GOST 11739.17-90

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  ГОСТ 11739.17-90

GOST 11739.17−90 Alloys aluminium cast and wrought. Methods for determination of tin

GOST 11739.17−90

Group B59

STATE STANDARD OF THE USSR

ALLOYS ALUMINIUM CAST AND WROUGHT

Methods for determination of tin

Aluminium casting and wrought alloys.
Methods for determination of tin

AXTU 1709

Valid from 01.07.91
before 01.07.96*
_______________________________
* Expiration removed
Protocol 5−94 N Interstate Council
for standardization, Metrology and certification
(IUS N 11/12, 1994). — Note the manufacturer’s database.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of aviation industry of the USSR

DEVELOPERS

V. G. Davydov, doctor of engineering. Sciences; V. A. Moshkin, PhD. tech. Sciences; G. I. Friedman, PhD. tech. Sciences; V. I. Klitina, PhD. chem. Sciences; M. N. Gorlova, PhD. chem. Sciences; O. L. Sikorska, PhD. chem. Sciences; L. N. Viksne

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 28.06.90 N 1962

3. The frequency of inspection — 5 years

4. REPLACE GOST 11739.17−78

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies the photometric (with mass fraction of tin from 0.005 to 0.1%) and atomic absorption (at a mass fraction of tin from 0.01 to 1.0%) methods for determination of tin.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 25086 with the Supplement.

1.1.1. For the results analysis be the arithmetic mean of results of two parallel measurements.

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF TIN

2.1. The essence of the method

The method is based on dissolving the sample in a solution of sodium hydroxide, the formation after the neutralization of sulfuric acid in water-ethanol medium orange complex tin with phenylfluorone, stabilize the gelatin and measuring the optical density of the solution at a wavelength of 540 nm.

2.2. Apparatus, reagents and solutions

Spectrophotometer or photoelectrocolorimeter.

a pH meter.

Sodium hydroxide according to GOST 4328, a solution of 250 g/DM.

Sulfuric acid according to GOST 4204, density 1.84 g/cmand a solution of 1:1, 1:4.

Ammonia water according to GOST 3760, density of 0.91 g/cmand a solution of 1:1.

Phenolphthalein, alcohol solution 1 g/DM.

Tartaric acid according to GOST 5817, a solution of 50 g/DM.

Aminouxusna acid according to GOST 5860.

Ascorbic acid, a solution of 20 g/DMfreshly prepared.

Gelatin GOST 11293*, a solution of 5 g/DMfreshly prepared: 0.5 g of gelatin is added to 100 cmof water heated to a temperature of (70±5) °C, and dissolved under constant stirring.
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* On the territory of the Russian Federation GOST 11293−89. — Note the manufacturer’s database.

The technical rectified ethyl alcohol according to GOST 18300.

Phenylfluorone on the other 6−09−05−289 (use the product only pink), alcohol solution of 0.3 g/DM: 0.03 g phenylfluorone placed in a beaker with a capacity of 50 cm, add 1 cmof sulfuric acid solution (1:1), triturated with a glass rod until a homogeneous mass. Then pour the 20−25 cmof ethanol, mixed well and transferred to a volumetric flask with a capacity of 100 cm, wash the glass with alcohol, poured into a flask, add the solution in the flask with ethanol up to the mark and mix.

Sodium chloride according to GOST 4233.

Hydrochloric acid according to GOST 3118, density of 1.19 g/cm, solution 0,1 mol/DM.

Buffer solution with a pH of 1.6: 7,507 g aminouxusna acid and 5.85 g of sodium chloride were placed in a glass with a capacity of 200 cmand dissolve in water. The solution was transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix. Then to 38 cmof this solution was added 62 cmhydrochloric acid solution and stirred. The resulting buffer solution to control pH-meter.

Aluminium GOST 11069* brand А999.
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* On the territory of the Russian GOST 11069−2001, here and hereafter. — Note the manufacturer’s database.

Tin GOST 860 brand 01.

A standard solution of tin: 0.1 g of tin are placed in a beaker with a capacity of 100 cm, was dissolved with heating in 10 cmof sulphuric acid, evaporated the solution until the appearance of white fumes, cooled, poured 20 cmof sulfuric acid solution (1:4) and dissolved salts when heated. The solution was cooled, transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with the same solution of sulfuric acid and stirred.

1 cmof the solution contains 0.0001 g of tin.

2.3. Analysis

2.3.1. A portion of sample weighing 0.5 g is placed in a conical flask with a capacity of 100 cm, pour the 12.5 cmof sodium hydroxide and dissolve first at room temperature and then under low heat. Upon completion of the dissolution solution and the precipitate was transferred to a volumetric flask with a capacity of 250 cm, made up to the mark with water and mix. The solution was filtered through a filter medium density («white ribbon»), discarding first portion of filtrate.

2.3.2. Select 20 cmof the filtered solution was placed in a volumetric flask with a capacity of 50 cm, neutralized with sulfuric acid (1:1) to phenolphthalein, add 2cmof a solution of tartaric acid, neutralize the excess ammonia solution (1:1) (solution turns pink from 1−2 drops), add 0.7 cmof sulfuric acid solution (1:1), 1 cmof ascorbic acid solution and 2 cmof gelatin solution. After each addition of reagent solution mix thoroughly.

Immediately prior to measurement of optical density in a flask add 2 cmof solution phenylfluorone and 5 cmbuffer solution, made up to the mark with water and mix

T.

2.3.3. The optical density of the sample solution is measured after 5 min at a wavelength of 540 nm in a cuvette with a layer thickness of 50 mm. Solution comparison the solution serves as the reference experiment.

2.3.4. The solution in the reference experiment is prepared according to claim.2.3.1, 2.3.2, using is sample the sample the sample of aluminium.

