GOST 11739.19-90

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  ГОСТ 11739.19-90

GOST 11739.19−90 Alloys aluminium cast and wrought. Methods for determination of antimony

GOST 11739.19−90

Group B59

STATE STANDARD OF THE USSR

ALLOYS ALUMINIUM CAST AND WROUGHT

Methods for determination of antimony

Aluminium casting and wrought alloys.
Methods for determination of antimony

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 11739.19−78

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies the photometric (with a mass fraction of antimony from from 0.0002 to 0.01%) and atomic absorption (at a mass fraction of antimony from 0.01 to 0.3%) methods for determination of antimony in alloys with a mass fraction of silicon not more than 1%.

1. GENERAL REQUIREMENTS

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

1.1.1. 3a the result of the analysis be the arithmetic mean of results of two parallel measurements.

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ANTIMONY

2.1. The essence of the method

The method is based on dissolving the sample in a mixture of hydrochloric, nitric and sulphuric acids, the formation of the complex of antimony in the form of charantimath with diamond green, extraction of the complex with toluene, and measuring optical density are painted in a bluish-green color of the extract at a wavelength of 670 nm.

2.2. Apparatus, reagents and solutions

Spectrophotometer or photoelectrocolorimeter.

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

Nitric acid according to GOST 4461, density 1,35−1,40 g/cm.

Sulfuric acid according to GOST 4204, density 1.84 g/cmand a solution of 1:4, 1:10.

A mixture of hydrochloric and nitric acids in the ratio (3:1). The mixture was diluted (1:1), prepared immediately before use.

Tin dichloride, and the solution 250 g/l: 25 g of tin dichloride are dissolved in 20 cmof a hydrochloric acid solution (1:1), top up with water to 100 cmand mixed.

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

Urea according to GOST 6691, saturated solution: 100 g of urea dissolved in 100 cmof hot water and cooled.

The technical rectified ethyl alcohol according to GOST 18300.

Brilliant green on the other 6−09−3057, a solution of 5 g/DM: 0.5 g of brilliant green are dissolved in 25 cmof ethanol, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

Toluene according to GOST 5789.

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

Antimony GOST 1089.

Standard solutions of antimony.

Solution a: 0.1 g of metallic antimony is dissolved in 30 cmof sulfuric acid under heating, cooled. The solution is transferred into a measuring flask with volume capacity of 1000 cm, containing 400 cmof sulfuric acid solution (1:4). The solution was cooled to room temperature, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of antimony.

Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, top up with sulphuric acid solution (1:10) to the mark and mix; prepare immediately before use.

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

Solution In 20 cmof a solution transferred to a volumetric flask with a capacity of 100 cm, top up with sulphuric acid solution (1:10) to the mark and mix; prepare immediately before use.

1 cmof the solution contains 0,0

00002 g of antimony.

2.3. Analysis

2.3.1. Weighed samples weighing 0.5 g were placed in a glass with a capacity of 250−300 cm, 30 cm, pour themixture of hydrochloric and nitric acids and 10 cmof sulphuric acid. A glass cover glass and the sample is dissolved with moderate heating. Without removing the glass, the solution was evaporated prior to the allocation of steams of sulfuric acid and cooled to room temperature.

2.3.2. When the mass fraction of antimony from of 0.0002 to 0.002% to the content of the beaker was added 15 cmof a hydrochloric acid solution, washing the glass and the side of the Cup; heated to dissolve the salts, cooled to room temperature and pour 1−2 cmof a solution of dichloride of tin to iron reduction (bleaching solution). Then add in a glass of 4−7 cmof a solution of sodium attestatio to establish an unchanging yellow color of the solution and, periodically stirring the solution, let it stand for 3 min. To the solution poured 1 cmof a saturated solution of urea, stirred and poured it into a separatory funnel with a capacity of 250 cm. Add in the funnel 50−60 cmof water, 0.5 cmof a solution of brilliant green, 10 cmof toluene and vigorously shake the funnel for 1 min, allow the phases to settle for 0.5 min, the aqueous phase is discarded and organic (extract) was filtered through cotton wool in a dry flask with a capacity of 25 cmwith a cork or Cuvee

Tu.

2.3.3. When the mass fraction of antimony from 0.002 to 0.01% to the content of the beaker was added 15 cmof a hydrochloric acid solution, washing the glass and the walls of the glass, gently heated to dissolve the salts, and cooled to room temperature. The solution was transferred to volumetric flask with a capacity of 50 cm, was added a solution of hydrochloric acid to the mark and mix. Pipetted 10 cmresulting solution was placed in a beaker with a capacity of 250−300 cm, add 4 cmof sulphuric acid, 1−2 cmof a solution of tin dichloride to a bleaching solution, a 4 cmsolution azotistykh sodium and continue according to claim 2.3.2

.

