocolorimeter of any type.

Installation for electrolysis.

Laboratory scales analytical any type of the 2nd accuracy class with the error of weighing according to GOST 24104.

The electrodes are platinum mesh according to GOST 6563.

a pH meter.

Bowls and crucibles of platinum according to GOST 6563.

Volumetric flasks with a capacity of 50, 100, 250 cmaccording to GOST 20292.

Pipette 2−1-2 GOST 1770.

Sulfuric acid according to GOST 4204, diluted 1:1.

Nitric acid of high purity according to GOST 11125, diluted 2:1, 1:1, 1:2.

Ammonia water according to GOST 3760.

Citric acid according to GOST 3652, a solution of 500 g/DM.

Ammonium molybdate according to GOST 3765, twice recrystallized; solution 100 g/l, containing 25 cmof ammonia in 500 cmof a solution.

Tin dichloride, a solution of 10 g/DMhydrochloric acid diluted 1:1.

Sodium hydroxide according to GOST 4328.

Silicon dioxide according to GOST 9428, calcined at 1000 °C to constant weight.

Indicator paper type «Rfat» that contains the pH value from 1.0 to 1.4.

6.2. Preparation for assay

6.2.1. Preparation of standard solutions

Solution a: a sample of silicon dioxide mass 0,0856 g is placed in a platinum crucible and fused with 1.0 g of sodium carbonate at a temperature of 900−1000 °C. the Alloy is leached with hot water, cooled, placed in a volumetric flask with a capacity of 1000 cmand was adjusted to the mark with water.

1 cmof the solution contains 0.04 mg of silicon.

Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmof a solution contains 0.004 mg of silicon: a solution is prepared before use, store in a container made of polyethylene.

6.2.2. Construction of calibration curve

In a volumetric flask with a capacity of 50 cmis placed 0,0; 0,5; 1,0; 2,0, 5,0 and 10,0 cmstandard solution B, which corresponds to 0,0; 0,002; 0,004; 0,008; and 0,020 0,040 mg of silicon. In each flask poured to a volume of 15−20 cmof water and neutralized with ammonia or nitric acid to a pH of 1.2−1.4 (by indicator paper or pH-meter). Then pour 2 cmof a solution of citric acid and allow the solutions to stand for another 5 min. After that, the flasks add 5 cmof ammonium molybdate solution, 0.2 cmof a solution of dichloride of tin and adjusted to the mark with water.

Measure the optical density of the solution on the spectrophotometer or photoelectrocolorimeter at a wavelength of 750−800 nm in a cuvette with an optimum thickness of the layer. Solution comparison is the solution of the reference experiment. According to the obtained values build a calibration curve in rectangular coordinates.

6.3. Analysis

A sample of copper with a mass of 2.00 g (when the mass fraction of silicon, 0.002%) or 0.50 g (with mass fraction of silicon of more than 0,002%) were placed in a glass with a capacity of 250 cm, flow 20 cmnitrogen 5 cmof sulphuric 1:1 acid, cover the beaker glass and leave you without heating until the termination of allocation of oxides of nitrogen. Remove the glass, wash it with water over the beaker and the solution is heated to dissolve the sample. Then pour the 150−180 cmof water, heat the solution to a temperature of 40 °C, immersed in a solution of a platinum mesh electrodes and the electrolysis is carried out for 2−2. 5 h at a current density of 2−3 A/DMa voltage of 2.2−2.5 with stirring.

When the solution is colorless, the electrodes are removed, washed with water, and the electrolyte is evaporated to a volume of 10−15 cm. Cool, add water to a volume of 20 cmand neutralized with ammonia or nitric acid, diluted 2:1, to pH values of 1.2−1.4 (by indicator paper, then check the pH-meter). Pour 2 cmof citric acid and allow to stand for 5 min. the Solution was transferred to volumetric flask with a capacity of 50 cm, pour 5 cmof ammonium molybdate solution, 0.2 cmof a solution of dichloride of tin and adjusted to the mark with water.

