GOST 1953.11-79

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  ГОСТ 1953.11-79

GOST 1953.11−79 Bronze tin. Methods for determination of bismuth (with Amendments No. 1, 2)

GOST 1953.11−79

Group B59

INTERSTATE STANDARD

BRONZE TIN

Methods for determination of bismuth

Tin bronze.
Methods for the determination of bismuth

AXTU 1709

Date of introduction 1981−01−01

INFORMATION DATA

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

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 10.10.79 N 3899

3. The standard fully complies ST SEV 1540−79

4. REPLACE GOST 1953.11−74

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Limitation of actions taken by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification (ICS 11−12−94)

7. EDITION with Amendments No. 1, 2 approved in February 1983, August 1990 (IUS 6−83, 11−90)

This standard establishes photometric (from 0.001% to 0.02%) and atomic absorption (0.001% to 0.02%) methods for determination of bismuth in tin bronze according to GOST 5017.

The standard fully complies ST SEV 1540−79.

(Changed edition, Rev. N 1, 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 25086 with the Supplement according to claim 1.1 GOST 1953.1.

(Changed edition, Rev. N 1, 2).

2A. The PHOTOMETRIC METHOD for the DETERMINATION of BISMUTH (0.001% to 0.02%)

2A.1. The essence of the method

The method is based on the formation of bismuth with selenology orange coloured complex and the measurement of its optical density after preliminary isolation of bismuth by coprecipitation with ferric hydroxide or with manganese dioxide 1.5 mol/DMnitric acid. The interfering influence of iron is removed with ascorbic acid, and traces of tin — sodium fluoride.

Sec. 2A. (Added, Rev. N 1).

2. APPARATUS, REAGENTS AND SOLUTIONS

Photoelectrocolorimeter or spectrophotometer.

Nitric acid according to GOST 4461 and solutions 1 mol/l, 0.1 mol/land diluted 1:1.

Bromatologia acid according to GOST 2062.

The acid chloride.

Ascorbic acid (vitamin C) freshly prepared solution, 100 g/DM.

Nitric acid according to GOST 4461, 1.5 mol/DMsolution.

Manganese nitrate for ND, a solution of 50 g/DM.

Potassium permanganate according to GOST 20490, a solution of 6 g/DM.

Hydrogen peroxide (perhydrol) according to GOST 10929.

Copper with a mass fraction of bismuth less than 0.0005%.

Copper nitrate, a solution of 20 g/DM; prepared as follows: 2 g of copper is dissolved in 20 cmof nitric acid, diluted 1:1, and remove the oxides of nitrogen by boiling, the solution cooled and top up with water to 100 cm.

Ammonia water according to GOST 3760 and diluted 1:50.

Bromine according to GOST 4109.

Mix to dissolve, freshly prepared; prepared as follows: nine volumes bromatological acid is mixed with one volume of bromine.

Iron chloride according to GOST 4147, a solution of 1 g/DM, is prepared as follows: 1 g of ferric chloride dissolved in 250 cmof hydrochloric acid diluted 1:1 and top up with water to 1 DM.

Sodium fluoride according to GOST 4463, a solution of 5 g/DM.

Selenology orange, solution 1 g/lin 0.1 mol/DMnitric acid solution.

Bismuth GOST 10928, brand Ви0.

Standard solutions of bismuth.

Solution A, prepared as follows: 0.1 g of bismuth dissolved in 20 cmof concentrated nitric acid. Remove the oxides of nitrogen by boiling, transfer the solution into a volumetric flask with a capacity of 1 DM, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of bismuth.

Solution B is prepared as follows: pour 10 cmof solution A in a volumetric flask with a capacity of 100 cmand dilute to the mark with water.

1 cmof solution B contains 0,00001 g of bismuth.

(Changed edition, Rev. N 1).

3. ANALYSIS

3.1. The sample of bronze with a weight of 1 g was placed in a beaker with a capacity of 300 cm, add 15 cmof the mixture for dissolution, the beaker cover watch glass, and dissolve when heated. In case of incomplete dissolution of the sample in the solution was dropwise added bromine. Upon completion of the dissolution solution was poured to 20 cmof perchloric acid and evaporated the solution at a moderate heat to release thick white smoke and lightening solution. The solution was cooled, rinse watch glass and sides of beaker with water and repeat the evaporation until the appearance of dense white smoke of perchloric acid. The solution was cooled, rinse the walls of the beaker with a little water and heated to dissolve precipitated salts. The solution is diluted with water to 150 cm, add 10 cmof a solution of ferric chloride and concentrated ammonia solution to complete the transition of copper in a soluble ammonia complex. Solution and the precipitate was aged at 60 °C for coagulation of the precipitate hydroxides of iron and bismuth. The precipitate was filtered off on a filter of medium density. The filter cake and a glass washed 3−5 times with a hot solution of ammonia, diluted 1:50. The precipitate is washed with hot water into a glass, which was carried out the precipitation of the hydroxides of iron and bismuth, and dissolved in 20 cmof hot nitric acid diluted 1:1. The filter carefully washed with hot water. Repeat the precipitation of the hydroxides of iron and bismuth with ammonia, filtering and washing the precipitate.

