GOST 12697.3-77
GOST 12697.3−77 Aluminum. Methods for determination of manganese (with Amendments No. 1, 2, 3, 4, as amended)
GOST 12697.3−77
Group B59
INTERSTATE STANDARD
ALUMINIUM
Methods for determination of manganese
Aluminium. Methods for determination of manganese
ISS 77.120.10
AXTU 1709
Date of introduction 1979−01−01
Resolution of the USSR State Committee for standards from
Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
REPLACE GOST 12699−67 in part of sec. 2
EDITION with Amendments No. 1, 2, 3, 4, approved in November 1981, November 1985, may 1987, may 1988 (ICS 1−82, 2−86, 8−87, 8−88).
AMENDED, published in IMS No. 1, 2005
An amendment made by the manufacturer of the database
This standard specifies methods for the determination of manganese in aluminum: photometric at a mass fraction of from 0.001 to 0.015% and the atomic absorption when the mass fraction of from 0.005 to 0.015%.
(Changed edition, Rev. N 3, 4).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 12697.1−77 and GOST 25086−87.
(Changed edition, Rev. N 4).
A. Photometric method
The essence of the method consists in the oxidation of manganese in acidic medium to pneumococcal condition with periodate potassium or sodium and fotomaterialy coloring manganese acid at 
(Changed edition, Rev. N 3).
2. APPARATUS, REAGENTS AND SOLUTIONS
Types photoelectrocolorimeter FEK-56M, PEC-60, KLF or the types of spectrophotometer SF-16, SF-26, or similar type.
Laboratory scales according to GOST 24104−88* 2nd accuracy class with the weighing error of 0.0002 g.
________________
* From 1 July 2002 was put into effect GOST 24104−2001**.
** On the territory of the Russian Federation GOST R 53228−2008. — Note the manufacturer’s database.
Sulfuric acid GOST 4204−77 and diluted 1:1.
Nitric acid GOST 4461−77.
Orthophosphoric acid according to GOST 6552−80, diluted 1:1.
Hydrogen peroxide according to GOST 10929−76.
Sodium hydroxide according to GOST 4328−77, a solution with a mass fraction of 20% stored in a plastic container.
A mixture of acids, is prepared as follows: 525 cmof water is poured under stirring with 100 cm
of concentrated sulfuric acid and 250 cm.
of concentrated nitric acid.
Potassium ignominy (periodic) or sodium cognately, a freshly prepared solution with a mass fraction of 5%.
5 g of periodate potassium or sodium dissolve in water when heated, add 20 cmof nitric acid and the volume was adjusted with water to 100 cm
.
Water reducing agents; prepared as follows: to 1000 cmof distilled water add 5 cm
of sulphuric acid diluted 1:1, heated to boiling, add a few crystals jednolitego potassium or sodium and boiled for 10 min.
Potassium permanganate according to GOST 20490−75.
Solutions of manganese standard.
Sodium sanitarily.
Sodium atomistically according to GOST 4197−74, a solution of 20 g/DM.
Manganese metal is cleaned in the following manner: a few grams of metal was placed in a beaker with a capacity of 250 cm, add about 80 cm
of sulphuric acid diluted 1:1, and 100 cm
of water, stirred and after a few minutes, poured the solution.
The metal was washed two times with water, then with acetone, dried in a drying Cabinet at 100 °C for 2 min and cooled in a desiccator.
Solution A, prepared as follows: 0,2877 g of potassium permanganate dissolved in water, add 20 cmof sulphuric acid diluted 1:1, heat, add dropwise a hydrogen peroxide solution or a few crystals of sodium semitecolo to bleaching and the solution is evaporated to release vapors of sulfuric acid. The residue after cooling was dissolved in water and transferred the solution into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and stirred or 0,1000 g of manganese dissolved in a beaker with a capacity of 600 cm
under the watch glass 20 cm
of concentrated sulfuric acid, adding 100 cm
of water. The solution was boiled a few minutes, cooled, transferred to a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and mix.
1 cmof solution A contains 0.1 mg of manganese (Mn).
Solution B is prepared before use as follows: pipetted 50 cmof solution A in a volumetric flask with a capacity of 500 cm
, made up to the mark with water and mix.
1 cmof a solution contains 0.01 mg of manganese (Mn).
Manganese metal in the form of chips.
Acetone according to GOST 2603−79.
(Changed edition, Rev. N 1, 3, 4).
3. ANALYSIS
3.1. Weighed aluminium weighing 1 g is placed in a conical flask with a capacity of 250 cmand poured 20 cm
of the sodium hydroxide solution. After the violent reaction is washed with the walls of the flask with water and heated to dissolve sample. The cooled solution was added 30 cm
of water, and while stirring, pour the 40 cm
of a mixture of acids. The walls of the flask is washed with water and heated until complete dissolution of aluminium hydroxide and produce a clear solution. To the hot solution pour 3 cm
of phosphoric acid, heated to boiling, and add 10 cm
of periodate solution of potassium or sodium, boil for 5 minutes until the appearance of pink color, then allowed to stand 30 min at a temperature close to the boiling point, maintaining the solution volume of about 50 cm
.
Colored solution is transferred to a volumetric flask with a capacity of 50 cm, pre-washed with water containing no reducing agents, and dilute to the mark with the same water. Solution comparison is water. The optical density of test solution is measured on a photoelectrocolorimeter or spectrophotometer, given that a maximum of light absorption of solutions corresponds to the wavelength of 528 nm. In the presence of colored ions after measuring the optical density of the solution of manganous acid destroy two drops of a solution of sodium attestatio and repeat the measurement of optical density. The difference between the two obtained values corresponds to the optical density of the actual mass of manganese in the sample.
