GOST 12697.1-77
GOST 12697.1−77 Aluminum. Methods for the determination of vanadium (with Amendments No. 1, 2, 3)
GOST 12697.1−77
Group B59
INTERSTATE STANDARD
ALUMINIUM
Methods for determination of vanadium
Methods for determination of vanadium*
________________
* In the original paper in the name of the standard is missing the word «Aluminium». — Note the manufacturer’s database.
ISS 77.120.10
AXTU 1709
Date of introduction 1979−01−01
The decision of the State standards Committee of the Council of Ministers of the USSR from
Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
REPLACE GOST 12697−67 in part of sec. 2
EDITION with Amendments No. 1, 2, 3, approved in November 1981, November 1985, may 1988 (ICS 1−82, 2−86, 8−88).
This standard establishes photometric methods for determination of vanadium in aluminium:
method with the use of N-benzoyl-N'-phenylhydroxylamine (if mass fraction of vanadium from 0.0005 to 0.01%);
— method with the use of phosphorus-tungsten acid (with mass fraction of vanadium from 0.002 to 0.03%).
(Changed edition, Rev. N 1, 3).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 25086−87.
(Changed edition, Rev. N 2).
1.2. For the analysis of high-purity aluminium grades A995 and the A99 sample of aluminium manufacture in the form of rods of size mm and 5х20х130 in the form of rods with dimensions 
In the upper part of the rod sharpened on the size of the sample holder (see drawing).
1.3. Mass fraction of components in aluminium is determined in three batches.
1.4. Determination of the mass fraction of components in aluminium of high purity should be performed in two series of two parallel batches in each series. The result of the analysis taking the arithmetic mean of the results of the two series.
1.2−1.4. (Changed edition, Rev. N 2, 3).
1.5. Allowed the use of other equipment, materials and reagents, subject to obtaining the metrological characteristics are not inferior to the specified in the standard methods of analysis.
1.6. Allowed to use other methods, certified according to GOST 8.010−90* if their metrological characteristics are not inferior to the characteristics of methods included in these standards.
________________
* On the territory of the Russian Federation GOST R 8.563−96**.
** On the territory of the Russian Federation GOST R 8.563−2009. — Note the manufacturer’s database.
1.7. The numerical value of the result of the analysis must end with a digit of the same rank as that of the normalized indicator grade composition.
1.8. For the analysis of high-purity aluminium is used in dishes made of quartz glass according to GOST 19908−90.
1.9. After the warranty term of the reagents allowed to check the shelf life of the reagents by analysing standard samples of aluminum at least once per quarter.
1.5−1.9. (Added, Rev. N 3).
A. Photometric method for the determination of vanadium with N-benzoyl-N'-phenylhydroxylamine
The method is based on the formation in sulfuric acid solution of 2.25 mol/DMpainted in purple color complex compounds of pentavalent vanadium with N-benzoyl-N'-phenylhydroxylamine. This compound is extracted with chloroform after creating the acidity of the solution 3.5 mol/l
by hydrochloric acid.
The influence of titanium can be eliminated by addition of sodium fluoride.
Colored solution photometered in 
(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** (here and below).
** On the territory of the Russian Federation GOST R 53228−2008, here and hereafter. — Note the manufacturer’s database.
Sulfuric acid GOST 4204−77, diluted 1:1 and a solution of 4 mol/DM.
Hydrochloric acid by the GOST 3118−77.
Sodium hydroxide according to GOST 4328−77, solutions with a mass fraction of 5% and 20%. Store in a plastic container.
Chloroform (trichlormethane) according to GOST 20015−88.
N-benzoyl-N'-phenylhydroxylamine (N-phenylbenzimidazole acid), a solution with a mass fraction of 0,1% in chloroform.
Potassium permanganate according to GOST 20490−75, a solution with a mass fraction of 0.6%.
Sodium fluoride according to GOST 4463−76.
Of vanadium pentoxide.
Solutions of vanadium standard.
Nitric acid GOST 4461−77 diluted 1:1.
Vanadium metal.
Sodium sulphate anhydrous according to GOST 4166−76.