Measure the optical density of the solution on the spectrophotometer or photoelectrocolorimeter at a wavelength of 750−800 nm in a cuvette with an optimum thickness of the layer. Solution comparison is the solution of the reference experiment.

The mass of silicon is determined by the calibration gra

fico.

6.4. Processing of the results

6.4.1. Mass fraction of silicon () in percent is calculated by the formula

,

where is the mass of silicon in the solution of the sample, was found in the calibration graphics mg;

 — weight of copper,

6.4.2. Allowable absolute discrepancies in the results of two parallel determinations for sample analysis at a confidence level =0.95 is (the rate of convergence) and the results of the analysis of the same samples obtained in two laboratories and one reference laboratory, but under different conditions (a measure of reproducibility) shall not exceed the values given in table.7.

Table 7

6.4.3. Control of the correctness of the results of the analysis carried out in accordance with PP.2.4.3, 2.4.4.

7. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF NICKEL

The method is based on measuring the optical density of the colored complex compounds of Nickel with dimethylglyoxime at a wavelength ranges from 520 to 540 nm. Copper is removed by a preliminary electrolysis.

7.1. Equipment, reagents, solutions

Spectrophotometer or photoelectrocolorimeter of any type.

Installation for electrolysis.

The electrodes are platinum mesh according to GOST 6563.

a pH meter.

Volumetric flasks 2−50−2, 2−100−2, 2−250−2, 2−500−2, 2−1000−2 according GOST 1770.

Pipette 7−2-5, 2−2-25 according to GOST 20292.

Nitric acid according to GOST 4461, diluted 2:1.

Sulfuric acid according to GOST 4204.

Hydrochloric acid according to GOST 3118, a solution of 0.5 mol/DM.

The mixture of acids to dissolve: mix 500 cmof sulfuric acid in 1250 cmof water, after cooling add 350 cmof nitric acid and stirred.

Ammonia water according to GOST 3760 diluted 1:1, 2:98.

Sodium hydroxide according to GOST 4328, a solution of 40 mol/DM.

Dimethylglyoxime according to GOST 5828, a solution of 10 g/lin ethanol and a solution of sodium hydroxide.

The technical rectified ethyl alcohol according to GOST 18300.

Ammonium neccersarily according to GOST 20478, a solution of 100 g/DM.

Chloroform according to GOST 20015.

Hydroxylamine hydrochloride according to GOST 5456, solution 100 g/DM.

Sodium citrate according to GOST treasuremania 22280, solution 100 g/DM.

Triethanolamine solution 100 g/DM.

Potassium-sodium vinocity according to GOST 5845, solution 100 g/DM.

Ammonium chloride according to GOST 3773, a solution of 60 g/DM.

Disodium salt of ethylenediaminetetraacetic acid, 2-water (Trilon B) according to GOST 10652, a solution of 0.05 mol/DM.

Phenolphthalein a solution of 0.10 g/lin ethanol.

Hydrogen peroxide according to GOST 10929.

The primary Nickel GOST 849*.
______________
* On the territory of the Russian Federation GOST 849−97 (01.07.2009 standards 849−2008). — Note the manufacturer’s database.

Nickel sulfate according to GOST 4465.

7.2. Preparation for assay

7.2.1. Preparation of standard solutions

Solution a: a sample of metallic Nickel weighing 0,100 g dissolved in 5−10 cmof hydrochloric acid with the addition of 2−3 cmof hydrogen peroxide. After dissolution, the sample solution was cooled, poured 5−7 cmof sulphuric acid diluted 1:1, and the solution was evaporated until the appearance of dense white fumes of sulfuric acid. Cooled, poured 100−120 cmof water, heated to dissolve salts and cooled again. Put the solution into a measuring flask with volume capacity of 1000 cmand was adjusted to the mark with water.

1 cmof solution A contains 0.1 mg of Nickel.

The same solution can be prepared from Nickel sulfate: hitch salt weight 0,4784 g is placed in a measuring flask with volume capacity of 1000 cm, pour 100−200 cmwater, 1 cmof sulfuric acid, stirred to dissolve the sample and adjusted to the mark with water.