At the same time conducting follow experience for this 15 cmof the mixture of acids was evaporated to dryness. To the residue poured a small amount of hot water, 25 cm
of a mixture of acids and heat. Then poured 20 cm
of the sodium hydroxide solution, 3 cm in
phosphoric acid and analyze as described above.
The mass of manganese is determined according to the calibration schedule, taking into account the amendment in the reference experiment.
(Changed edition, Rev. N 1,
3, 4).
3.2. Construction of calibration curve
In a conical flask with a capacity of 250 cmpoured from microburette 0; 1; 2; 4; 6; 8; 10; 12; 15 and 18 cm
of solution B, which corresponds to 0; 0,01; 0,02; 0,04; 0,06; 0,08; 0,10; 0,12; 0,15 and 0.18 mg of manganese. To each flask add 20 cm
of a mixture of acids, 3 cm
of phosphoric acid and then act as described in section 3.1. Solution comparison is the solution, in which manganese was not added.
According to the obtained values of optical density of solutions and the known masses of manganese build the calibration graph.
(Changed edition, Rev. N 1, 4).
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of manganese () in percent is calculated by the formula
where is the mass of manganese in the sample solution found by the calibration schedule, mg;
— the mass of manganese in solution in the reference experiment, was found in graduirovannam graphics mg;
— the weight of the portion,
(Changed edition, Rev. N 3).
4.2. Permissible discrepancies in the results of parallel definitions should not exceed the values given in the table.
| Mass fraction of manganese, % |
Allowable difference, % | |
| convergence Rel. |
reproducibility, Rel. | |
| From 0.001 to 0.003 incl. |
30 |
45 |
| SV. Of 0.003 «to 0.008 « |
20 |
30 |
| «0,008» 0,0015 « |
15 |
25 |
(Changed edition, Rev. N 3, 4).
B. Atomic absorption method
The essence of the method consists in dissolving the sample of aluminium in hydrochloric acid in the presence of hydrogen peroxide and subsequent measurement of the atomic absorption of manganese at a wavelength of 279.5 nm in the flame acetylene-air.
5. APPARATUS, REAGENTS AND SOLUTIONS
Atomic absorption spectrophotometer with all accessories and with a radiation source for manganese.
Acetylene in cylinders for technical GOST 5457−75.
Hydrochloric acid by the GOST 3118−77, diluted 1:1.
Sulfuric acid GOST 4204−77, diluted 1:1.
Sodium sanitarily by ND.
Hydrogen peroxide according to GOST 10929−76.
Acetone according to GOST 2603−79.
Nickel dichloride (NiCl· 6H
O) according to GOST 4038−79, a solution of 2 g/DM
.
Aluminium in the form of chips with a mass fraction of manganese is not more than 0.001%. If necessary, shaving before use, washed with acetone, dried in a drying Cabinet at 100 °C for 2−3 min and cooled in a desiccator.
A solution of aluminum 20 g/DM: 10 g of aluminum is placed in a beaker with a capacity of 600 cm
, 300 cm poured
hydrochloric acid solution and dissolved by heating, adding 1 cm
of a solution of Nickel dichloride. The solution was cooled, transferred to a volumetric flask with a capacity of 500 cm
; refill to the mark with water and mix.
Manganese metal in the form of chips.
If the metal surface is covered with an oxide film, it is cleaned as specified in sec. 2.
Potassium permanganate according to GOST 20490−75.
Standard solutions of manganese.
Solution a — sec. 2.
Solution B: 250 cmsolution And transferred to a volumetric flask with a capacity of 500 cm
, made up to the mark with water and mix. Prepared before use.
1 cmof the solution contains 0.05 mg of manganese.
6. ANALYSIS
6.1. A portion of the sample weighing 1.0 g was placed in a beaker with a capacity of 250 cm, 30 cm, pour the
hydrochloric acid solution, if necessary, to accelerate the dissolution add 0.5 cm
of a solution of Nickel dichloride. Beaker cover watch glass. After the cessation of violent reaction solution is gently warmed and a few drops of hydrogen peroxide solution. After dissolution, the excess hydrogen peroxide is removed by boiling, watch glass and walls of beaker rinse with hot water.
The resulting solution, if necessary, is evaporated, cooled, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.
The solution in the reference experiment is prepared according to claim 6.1, using is sample the sample the sample of aluminium with a manganese content not more than 0.001%.
Measure the atomic absorption of manganese in the sample solution, control solution and experience in solutions for constructing the calibration curve at a wavelength of 279.5 nm in the flame acetylene-air. The concentration of manganese in the sample solution and in the solution of control and experience determined by the calibration schedule.
6.2. To build a calibration curve in five volumetric flasks with a capacity of 100 cmmeasure 50 cm
of the solution is aluminum, then the four of them poured 1,0; 2,0; 3,0; 4,0 cm
standard solution B, which corresponds to 0,05, 0,10, 0,15, 0,20 mg of manganese.
The solutions in flasks topped up to the mark with water, mix and measure the atomic absorption of manganese, as specified in clause 6.1.
From the obtained values of atomic absorption solutions containing a standard solution, subtract the value of atomic absorption of a solution containing a standard solution, and the obtained values of atomic absorption and corresponding masses of manganese build the calibration graph.
7. PROCESSING OF THE RESULTS
7.1. Mass fraction of manganese () in percent is calculated by the formula
where is the mass of manganese in the sample solution found by the calibration schedule, mg;
— the mass of manganese in solution in the reference experiment, was found in the calibration graphics mg;
— the weight of the portion of the sample,
7.2. Discrepancies in the results of parallel definitions should not exceed the values given in the table.
Sec. B. (Added, Rev. N 3).