Solution A, prepared as follows: 0,1785 g of vanadium pentoxide, previously dried at 250 °C and cooled in a desiccator, are dissolved in 8 cmof sodium hydroxide solution 50 g/DM
, then the solution was acidified by 10 cm
of sulphuric acid diluted 1:1, poured in a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and stirred or 0,1000 g of vanadium dissolved in 20 cm
of nitric acid, diluted 1:1. After dissolution the solution was transferred into 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 vanadium (V).
Solution B is prepared as follows: a pipette, take 25 cmof solution A in a volumetric flask with a capacity of 500 cm
, made up to the mark with water and mix. The solution is prepared before use.
1 cmof a solution contains 0.005 mg of vanadium (V).
(Changed edition, Rev. N 1, 3).
3. ANALYSIS
3.1. Weighed aluminium weighing 2 g were placed in a glass with a capacity of 400 cmor Nickel Cup with lid with a capacity of 250 cm
, flow 50 cm
of a solution of sodium hydroxide 200 g/DM
is served in a glass watch glass. After the violent reaction is washed with glass and walls of beaker with water and heated to dissolve sample. The cooled solution was poured 50 cm
of water, and then a solution of 4 mol/DM
sulfuric acid in an amount necessary for translation 2 g of aluminum sulfate (27.8 cm
) and to neutralize the sodium hydroxide. The acid consumption for neutralization of sodium hydroxide establish a titration of sodium hydroxide solution of 4 mol/DM
sulphuric acid in presence of methyl orange.
Sulfuric acid should be added carefully, to avoid splashing of the solution. The solution is heated to dissolve the salt, cooled, transferred to a volumetric flask with a capacity of 200 cmand dilute to the mark with water.
Pipetted 25−50 cmof solution, depending on the assumed mass fraction of vanadium in a separating funnel with a capacity of 200 cm
. Dilute with water to 50 cm
. Pour the 17.5 cm
of sulphuric acid diluted 1:1, the vanadium is oxidized to pentavalent, adding dropwise a solution of potassium permanganate until a stable pink color. After 5 min in a separating funnel add 10 cm
of a solution of N-benzoyl-N'-phenylhydroxylamine, then 32 cm
of hydrochloric acid. Hydrochloric acid is added immediately before extraction of the colored complex. The solution was shaken for 1 min and after phase separation the chloroform phase was transferred to a dry volumetric flask with a capacity of 50 cm
, avoiding contact with the aqueous phase.
The extraction was repeated with 10 cmof chloroform, the chloroform phase merging into the same volumetric flask. Extract in a volumetric flask top up to the mark with chloroform and mix. In a volumetric flask to obtain a clear solution, you can add 1 g of sodium sulfate and shake.
If the sample mass fraction of titanium is more mass fraction of vanadium in 10 times, which is noticeable by the brown coloration of the chloroform extracts, before oxidation of vanadium by the potassium permanganate was added 0.3 g of sodium fluoride.
Optical density of the solution is measured on a photoelectrocolorimeter or spectrophotometer, given that a maximum of light absorption of solutions corresponds to a wavelength of 385 nm.
Solution comparison is the chloroform.
At the same time spend control experience. To do this in a volumetric flask with a capacity of 200 cmis placed a solution of 4 mol/DM
sulfuric acid in an amount of 27.8 cm
is less than for the test solution, carefully pour 50 cm
of sodium hydroxide solution 200 g/DM
, made up to the mark with water and mix. Select aliquot part of the solution corresponding to aliquote part of the test solution in a separating funnel with a capacity of 200 cm
and the analysis is carried out as described above.
The weight of the vanadium is determined according to the calibration schedule, taking into account the amendment in the reference experiment.
(Modified redakts
ia, Rev. N 1, 3).
3.2. Construction of calibration curve
In a separating funnel with a capacity of 200 cmfrom microburette poured 0, 1, 2, 4, 6, 8, 10 cm
standard solution B, which corresponds to 0; 0,005; 0,010; 0,020; 0,030; 0,040; 0,050 mg of vanadium.
To each separating funnel pour the 17.5 cmof sulphuric acid diluted 1:1, add water up to 70 cm
and further analysis is carried out as specified in clause 3.1.
Solution comparison is the solution, in which vanadium is not added. According to the obtained values of optical density of the solutions and the known mass of vanadium build the calibration graph.