Solution B: aliquot part 10 cmof the solution And placed in a volumetric flask with a capacity of 100 cm, pour 1 cmof sulfuric acid diluted 1:1, and adjusted to the mark with water.

1 cmof a solution contains 0.01 mg of Nickel.

Solution: aliquot part 10 cmof solution B is placed in a volumetric flask with a capacity of 50.0 cm, add 0.5 cmof sulphuric acid diluted 1:1, and adjusted to the mark with water.

1 cmof the solution contains 0,002

mg Nickel.

7.2.2. Construction of calibration curve

In a volumetric flask with a capacity of 50 cmis placed 0,0; 1,0; 2,0; 3,0; 4,0 and 6,0 cmstandard solution, which corresponds to 0,0; 0,002; 0,004; 0,006; 0,008 and 0.012 mg of Nickel. To each flask add water to volume of 10 cm, then 2 cmof a solution of potassium-sodium Vinokurova 5 cmof sodium hydroxide solution, 5 cmsolution dimethylglyoxime in a solution of sodium hydroxide and after addition of each reagent mix. After 5−7 min. pour 5 cmof the solution Trilon B and 5 cmof a solution of ammonium chloride and was adjusted to the mark with water.

Measure optical density of solution in 7 to 10 min in the spectrophotometer or photoelectrocolorimeter at a wavelength ranges from 520 to 540 nm in a cuvette with an optimum thickness of the layer. Solution comparison is water.

According to the obtained values of optical density and corresponding mass concentrations of Nickel in standard solutions calibration curve built in a rectangular coordinate

H.

7.3. Analysis

A sample of copper with a mass of 2,000 g were placed in a glass with a capacity of 400 cm, 20−25 cm, pour themixture of acids to dissolve and heated to dissolve the attachment and removal of nitrogen oxides. Cooled, poured 150−160 cmof water, were placed in a glass platinum mesh electrodes and the electrolysis is carried out at a current of 2−2. 5 A and a voltage of 2−2,5 V. At the end of the electrolysis, the electrodes are removed from solution and washed with ethanol (10 cmof alcohol per one definition), then with water.

The electrolyte is evaporated under heating to a volume of 50−70 cmand after cooling is placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

Depending on the mass fraction of Nickel in copper are selected aliquot part 5, 10, 20 cm. Place it in a separatory funnel with a capacity of 100 cm, is diluted with water to a volume of 50 cmand pour 1 cmof a solution of triethanolamine, 5 cmof a solution of citrate of sodium, 2 cmof a solution of hydrochloric acid hydroxylamine, and stirred solution. Then add 2−3 drops of solution of phenolphthalein and neutralized with ammonia until the appearance of pink color and then another 2−3 drops of ammonia.

Poured in separating funnel 10 cmdimethylglyoxime alcohol solution, 2−3 min 10 cmof chloroform and extracted for 1 min. the Organic layer drained into another separatory funnel with a capacity of 50 cm, and the water layer poured another 5 cmof chloroform and repeat the extraction. Extract attached to the first portion, and the aqueous layer discarded.

To the combined extracts add 15 cmof ammonia, diluted 1:49, and extracted for 1 min. the Aqueous layer is discarded and to the organic flow of 15 cmof ammonia solution and the extraction repeated. The aqueous layer is again discarded.

For the extraction of Nickel from chloroform extract in the separatory funnel pour 15 cmof hydrochloric acid with a molar concentration of 0.5 mol/DMand vigorously shaken for 1 min. the Organic layer drained into another separatory funnel with a capacity of 50 cmand repeat the re-extraction with 15 cmof hydrochloric acid with a molar concentration of 0.5 mol/DM. The organic layer is discarded and the hydrochloric acid poured into a glass with a capacity of 100 cmand evaporated to dry salts.

To the dry residue pour 1−2 cmof the mixture of nitric and hydrochloric acids (1:3) and again evaporated to dry salts. Then add 1 cmof hydrochloric acid and evaporated to dryness. The dry residue moistened with 0.5−1 cmof hydrochloric acid, with a molar concentration of 0.5 mol/DM, add 8−10 cmof water and placed the solution in a volumetric flask with a capacity of 50 cm.