The washed precipitate on the filter is dissolved in 20 cmof hot nitric acid diluted 1:1. The solution collected in the beaker in which to conduct the deposition. The filter is washed with hot water 5−7 times.

When the mass fraction of bismuth in the alloy from 0.001% to 0.008% solution is evaporated almost to dryness. When the mass fraction of bismuth of more than 0,008% solution transferred to a volumetric flask with a capacity of 25 cm, top up to the mark with water and mix. Aliquot part of 10 cmis evaporated almost to dryness. To the residue poured 5 cm1 mol/DMnitric acid solution, rinse the walls of the Cup 5 cmof water and boil it. Add 4 cmof ascorbic acid solution, cooled, poured 1 cmof a solution of sodium fluoride, 1 cmkylinalove orange solution, the mixture is transferred into a measuring flask with a capacity of 50 cm, made up to the mark with water, mix and after 10 min measure the optical density of the solution in cuvette with thickness of the absorbing layer of 5 cm at a photoelectrocolorimeter with a green filter or on spectrophotometer at 540 nm relative to the solution, the control

wow experience.

3.1. The weight of bronze weighing 1 g is placed in a wide glass with a capacity of 250 cmand dissolved in 15 cmof the mixture to dissolve first in cold and then when heated. In case of incomplete dissolution of the sample add a few drops of bromine. Then add 10 cmof perchloric acid and evaporated to moist residue. The residue is cooled, diluted with water to 50 cm. Add 5 cmof a solution of nitrate of manganese, the solution is neutralized with ammonia until the appearance of the precipitate copper hydroxide, add 18 cmof nitric acid, diluted 1:1, and water to a volume of 90 cm. The solution is heated nearly to boiling, add 10 cmof a solution of potassium permanganate, and boil for 2 min. After 30 min the precipitate was filtered on a tight filter and washed the beaker and the precipitate 8−10 times hot of 1.5 mol/DMnitric acid until the disappearance of the blue color formed of copper nitrate. The deployed filter is washed with water in a glass, which held a selection, the filter is washed with 20 cmof hot nitric acid diluted 1:1 containing several drops of hydrogen peroxide solution and then with water. Further analysis are as indicated in claim 3.1.

(Added, Rev. N

1).

3.2. Construction of calibration curve

In glasses with a capacity of 50 cmis placed 0; 1,0; 2,0; 4,0; 6,0 and 8,0 cmstandard solution B of bismuth and evaporated to near dryness. To the dry residue poured 5 cm1 mol/DMnitric acid and then act as described in paragraph 3.1. A solution of comparison, using the solution containing no bismuth.

4. PROCESSING OF THE RESULTS

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

,

where  — weight of bismuth, was found in the calibration schedule g;

the weight of bronze,

4.2. Discrepancies in the results of parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3), specified in the table.

(Changed edition, Rev. N 2).

4.3. Discrepancies in the results analysis, obtained in two different laboratories or two of the results obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values given in the table.

4.4. Control of accuracy of analysis results is carried out according to State standard samples of tin bronzes, re-approved by GOST 8.315, or a comparison of the results obtained by atomic absorption method, in accordance with GOST 25086.

4.3, 4.4. (Added, Rev. N 2).

5. ATOMIC ABSORPTION METHOD for the DETERMINATION of BISMUTH (0.001% to 0.02%)

5.1.The essence of the method

The method is based on measuring the absorption of light by atoms of bismuth, formed by the introduction of the analyzed solution in the flame acetylene-air, after pre-allocation of bismuth to manganese dioxide.

5.2. Apparatus, reagents and solutions

Atomic absorption spectrometer with a radiation source for bismuth.

Nitric acid according to GOST 4461, diluted 1:1, 2 mol/land 1.5 mol/DMsolutions.

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

Hydrochloric acid according to GOST 3118, 1 mole/DMsolution.

