GOST 15483.8-78

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  ГОСТ 15483.8-78

GOST 15483.8−78 (ST SEV 4806−84) Tin. Methods for determination of aluminium (with Amendments No. 1, 2, 3)

GOST 15483.8−78
(ST CMEA 4806−84)

Group B59

INTERSTATE STANDARD

TIN

Methods for determination of aluminium

Tin. Methods for determination of aluminium

AXTU 1709

Date of introduction 1980−01−01

INFORMATION DATA

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

DEVELOPERS

B. C. Baev, T. P. Almanova, G. M. Vlasov, C. B. Meshkova, L. V. Mishchenko, L. D. Savilov, R. D. Kresnicka

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 13.12.78 N 3300

3. The standard complies ST SEV 4806−84 in part by the photometric method with eryhromycin

4. REPLACE GOST 15483.8−70

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)

7. REVISED (April 1999) with Amendments No. 1, 2, 3, approved in August 1984, October 1985, June 1989 (IUS 12−84, 1−86, 10−89)


This standard establishes photometric methods for determination of aluminium (if aluminium mass fraction of from 0.0005 to 0.05%) in tin all brands except tin of high purity.

The standard complies ST SEV 4806 in part by the photometric method with eryhromycin.

(Changed edition, Rev. N 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis and security requirements — according to GOST 15483.0.

(Changed edition, Rev. N 1).

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM WITH ERYHROMYCIN R

2.1. The essence of the method

The method is based on dissolving the sample mixture and bromatological hydrochloric acid and bromine, separation of tin Stripping in the form of bromide and subsequent measurement of optical density of the complex compound of aluminum with eryhromycin at a wavelength of 530 nm.

(Changed edition, Rev. N 2).

2.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

pH meter laboratory.

Hydrochloric acid of high purity according to GOST 14261 and diluted 1:1, and 7 mol/DMsolution.

Bromatologia acid according to GOST 2062.

Bromine according to GOST 4109.

Mix to dissolve: 45 cmof hydrochloric acid, 45 cmbromatological acid and 10 cmof bromine.

Hydrogen peroxide according to GOST 10929.

Acetic acid according to GOST 61, 2 mol/DMsolution: 116 cmof glacial acetic acid is poured into a measuring flask with a capacity of 1 DM, made up to the mark with water and mix.

Nitric acid according to GOST 4461.

Ammonia water according to GOST 3760, 2 mol/DMsolution: 133 cmammonia is poured into a measuring flask with a capacity of 1 DM, is added to the mark with water and mix.

Sodium chloride according to GOST 4233.

Sodium nitrate according to GOST 4168.

Ammonium acetate buffer mixture: mix 460 cm2 mol/DMacetic acid and 540 cm2 mol/DMammonia solution. the pH of the mixture to 7.7. PH control a pH meter. If the pH of the mixture is greater than or less than the specified, it is set to the right by adding 2 mol/DMacetic acid or ammonia.

Ascorbic acid, freshly prepared solution with a mass fraction of 5%.

Eryhromycin , a solution with a mass fraction of 0.07%: 0.7 g of erioglaucine dissolved in 2 cmof nitric acid with stirring, and after 2 minutes add 70 cmof water, 0.3 g of urea was stirred and kept for 24 h in a dark place. The solution was then filtered into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix. The solution was stored in a flask made of dark glass.

Urea.

Aluminium metal according to GOST 11069*.
________________
* On the territory of the Russian Federation GOST 11069−2001. Here and further. — Note the manufacturer’s database.

Solutions of the aluminium standard.

Solution a (spare): 0,1000 g of aluminium is dissolved in 20 cmof hydrochloric acid diluted 1:1. The resulting solution was transferred to a volumetric flask with a capacity of 1 DM, adjusted to the mark with water, mix.

1 cmof the solution contains 1·10g of aluminum.

Solution B is prepared on the day of application: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof a solution contains 1·10g of aluminum.

(Modified re

Doccia, Rev. N 2, 3).