To the solution in the flask is poured successively, mixing after each addition of reagent, 2 cmof a solution of potassium-sodium Vinokurova, 5 cmsolution naternicola ammonium and continue the analysis as described in section 7.2.2.

Mass of Nickel and determine the p

on the calibration schedule.

7.4. Processing of the results

7.4.1. Mass fraction of Nickel () in percent is calculated by the formula

,

where is the mass of Nickel in solution of the sample, was found in the calibration graphics mg;

 — the mass of Nickel in solution in the reference experiment, mg;

 — weight of copper,

7.4.2. Allowable absolute discrepancies in the results of two parallel determinations for sample analysis at a confidence level =0.95 is (the index of convergence) the results of the analysis of the same samples obtained in two different laboratories, one laboratory, but under different conditions (a measure of reproducibility) shall not exceed the values given in table.8.

Table 8

7.4.3. Control of the correctness of the results of the analysis carried out in accordance with PP.2.4.3, 2.4.4.

8. SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF SELENIUM

The method is based on measuring the optical density of the complex compounds of selenium -phenylendiamine is extracted with benzene or toluene. Preventing the effect of copper is eliminated by addition of excess of reagent, iron — phosphoric acid, bismuth — Trilon B.

8.1. Equipment, reagents, solutions

A spectrophotometer of any type.

Beakers, conical flasks with a capacity of 250 cmaccording to GOST 25336.

Volumetric flasks 2−100−2, 2−500−2 according GOST 1770.

Pipette 7−2-5, 7−2-10, 2−2-20 according to GOST 20292.

Burette 1−2-25−0,05 to GOST 20292.

Nitric acid according to GOST 4461 and diluted 1:1.

Sulfuric acid according to GOST 4204, diluted 1:1 and 2:98.

Orthophosphoric acid according to GOST 6552.

Hydrochloric acid according to GOST 3118.

Formic acid according to GOST 5848.

Salt is the disodium Ethylenediamine-, , , -tetraoxane acid 2-water (Trilon B) according to GOST 10652, solution 0,1 mol/DM.

Benzene according to GOST 5955.

Toluene according to GOST 5789.

-phenylendiamin hydrochloric acid, 1% aqueous solution (use a freshly prepared solution). Allowed the use of reagent qualification below h.d. a.

Selenium according to normative-technical documentation.

Universal indicator paper

.

8.2. Preparation for assay

8.2.1. Preparation of standard solutions

Solution a: a sample of selenium with a mass of 0.050 g were placed in a glass with a capacity of 100 cm, poured 7−10 drops of nitric acid, dissolved selenium when heated on a water bath, pour 10 cmof hydrochloric acid. To the solution add 15−20 cmof water, cooled and transferred to a volumetric flask with a capacity of 500 cm, pour 15−20 cmof hydrochloric acid and was adjusted to the mark with water.

1 cmof solution A contains 0.1 mg of selenium.

Solution B: 5 cmsolution with a pipette And transferred to a volumetric flask with a capacity of 500 cm, poured 5cmof hydrochloric acid and was adjusted to the mark with water.

1 cmof the solution contains 0.001 mg of the villages

ena.

8.2.2. Construction of calibration curve

In a conical flask with a capacity of 100 cmplaced 0,0; 0,5; 1,0; 2,0; 3,0; 5,0; 7,0; 10,0 and 15.0 cmstandard solution B, which corresponds to 0,0; 0,0005; 0,0010; 0,0020; 0,0030; 0,0050; 0,0070; 0,0100 and 0,0150 mg of selenium. The solutions were diluted with water to a volume of 30−35 cm, pour 1 cmof formic acid. 5 mmphosphoric acid, 0.5 cmof the solution Trilon B, and then drop by drop ammonia to a pH of~1 (universal indicator paper). After that add 3 cmof a solution of phenylendiamine and leave it for 20−25 min.

The resulting solution was placed in a separating funnel with a capacity of 100 cm, poured from a burette 5 cmof benzene or toluene and extracted for 2 minutes the Extract is drained to a dry test tube and measure its optical density on the spectrophotometer at a wavelength of 335 nm in a cuvette with a layer thickness of 10 mm.