Mass fraction of tin is calculated according to the calibration schedule.

2.3.5. Construction of calibration curve

Eight conical flasks with a capacity of 100 cmplaced aluminium sample weight of 0.5 g and after the dissolution of batches of 12.5 cmof sodium hydroxide solution in seven of them consistently measure 0,25; 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution, which corresponds to 0,000025; 0,00005; 0,0001; 0,0002; 0,0003; 0,0004; 0,0005 g tin. Then transfer the solutions into volumetric flasks with a capacity of 250 cm, made up to the mark with water, mix and continue at PP.2.3.2, 2.3.3. Solution not containing the tin, serves as a solution control experience in construction of calibration curve.

According to the obtained values of optical density of the solutions and the respective masses of tin to build a calibration curve.

2.4. Processing of the results

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

, (1)

where  — weight of tin in the sample solution found by the calibration schedule g;

 — the weight of the portion of the sample,

2.4.2. Discrepancies in the results must not exceed the values given in table.1.

Table 1

3. ATOMIC ABSORBTSIONNYI METHOD FOR DETERMINATION OF TIN

3.1. The essence of the method

The method is based on dissolving the samples in hydrochloric acid in the presence of hydrogen peroxide and subsequent measurement of the atomic absorption of tin at a wavelength of 286,3 nm in a flame acetylene-nitrous oxide. Method is used for alloys with a mass fraction of silicon not more than 1%.

3.2. Apparatus, reagents and solutions

Spectrophotometer of atomic absorption with a radiation source for tin.

Acetylene according to GOST 5457.

Nitrous oxide medical.

Hydrochloric acid according to GOST 3118, density of 1.19 g/cmand a solution of 1:1 and 1:19.

Nickel chloride according to GOST 4038, a solution of 1 g/DM.

Hydrogen peroxide according to GOST 10929.

Aluminium GOST 11069 brand А999.

A solution of aluminium 40 g/l: 20 g of aluminum is placed in a beaker with capacity of 500 cm, add 50 cmof water and small portions of 300 cmof a hydrochloric acid solution (1:1) and dissolve with a moderate heat, adding 1 cmof solution of chloride Nickel. The solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

Tin GOST 860 brand 01.

Standard solutions of tin

Solution a: 1 g of tin is placed in a tall glass with a capacity of 600 cm, add 200 cmof hydrochloric acid, cover with watch glass, and dissolve by heating in the presence of platinum at a temperature not exceeding 80 °C, without bringing the solution to boiling.

The solution was cooled to room temperature, transferred into a measuring flask with volume capacity of 1000 cm, made up with hydrochloric acid 1:19 up to the mark, mix.

1 cmof the solution contains 0.001 g of tin.

Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, flow 10 cmof hydrochloric acid (1:1), add a solution of hydrochloric acid (1:19) to the mark and mix; cook before eating.

1 cmof a solution contains 0,000

1 g tin.

3.3. Analysis

3.3.1. A portion of the sample weighing 1 g is placed in a conical flask with a capacity of 250 cm, pour approximately 10 cmof water and then small portions of 30 cmof a hydrochloric acid solution (1:1). The beaker cover watch glass, and dissolve in low heat until complete dissolution of the sample. Add 3−5 drops of hydrogen peroxide and boil the solution for 3 min.

Watch glass and walls of the flask rinsed with water. The solution was cooled to room temperature, transferred to a volumetric flask with a capacity in accordance with table.2, add a solution of hydrochloric acid (1:19) to the mark and mix.

Table 2

The resulting solution if it is not transparent, was filtered through a dry filter medium density (white ribbon) in a beaker, discarding the first portions of the filtrate.

3.3.2. The solution in the reference experiment is prepared according to claim 3.3.1, using is sample the sample the sample of aluminium.

3.3.3. Construction of calibration graphs

3.3.3.1. When the mass fraction of tin from 0.01 to 0.1% in six volumetric flasks with a capacity of 50 cm25 cm pour thesolution of aluminium, in five of them measure 1,0; 2,5; 5,0; 7,5; 10,0 cmstandard solution B, which corresponds to 0,0001; 0,00025; 0,0005; 0,00075; 0.001 g of tin.

3.3.3.2. When the mass fraction of tin in excess of 0.1 to 0.5% in six volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminium, in five of them measure 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution A, which corresponds to 0,001; 0,002; 0,003; 0,004; 0.005 g of tin.

3.3.3.3. When the mass fraction of tin, more than 0.5 to 1.0% in seven volumetric flasks with a capacity of 100 cmpoured in 12.5 cmof a solution of aluminum in six of them measure 2,5; 3,0; 3,5; 4,0; 4,5; 5,0 cmstandard solution A, which corresponds to 0,0025; 0,003; 0,0035; 0,004; 0,0045; 0,005 g tin.

3.3.3.4. The solutions in flasks in PP.3.3.3.1, 3.3.3.2 and 3.3.3.3 is poured a solution of hydrochloric acid (1:19) to mark and mix.

3.3.4. The sample solution, solution control experience and solutions to build the calibration curve is sprayed into the flame of acetylene-nitrous oxide and measure the atomic absorption of tin at a wavelength of 286,3 nm.

According to the obtained values of atomic absorption and corresponding mass concentrations of tin build a calibration curve.

The mass concentration of tin in the sample solution and the solution of control and experience determined by the calibration schedule.

3.4. Processing of the results

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

, (2)

where is the mass concentration of tin in the sample solution found by the calibration schedule, g/cm;

 — mass concentration of tin in solution in the reference experiment, was found in the calibration schedule, g/cm;

 — the volume of the sample solution, cm;

 — weight of sample, g

.

3.4.2. Discrepancies in the results must not exceed the values given in table.3.

Table 3