2.3. Analysis

2.3.1. A portion of tin weighing 1 g is placed in a beaker with a capacity of 250 cm, 10 cm, pour themixture to dissolve, cover with a watch glass and leave you without heating to dissolve the sample. After dissolution of tin in the glass is washed with 3 cmof hydrochloric acid and evaporated to dryness at a temperature of 80−90 °C. To the cooled residue poured 5 cmof the mixture and evaporated again to dryness. Treatment 5 cmof the mixture to dissolve is repeated until the complete removal of the tin. To the dry salts poured 3 cmof hydrochloric acid, a few drops of hydrogen peroxide and evaporated to dryness. If after treatment with the acids hydrochloric acid solution has a brown color, then a treatment with hydrochloric acid and hydrogen peroxide again.

The dry residue was dissolved in 1 cmof a solution of hydrochloric acid 7 mol/DM. When the content of aluminum up to 0.005% in the future use the entire solution. The solution was transferred to a volumetric flask with a capacity of 100 cmusing 10 cmof water. When the mass fraction of aluminum of 0.005% hydrochloric acid solution is transferred to a volumetric flask with a capacity of 100 cm, flow 10 cmof hydrochloric acid 7 mol/l, adjusted to the mark with water and mix. In a volumetric flask with a capacity of 100 cmdepending on the mass fraction of aluminum taken aliquot part of the solution of sample, is given in table.1A. When selecting aliquote parts of a solution with a volume of 5 cmto it add 5 cmof water and 0.5 cmof a solution of hydrochloric acid 7 mol/DM.

Table 1A

To the entire solution or to aliquote part of the solution add 30 cmof ammonium-acetate buffer solution, 2 cmof ascorbic acid solution and 10 cmof a solution of erioglaucine , stirring the solution after each addition of the reagent. The solution was adjusted with ammonium acetate buffer solution to the mark and mix. The pH of the solution is checked for pH meter and should be of 6.2−6.5. If necessary, the pH is adjusted to the desired value by dropwise addition of aqueous ammonia or acetic acid.

After 10 minutes measure the optical density of the solution on the spectrophotometer at a wavelength of 530 nm or photoelectrocolorimeter using the filter with the scope light transmission ranges from 520 to 540 nm and cuvettes with an optimum thickness of the layer. As a solution comparison solution is used in the reference experiment.

A lot of aluminium in the solution found by the calibration schedule.

(Changed edition, Rev. N 1, 2, 3).

2.3.2. To build a calibration curve in seven volumetric flasks with a capacity of 100 cmmake a 10 cmwater, 1 cmof a solution of hydrochloric acid 7 mol/DM, 30 cmammonium acetate buffer solution and 2 cmof a solution of ascorbic acid. Then six of them poured 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution B, which corresponds to 0,005; 0,01; 0,02; 0,03; 0,04 and 0.05 mg of aluminium and stirred. All flasks is poured 10 cmof a solution of erioglaucine , bring to mark ammonium acetate buffer solution, stirred and analysis are as indicated in claim 2.3.1.

By readings of optical density and known concentration of aluminium in the solutions to build the calibration graph.

(Changed edition, Rev. N

2).

2.4. Processing of the results

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

,

where is the mass of aluminum was found in the calibration schedule g;

 — weight of tin,

2.4.2. Allowable absolute discrepancies in the results of parallel measurements at a confidence probability of 0.95 should not exceed the values given in table.1.

Table 1

(Changed edition, Rev. N 2).

3. PHOTOMETRIC METHOD FOR DETERMINATION OF ALUMINUM WITH ALUMININUM

3.1. The essence of the method

The method is based on fotomaterialy complex compound of aluminum with alumininum. Tin and antimony is distilled off in the form of bromides, lead is separated in the form of a compound with thioglycolic acid.

3.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

pH meter laboratory.

Hydrochloric acid of high purity according to GOST 14261 and diluted 1:1.

Bromatologia acid according to GOST 2062.

Bromine according to GOST 4109.

Mix to dissolve: to 25 cmof hydrochloric acid poured 25 cmbromatological acid and 15 cmof bromine.

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

Hydrogen peroxide according to GOST 10929.