Solution comparison is the benzene (toluene).

According to the obtained values of optical density and corresponding selenium concentrations to build calibration curve in rectangular coordinates

max.

8.3. Analysis

Two sample of copper weighing 1,000−2,000 g (table.9) is placed in glasses with a capacity of 250 cm. In one glass an additive injected standard solution of selenium, the amount of which is chosen so that the analytical signal component is increased 2−3 times compared to the analytical signal in the absence of additives.

Table 9

Into glasses pour 20−25 cmof nitric acid, diluted 1:1, and leave without heat for 5−10 min. Then solution is heated and evaporated to a volume of 4−5 cm. Cooled, poured 10 or 20 cmof sulphuric acid diluted 1:1, and heated to release vapors of sulfuric acid. The solution was cooled, poured 5−10 cmof water and again evaporated until the appearance of fumes of the acid. After cooling, poured 20 or 40 cmof water, cover the beaker glass and heated to boiling. The solution was then cooled and, depending on the sample taken it was placed in the conical or volumetric flask with a capacity of 100 cm. Solution in a volumetric flask diluted to the mark with water and mix.

The entire solution or aliquot part of the solution (table.9) with a volume of 10−20 cmis transferred to a conical flask with a capacity of 100 cm, is diluted with water so that the final volume did not exceed 30−35 cm, add 1 cmof formic acid. 5 mmphosphoric acid, 0.5 cmof the solution Trilon B, then drop by drop ammonia to a pH~1; 3 cm-phenylendiamine and leave for 20−25 min Then the solution was poured into a separatory funnel, poured from a burette 5 cmof benzene or toluene and extracted for 2 minutes the Extract is drained to a dry test tube and measure the optical density on the spectrophotometer at a wavelength of 335 nm in a cuvette with a layer thickness of 10 mm Solution comparison is benzene (toluene).

Selena weight set calibration

graphics.

8.4. Processing of the results

8.4.1. Mass fraction of selenium () in percent is calculated by the formula

,

where is the mass of selenium was found in the calibration graphics mg;

 — capacity volumetric flasks, cm;

 — volume aliquote part of the solution, cm;

 — weight of copper,

8.4.2. Allowable absolute differences of the results of two parallel measurements at a confidence level =0.95 is (the rate of convergence) and the results of the analysis of the same samples obtained in two laboratories and one reference laboratory, but under different conditions (a measure of reproducibility) shall not exceed the values given in table.10.

Table 10

8.4.3. Control of the correctness of the results of the analysis carried out in accordance with the PP.2.4.3, 2.4.4.

9. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF ANTIMONY

The method is based on measuring the optical density at a wavelength of 590 nm of the colored chloride complex of antimony (V) with brilliant green after separation by coprecipitation of antimony with metalbands acid, oxidation of antimony (III) atomistically sodium and extraction of the complex of toluene (benzene).

9.1. Equipment, reagents, solutions

Spectrophotometer or photoelectrocolorimeter of any type.

Footwear of any type of the 2nd accuracy class with the error of weighing according to GOST 24104.

Volumetric flasks 2−100−2, 2−250−2, 2−1000−2 according GOST 1770.

Pipette 7−2-5, 7−2-10, 2−2-20 according GOST 1770.

Funnel separating VD-3−100 TC GOST 25336.

A dephlegmator according to GOST 25336.

Nitric acid according to GOST 4461 and diluted 3:97.

Sulfuric acid according to GOST 4204, and diluted 1:1, 1:10.

Hydrochloric acid according to GOST 3118, diluted 7:3, 3:1, 1:10 and a solution of 2 mol/DM.

Ammonium nitrate according to GOST 22867, a solution of 150 g/DM.

Brilliant green, water-alcohol solution of 5 g/DM: 0.5 g of reagent was dissolved in 100 cmof a mixture of alcohol and water in the ratio 1:3.

The iron powder according to GOST 9849, a solution of 15 g/lin hydrochloric acid, diluted 1:10.