Ammonia water according to GOST 3760.

Manganese nitrate for ND, a solution of 20 g/DM.

Potassium permanganate according to GOST 20490, a solution of 6 g/DM.

Hydrogen peroxide (perhydrol) according to GOST 10929.

Bismuth GOST 10928 with a mass fraction of bismuth is not less than 99.9%.

Standard solutions of bismuth.

Solution A, prepared as follows: 0.25 g of bismuth was dissolved with heating in 20 cmof nitric acid, diluted 1:1, the solution was cooled, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water.

1 cmof the solution contains 0.0005 g of bismuth.

Solution B is prepared as follows: 10 cmof solution A is placed in a volumetric flask with a capacity of 100 cm, add 10 cmof 2 mol/DMnitric acid and add water to the mark.

1 cmof a solution of 0.00005 g contains bismuth.

Solution; prepared as follows: 20 cmof solution B is placed in a volumetric flask with a capacity of 100 cm, add 10 cmof 2 mol/DMnitric acid and add water to the mark.

1 cmof the solution contains 0,0000

1 g of bismuth.

5.3. Analysis

5.3.1. The weight of bronze weighing 2 g were placed in a glass with a capacity of 250 cmand dissolved by heating in 20 cmof nitric acid, diluted 1:1. Nitrogen oxides are removed by boiling and the solution diluted with water to a volume of 50 cm. Add 5 cmof a solution of nitrate of manganese, the solution is neutralized with ammonia until the appearance of the precipitate copper hydroxide, add 18 cmof nitric acid, diluted 1:1, and water to a volume of 90 cm. The solution is heated to boiling, add 10 cmof a solution of potassium permanganate, and boil for 2 min. after 30 min the precipitate was filtered off on a tight filter and washed the beaker and the precipitate 4−5 times a hot 1.5 mol/DMsolution of nitric acid. The deployed filter is washed with water in a glass, which conducted the deposition, the filter is washed with 10 cmof hot sulfuric acid solution, diluted 1:4 with a few drops of solution of hydrogen peroxide, water. And then rinsed the filter is discarded and the solution is evaporated to wet salts. After cooling, add 8 cm1 mol/DMhydrochloric acid solution, transferred to a volumetric flask with a capacity of 100 cmand topped to the mark of 1 mol/DMhydrochloric acid solution.

Measure the atomic absorption of bismuth in the flame acetylene-air at a wavelength of 223,1 nm parallel calibration Rast

thieves.

5.3.2. Construction of calibration curve

In eight of the nine cups with a capacity of 250 cmis placed 1,0; 2,5; 5,0 and 10,0 cmstandard solution Into and 4,0; 6,0; 8,0 and 10,0 cmstandard solution B.

In all the cups add water to a volume of 50 cm, add 5 cmof a solution of manganese nitrate and further analysis are as indicated in claim 5.3.1. According to the obtained results build a calibration curve.

5.4. Processing of the results

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

,

where is the concentration of bismuth was found in the calibration schedule, g/cm;

 — the volume of the final sample solution, cm;

 — the weight of the portion,

5.1−5.4.1. (Changed edition, Rev. N 1).

5.4.2. Discrepancies in the results of parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3), specified in the table.

(Changed edition, Rev. N 2).

5.4.3. Discrepancies in the results analysis, obtained in two different laboratories or two of the results obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values given in the table.

5.4.4. Control of accuracy of analysis results is conducted by State standard samples of tin bronzes, re-approved by GOST 8.315, or a comparison of the results obtained by the photometric method according to GOST 25086.

5.4.3, 5.4.4. (Added, Rev. N 2).

6. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF BISMUTH WITH THE USE OF POTASSIUM IODIDE

6.1. The essence of the method

The method is based on the formation of bismuth with iodide of potassium colored complex and measurement of its optical density after prior removal of tin in the form of tetrabromide and the allocation of bismuth by coprecipitation with ferric hydroxide. To restore odeneho complex used thiourea, which is still masking reagent, forming colourless complexes with iron, copper, Nickel.

6.2. Equipment, reagents, solutions

Photoelectrocolorimeter or spectrophotometer.

Nitric acid according to GOST 4461, diluted 3:2.

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

Sulfuric acid according to GOST 4404* diluted 1:3.
_____________
* Probably a mistake of the original. Should read GOST 4204. — Note the CODE.

The acid chloride.

Bromatologia acid according to GOST 2062.

Bromine according to GOST 4109.