(Changed edition, Rev. N 3).
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of vanadium () in percent is calculated by the formula
where — weight of vanadium was found in the calibration graphics mg;
— the total volume of solution, cm
;
— volume aliquote part of the solution, cm
;
the weight of aluminium,
4.2. Permissible discrepancies in the results of parallel definitions should not exceed the values given in table.1.
Table 1
| Mass fraction of vanadium, % |
Allowable difference, % | |
| convergence Rel. |
reproducibility, Rel. | |
| From 0.0005 to 0.003 incl. |
30 |
45 |
| SV. Of 0.003 «to 0.01 « |
20 |
30 |
(Changed edition, Rev. N 1, 3).
B. Photometric method for the determination of vanadium with phosphorus-tungsten acid
The method is based on formation of yellow complex compounds with phosphorus-tungsten acid. Colored solution photometered in 
(Changed edition, Rev. N 3).
5. 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 of the 2nd accuracy class with the weighing error of 0.0002 g.
Nitric acid GOST 4461−77 and diluted 1:1.
Orthophosphoric acid according to GOST 6552−80.
Sodium hydroxide according to GOST 4328−77, a solution with a mass fraction of 25%.
Sodium volframovich according to GOST 18289−78, a solution of 0.5 mol/DM.
Of vanadium pentoxide.
Vanadium metal.
Solutions of vanadium standard.
Solution A; 0,1785 g of vanadium pentoxide, previously dried at 250 °C and cooled in a desiccator, dissolved in a mixture of 50 cmof water and 10 cm
of sodium hydroxide solution, acidified by 20 cm
of concentrated nitric acid, then the solution was transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and stirred; or 0,1000 g of vanadium dissolved in 20 cm
of nitric acid, diluted 1:1. After dissolution is 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 vanadium.
Solution B; pipette take 10 cmof solution A in a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix. The solution is prepared before use.
1 cmof a solution contains 0.01 mg of vanadium.
Sec. 5. (Changed edition, Rev. N 3).
6. ANALYSIS
6.1. 1 g of the sample when the mass fraction of vanadium to 0.015% or 0.5 g when the mass fraction of vanadium of more than 0,015% dissolved in 10 cmof sodium hydroxide in a Nickel Cup with lid with a capacity of 250 cm
, or in a glass with a capacity of 400 cm
, covering a glass watch glass.
After dissolution acidified by 20 cmof nitric acid and boiled until the enlightenment. The solution is diluted with hot water to a volume of approximately 40 cm
, add 1.0 cm
of phosphoric acid and 1.5 cm
mortar volframovich sodium and stirred. The solution was cooled, transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix. After 30 min, measure the optical density of the solution on the photoelectrocolorimeter or spectrophotometer, given that a maximum of light absorption of solutions corresponds to 430 nm.
Solution comparison is water. At the same time spend control experience.
The weight of the vanadium is determined according to the calibration schedule, taking into account the amendment in the reference experiment.
(Changed edition, Rev. N 3
).
6.2. Construction of calibration curve
Six glasses with a capacity of 250 cmfrom burette poured 0; 2; 5; 8; 10 and 15 cm
standard solution B, that corresponds to the content 0; 0,02; 0,05; 0,08; 0,10 and 0,15 mg of vanadium.
The solution is diluted with hot water to a volume of approximately 40 cm, and further analysis is carried out as specified in clause
Solution comparison is the solution, in which vanadium is not added. According to the obtained values of optical density of the solutions and the known mass of vanadium build the calibration graph.
(Changed edition, Rev. N 3).
7. PROCESSING OF THE RESULTS
7.1. Mass fraction of vanadium () in percent is calculated by the formula
where — weight of vanadium was found in the calibration graphics mg;
the weight of aluminium,
(Added, Rev. N 1).
7.2. Permissible discrepancies in the results of parallel definitions should not exceed the values given in table.2.
Table 2
| Mass fraction of vanadium, % |
Allowable difference, % | |
| convergence Rel. |
reproducibility, Rel. | |
| From 0.002 to 0.01 incl. |
20 |
30 |
| SV. Is 0.01 «to 0.03 « |
10 |
15 |
(Changed edition, Rev. N 1, 3).