Urea according to GOST 6691, a saturated solution of 50 g of urea is dissolved by heating in 50 cmof water, the solution was then filtered.

Sodium atomistically according to GOST 4197, solution 100 g/DM.

Tin dichloride, solution 100 g/lin hydrochloric acid, diluted 1:1.

Tin GOST 860.

Toluene according to GOST 5789 (distilled) or benzene according to GOST 5955.

The technical rectified ethyl alcohol according to GOST 18300.

Trioxide of antimony.

Antimony GOST 108

9.

9.2. Preparation for assay

9.2.1. Standard solutions of antimony

Solution a: a portion of the antimony by weight 0,100 g was placed in a conical flask with a capacity of 250 cm, flow 20 cmof sulfuric acid and heated to dissolve sample. After cooling, placed in a volumetric flask with a capacity of 1000 cm, is diluted to the mark with sulfuric acid diluted 1:10, and stirred. In the preparation of the solution And antimony trioxide hitch weight 0,1200 g is placed in a conical flask with a capacity of 1000 cm, equipped with a reflux condenser. Pour 200cmof hydrochloric acid diluted 7:3, and heated to dissolve sample. After cooling, the solution is evaporated to a volume of 5−10 cm, placed in a volumetric flask with a capacity of 1000 cmand was adjusted to the mark with sulfuric acid diluted 1:10.

1 cmof solution A contains 0.1 mg of antimony.

Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with sulfuric acid diluted 1:10. Use freshly prepared solution.

1 cmof a solution contains 0.01 mg of antimony.

Solution In 20 cmof solution B is placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with sulfuric acid diluted 1:10. Use freshly prepared solution.

1 cmof the solution contains 0.002 mg

antimony.

9.2.2. Construction of calibration curve

In nine of the ten cups with a capacity of 50 cmis placed 1,0; 2,0; 3,0; 4,0 and 5,0 cmstandard solution and 2.0 and 3.0 cmstandard solution B, which corresponds to 0,002; 0,004; 0,006; 0,008; 0,010; 0,020; 0,030 mg of antimony. The solutions are evaporated to wet salts, cool, add 10 cmof hydrochloric acid, diluted 3:1, heated to dissolve the salts, is cooled, add three drops of solution of ferric chloride, a solution of tin dichloride to the reduction of iron, 1 cmof a solution of sodium attestatio and leave for 5 mins Wash the side of the Cup with water and pour 1 cmof the urea solution. Transfer the solutions into a separating funnel with a capacity of 100 cm, adjusted with water to a volume of 75 cm(the label on the funnel), add 1−2 cmof the solution of brilliant green, 10 cmof toluene or benzene and extracted for 1 min. Toluene (benzene) layer was separated and after 15−20 min, measure the optical density of the extract on a spectrophotometer or photoelectrocolorimeter at a wavelength of 590 nm in a cuvette with a layer thickness of 10 mm Solution comparison serves as toluene (benzene).

According to the obtained values of optical density and corresponding mass of antimony standard solutions to build the calibration graph in rectangular coordinates

max.

9.3. Analysis

A sample of copper with a mass of 2,000 g were placed in a glass (or conical flask) with a capacity of 250 cm, add 0.01−0.02 g of tin, poured 20−25 cmof nitric acid, cover the beaker (flask) glass or a lid and heated to dissolve sample. Glass (cover) is removed, washed with water on the glass (bulb) and the solution is evaporated to a volume of 5−7 cm.

Then pour 100−120 cmof hot water, 20−25 cmammonium nitrate solution, add a little filtrowanie mass and boiled for 15−20 min and Leave the solution to precipitate in a warm place plate on a 2−2,5 hours.

After that filter the solution through a filter into the cone which is enclosed a little filtrowanie mass. The flask and filter washed 10−15 times with hot nitric acid, diluted 3:97.

The filter with precipitate was placed in a beaker or flask in which the precipitation was carried out, poured 20 cmof nitrogen and 10 cmof sulphuric acid, covered with a cover glass (or cover) and heated to remove oxides of nitrogen. Remove the glass, wash it with water over the glass (bulb) and the solution evaporated until the appearance of dense sulphuric acid fumes. If the solution darkens, then add ammonium nitrate to the bleaching solution.