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

Thioglycolic acid, a solution with a mass fraction of 1%: 2 cmof a solution of thioglycolic acid with a mass fraction of 95% was placed in a volumetric flask with a capacity of 200 cm, adjusted to the mark with water and mix.

Ascorbic acid, freshly prepared solution with a mass fraction of 5%.

A mixture of thioglycolic and ascorbic acids; are prepared the day of application: mix 200 cmof the solution of thioglycolic acid with a mass fraction of 1%, and 100 cmof the ascorbic acid solution with a mass fraction of 5%.

Thiourea according to GOST 6344, solution with a mass fraction of 10%.

Acetic acid according to GOST 61.

Ammonium acetate according to GOST 3117.

Buffer solution with pH 5.5: 125 g ammonium acetate are dissolved in 250 cmof water, add 20 cmof glacial acetic acid, stirred, transferred to a volumetric flask with a capacity of 1 DM, adjusted to the mark with water and mix.

Aluminon (ammonium salt aurintricarboxylic acid) for NTD, a solution with a mass fraction of 0.1%. Prepared the day before use.

Aluminium metal according to GOST 11069.

Solutions of the aluminium standard.

Solution a (spare): 0,1000 g of aluminium is dissolved in 10 cmof hydrochloric acid diluted 1:1. The resulting solution was transferred to a volumetric flask with a capacity of 1 DM, adjusted to the mark with water and mix.

1 cmof the solution contains 1·10g of aluminum.

Solution B is prepared on the day of application: 10,0 smsolution And transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof a solution contains 1·10g of aluminum.

(Amended And

ZM. N 1, 3).

3.3. Analysis

3.3.1. A portion of tin weighing 1 g is placed in a beaker with a capacity of 100 cm, 10 cm, pour themixture to dissolve, cover with a watch glass and leave you without heating to dissolve the sample. After dissolution of tin in the glass is washed with 3 cmof hydrochloric acid and evaporated to dryness at a temperature of 80−90 °C. To the cooled residue poured 5 cmof the mixture and evaporated again to dryness. Treatment 5 cmof the mixture of acids with bromine is repeated until the complete removal of the tin. To the dry salts poured 3 cmof hydrochloric acid, a few drops of hydrogen peroxide and evaporated to dryness. If after treatment with the acids hydrochloric acid solution has a brown color, then a treatment with hydrochloric acid and hydrogen peroxide again.

The residue is moistened with 1 cmof nitric acid, diluted 1:2, pour 30 cmof water, 3.0 cmof a mixture of thioglycolic and ascorbic acid, 2.0 cmof a solution of thiourea, mixing after addition of each reagent.

If a white precipitate of lead compounds with thioglycolic acid fell, it was filtered through a pad of filtrowanie mass and washed 2−3 times with water.

Set the solution pH 4,7−5,0 (using pH meter) using ammonia solution, diluted 1:1 nitric acid diluted 1:2. Then pour 15 cmbuffer solution, 20 mmsolution of aluminon. After 10 minutes transfer the solution into a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

After 20 minutes, measure the optical density of the solution on the spectrophotometer at a wavelength of 520 nm or photoelectrocolorimeter using a filter with a field transmission 510−530 nm and cuvettes with an optimum thickness of the layer.

As a solution comparison, using a zero solution (see p.3.3.2).

From the readings of the optical density of the analyzed solution subtract the readings of the optical density of control experiment through all stages of the analysis.

The amount of aluminium in the solution found by the calibration schedule.

(Changed edition, Rev. N

1, 3).

3.3.2. To build a calibration curve in a volumetric flask with a capacity of 100 cmmeasure off microburette 0; 0,3; 0,6; 1,0; 1,5; 2,0; 2,5 and 3.0 cmstandard solution B, and poured 1 cmof nitric acid, diluted 1:2, 30 cmof water and then do as in point 3.3.1.

As a solution comparison, using a zero solution.

By readings of optical density and known concentration of aluminium in the solutions to build the calibration graph.

3.4. Processing of the results

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

,

where is the mass of aluminum was found in the calibration schedule g;

 — weight of tin,

3.4.2. Allowable absolute discrepancies in the results of parallel measurements at a confidence probability of 0.95 should not exceed the values given in table.2.

Table 2