Mix to dissolve, freshly made: nine volumes bromatological acid is mixed with one volume of bromine.

Ammonia water according to GOST 3760 and diluted 1:20.

Ammonium chloride according to GOST 3773, a solution of 200 g/DM.

Sodium carbonate crystal according to GOST 84.

Sodium fluoride according to GOST 4463, a solution of 40 g/DM.

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

Thiourea according to GOST 6344, solution 100 g/DM.

Iron chloride according to GOST 4147, a solution of 10 g/DM: 1 g of ferric chloride dissolved in 25 cmof hydrochloric acid (1:1) and top up with water to 100 cm.

Bismuth GOST 10928 brand Ви0.

Standard solutions of bismuth.

Solution A; 0.1 g of bismuth dissolved in 20 cmof nitric acid (3:2), oxides of nitrogen are removed by boiling, the solution was transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of bismuth.

Solution B: 20 cmsolution And placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmof solution B contains 0,00002 g

isata.

6.3. Analysis

6.3.1. The sample of bronze with a weight of 1 g was placed in a beaker with a capacity of 300 cm, add 15−20 cmof the mixture for dissolution, the beaker cover watch glass, and dissolve when heated. In case of incomplete dissolution of the sample in the solution was dropwise added bromine. Upon completion of the dissolution poured to the solution of 20−30 cmof perchloric acid and evaporated the solution at a moderate heat to release thick white smoke and lightening solution. The solution was cooled, rinse watch glass and sides of beaker with water and repeat the evaporation until the appearance of dense white smoke of perchloric acid. The solution was cooled, rinse the walls of the beaker with a little water and heated to dissolve precipitated salts. The solution is diluted with water to 100−150 cm, add 10 cmof a solution of ferric chloride, 20 cmof a solution of ammonium chloride, heated to 70−80 °C, add 1 g of sodium carbonate and concentrated ammonia until full transfer of copper in a soluble ammonia complex. Solution and the precipitate was aged at 60 °C for coagulation of the precipitate of iron hydroxide and bismuth. The precipitate was filtered off on a filter of medium density. The precipitate on the filter and the beaker was washed 5 times with hot ammonia solution (1:20). The precipitate is washed with hot water into a glass, which was carried out the precipitation of the hydroxides of iron and bismuth, and dissolved in 20 cmof hot hydrochloric acid (1:1). If in the bronze there is manganese, by dissolving the precipitate add a few drops of hydrogen peroxide. The filter carefully washed with hot water. Repeat the precipitation of the hydroxides of iron and of bismuth, filtering, washing, dissolving the precipitate and washing of the filter.

When the mass fraction of bismuth in bronze from 0.001% to 0.008% solution is evaporated almost to dryness, but it is not; it burns. When the mass fraction of bismuth of more than 0,008% solution transferred to a volumetric flask with a capacity of 25 cm, top up to the mark with water, mix, take aliquot part — 10 cmand evaporated to near dryness, but not; it burns. To the residue is added 2.2 cmof sulphuric acid (1:3), 10 cmwater, 1 cmof a solution of thiourea and leave for 1 h. the Solution was transferred to a volumetric flask with a capacity of 25 cm, add 1 cmof a solution of sodium fluoride, 1 cmof a solution of potassium iodide, made up to the mark with water and mix. After 5 min measure the optical density of the solution on the spectrophotometer at 465 nm or photoelectrocolorimeter with a blue filter in a cell with thickness of the absorbing layer 5 cm* using water as a solution of comparison. Through all stages of the analysis spend control experience.

_________________

* Consistent with the original. — Note the CODE.

6.3.2. Construction of calibration curve

In a volumetric flask with a capacity of 25 cmis placed 0; 0,5; 1,0; 2,0; 2.5 cmstandard solution B of bismuth, added 2.2 cmof sulphuric acid (1:3) and then do as specified in clause 6.3.1. A solution of comparison, using the solution containing no bismuth.

6.4. Processing of the results

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

,

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

 — the mass of bismuth in the control sample, was found in the calibration schedule g;

the weight of bronze or the weight of the portion corresponding to aliquote part of the solution,

6.4.2. Discrepancies in the results of parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3), specified in the table.

6.4.3. Discrepancies in the results analysis, obtained in two different laboratories or two of the results obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values given in the table.

6.4.4. Control of accuracy of analysis results is carried out according to State standard samples of tin bronzes, re-approved by GOST 8.315, or a comparison of the results obtained by atomic absorption method, in accordance with GOST 25086.

Sec. 6. (Added, Rev. N 2).