Cooled, put the solution in a volumetric flask with a capacity of 50 cmand was adjusted to the mark with sulfuric acid diluted 1:10.

Select aliquot part of 25 cmand placed it in a glass with a capacity of 50 cm. Is evaporated when heated to wet salts, add 10 cmof hydrochloric acid, diluted 3:1, and heated to dissolve the salts. Then continue the analysis as described in section 9.2.2.

Mass of antimony is determined by calibration gra

fico.

9.4. Processing of the results

9.4.1. Mass fraction of antimony () in percent is calculated by the formula

,

where is the mass of antimony, was found in the calibration graphics mg;

 — capacity volumetric flasks, cm;

 — volume aliquote part of the solution, cm;

 — weight of copper,

9.4.2. Allowable absolute discrepancies in the results of two parallel determinations for sample analysis at a confidence level =0.95 is (the rate of convergence) and the results of the analysis of the same samples obtained in two laboratories and one reference laboratory, but under different conditions (a measure of reproducibility) shall not exceed the values given in table.11.

Table 11

9.4.3. Control the correctness of the results of the analysis carried out in accordance with the PP.2.4.3, 2.4.4.

10. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF PHOSPHORUS

The method is based on measuring the optical density at a wavelength of 620−630 nm or 720 colored complex compounds molybdophosphoric of heteroalicyclic after selective extraction with a mixture of butanol with chloroform.

10.1. Equipment, reagents, solutions

Spectrophotometer or photoelectrocolorimeter of any type.

The glasses are In 1−100 (150) or N-1−100 (150) TCS according to GOST 25336.

Funnel separating VD-1−50 (100) TC GOST 25336 or VD-2−100 TC GOST 25336.

Footwear of any type of the 2nd accuracy class with the error of weighing according to GOST 24104.

Cups of glassy carbon.

Volumetric flasks 2−25 (100, 50, 1000) — 2 according to GOST 1770.

Pipette 8−2-0,2 according to GOST 20292.

Pipette 4−2-2 GOST 20292.

Nitric acid according to GOST 4461 or nitric acid high purity according to GOST 11125, diluted 2:1.

Sulfuric acid according to GOST 4204, a solution of 0.5 mol/DM.

Hydrochloric acid according to GOST 3118 and diluted 1:9.

Glycerin according to GOST 6259.

Tin dichloride, solution 100 g/lin glycerol; solution 40 g/lin hydrochloric acid, diluted 1:9.

Potassium permanganate according to GOST 20490, a solution of 50 g/DM.

Chloroform according to GOST 20015, distilled.

The 1-butanol according to GOST 6006, distilled at a temperature of 118 °C.

The mixture for the extraction of: 30 cmof 1-butanol are mixed with 70 cmof chloroform.

Copper according to the GOST 859.

Potassium phosphate according to GOST odnosemjannyj 4198, dried to constant weight at a temperature of 80−90 °C.

Sodium phosphate disodium GOST 11773, dried to constant weight at a temperature of 102−105 °C.

The mixture of acids to dissolve: mix nitric and hydrochloric acids in a ratio of 1:3.

Ammonia water according to GOST 3760.

Ammonium molybdate according to GOST 3765 (recrystallized), a solution of 100 g/DM.

Restoration mix: mix before use, 50 cm ina freshly prepared solution of tin dichloride in hydrochloric acid and 450 cmof sulphuric acid with molar concentration 0.5 mol/

DM.

10.2. Preparation for assay

10.2.1. Preparation of standard solutions

Solution a: a sample of sodium phosphate twosemester weight 0,4580 g or potassium phosphate of single mass 0,4393 g is placed in a measuring flask with volume capacity of 1000 cm, pour 100−150 cmof water and bring to the mark with water.

1 cmof solution A contains 0.1 mg of phosphorus.

Solution B: aliquot part 10 cmof the solution And placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

1 cmof a solution contains 0.01 mg of phosphorus. The solution is prepared the day of analysis.