2.3.4. The optical density of the extract was measured immediately after extraction at a wavelength of 670 nm in a cuvette with a layer thickness of 10 mm.

Solution comparison is toluene.

2.3.5. The solution in the reference experiment is prepared according to claim.2.3.1, 2.3.2, 2.3.3, using is sample the sample the sample of aluminium. The optical density of the extract in the reference experiment is subtracted from the optical density of the extract samples. Mass fraction of antimony calculated according to the calibration schedule.

2.3.6. Construction of calibration curve

Seven of cups with a capacity of 250−300 cmplaced aluminium sample weight of 0.5 g, poured in 30 cmof a mixture of hydrochloric and nitric acids and 10 cmof sulphuric acid and six cups measure 0,5; 1,0; 2,0; 3,0; 5,0; 7,0 cmstandard solution, which corresponds to 0,000001; 0,000002; 0,000004; 0,000006; 0,00001; 0,000014 g of antimony. Glasses cover watch glass, and dissolve the sample in moderate heat. The solutions were evaporated to the first appearance of vapors of sulfuric acid and cooled to room temperature. Then pour 15 cmof a hydrochloric acid solution, heated to dissolve the salts, cooled to room temperature and then in accordance with clause 2.3.2. Solution not containing antimony, serves as a solution control experience in construction of calibration curve.

According to the obtained values of optical density of the extracts and their corresponding masses of antimony building a calibration curve.

2.4. Processing of the results

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

, (1)

where is the mass of antimony in aliquote part of the solution or in the whole sample, was found in the calibration schedule g;

 — the weight of the portion of the sample in aliquote part of the solution or in the whole sample,

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

Table 1

3. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF ANTIMONY

3.1. The essence of the method

The method is based on dissolving the sample in a mixture of hydrochloric, nitric and sulphuric acids and subsequent measurement of the atomic absorption of antimony at a wavelength of 217,6 nm in the oxidizing flame acetylene-air.

3.2. Apparatus, reagents and solutions

Spectrophotometer of atomic absorption with a radiation source for antimony.

Acetylene according to GOST 5457.

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

Nitric acid according to GOST 4461, density 1,35−1,40 g/cm, a solution of 1:1.

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

A mixture of acids consisting of solutions of hydrochloric (1:1), nitric and sulphuric acids in equal volumes.

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

Aluminium GOST 11069 brand А999.

A solution of aluminum 20 g/DM: 10 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 of 1:1 and dissolved at 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.

Antimony GOST 1089 (mass fraction of antimony should be not less than 99.9%).

Standard solution of antimony: 0.1 g of metallic antimony is dissolved in 20 cmof sulphuric acid at a moderate heat.

The solution was cooled to room temperature and transferred into a measuring flask with volume capacity of 1000 cm, containing 400 cmof sulfuric acid solution. The solution was topped to the mark with water and mix.

1 cmstandard solution contains 0.0001 g

antimony.

3.3. Analysis

3.3.1. A portion of sample weighing 0.5 g is placed in a conical flask with a capacity of 250 cm, flow 10 cmof water and then small portions of 25 cmof the mixture of acids. The beaker cover watch glass and heated until complete dissolution of the sample.

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 of 100 cm, is poured a solution of hydrochloric acid (1:19) to the mark and mix.

3.3.2. The 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.

3.3.3. The solution in the reference experiment is prepared according to PP.3.3.1, 3.3.2, instead of using sample sample sample aluminum.

3.3.4. Construction of calibration graphs

3.3.4.1. When the mass fraction of antimony from 0.01 to 0.1% in seven volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminum in six of them measure 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution of antimony, which corresponds to 0,00005; 0,0001; 0,0002; 0,0003; 0,0004; 0,0005 g of antimony.

3.3.4.2. When the mass fraction of antimony in excess of 0.10 to 0.30 percent in seven volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminum in six of them measure 5,0; 7,0; 9,0; 11,0; 13,0; 15,0 cmstandard solution of antimony, which corresponds to 0,0005; 0,0007; 0,0009; 0,0011; 0,0013; 0,0015 g of antimony.

3.3.4.3. The solutions in flasks in PP.3.3.4.1 and 3.3.4.2 added to 10 cmof the mixture of acids, add a solution of hydrochloric acid (1:19) to the mark and mix.

3.3.5. The sample solution, solution control experience and solutions to build the calibration curve is sprayed into the flame of acetylene-air and measure the atomic absorption of antimony at a wavelength of 217,6 nm.

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

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

3.4. Processing of the results

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

, (2)

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

 — mass concentration of antimony 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.2.

Table 2