The standard solutions of phosphorus stored in a plastic container.

10.2.2. Construction of calibration curve

In the separating funnel is placed 0,0; 0,10; 0,20; 0,50; 1,00; 1,5 and 2.0 cmstandard solution B, which corresponds to 0,0; 0,001; 0,002; 0,005; 0,010; 0,015 and 0.020 mg of phosphorus.

To each funnel pour 3 cmof hydrochloric acid for 7-cmwater, 5 cmof molybdenic acid ammonium solution and then perform the extraction as described in section 10.3.1.

According to the obtained results build a calibration curve in rectangular coordinates.

10.3. Analysis

10.3.1. Two sample of copper weighing 1,000 grams is placed in a Cup of glassy carbon or glasses with a capacity of 100 or 150 cm(or conical flask). One Cup or glass of an additive injected standard solution of phosphorus, the amount of which is chosen so that the analytical signal component is increased 2−3 times compared to the analytical signal in the absence of additives. Flow 0,1−0,3 cmof a solution of potassium permanganate and 10 cmof nitric acid, diluted 2:1. Heated to dissolve the sample and then evaporated to dry salts. The residue is dissolved in 3 cmof hydrochloric acid and 7 cmwater. To the obtained solution add 5 cmof ammonium molybdate solution and allowed to stand for 5−7 min.

Then transferred to a separatory funnel, add 20 cmto the mixture for extraction, and extracted for 2 min. After separation of the layers the organic phase is placed in a volumetric flask with a capacity of 25 cm, poured one drop of a solution of tin dichloride and diluted to the mark with the mixture for extraction and mixed.

Measure the optical density of the extract on a spectrophotometer or photoelectrocolorimeter at a wavelength of 620−630 nm in a cuvette with a layer thickness of 30 or 50 mm. Solution comparison is the mixture for extraction.

The mass of phosphorus determined according to the calibration schedule. A lot of phosphorus additives find as the difference between the found mass of phosphorus in the sample with the additive and a sample without extras

I.

10.3.2. A sample of copper weighing 1,000 grams is placed in a glass (or conical flask) with a capacity of 250 cm, flow of 0.1−0.3 cmpotassium permanganate, and 20 cmof the mixture of acids to dissolve. Heated to dissolve the sample. Cooled, poured 20−30 cmof water, mix. Placed in a separating funnel with a capacity of 100−150 cm, dilute with water to volume of 50 cm, neutralized with ammonia solution to pH~5 (for universal indicator paper), up to 4 cmboiled nitric acid, 5 cmof molybdate ammonium solution, stirred and incubated for 10 min.

Then add 10 cmto the mixture for extraction and extracted 2 minutes After the separation of the liquids, the organic layer drained into another separatory funnel with a capacity of 100 cm, and to the water add 10 cmto the mixture for extraction, and repeat the extraction. The organic layer decanted into a separatory funnel, which is the first extract, and the aqueous layer discarded.

To the combined extracts poured 20 cmof restorative mixture and vigorously shaken for 1 min. After separation the aqueous layer is placed in a volumetric flask with a capacity of 25 cmand was adjusted to the mark with water. The organic layer discarded.

After 5 min measure the optical density of the solution on the spectrophotometer at a wavelength of 780 nm in a cuvette with a layer thickness of 10 mm.

Solution comparison is the solution of the reference experiment.

A lot of phosphorus is determined by calibration g

Rafik.

10.4. Processing of the results

10.4.1. Mass fraction of phosphorus () in percent is calculated by the formula

,

where is the mass of phosphorus in the solution of the sample, was found in the calibration graphics mg;

 — weight of copper,

10.4.2. Allowable absolute discrepancies in the results of two parallel determinations for sample analysis at a confidence level =0.95 is (the rate of convergence) and the results of the analysis of the same samples obtained in two laboratories and one reference laboratory, but under different conditions (a measure of reproducibility) shall not exceed the permissible values given in table.12.

Table 12

10.4.3. Control of the correctness of the results of the analysis carried out in accordance with PP.2.4.3, 2.4.4.