GOST 12645.6-77
GOST 12645.6−77 indium. Methods for determination of iron (with Amendments No. 1, 2, 3)
GOST 12645.6−77
Group B59
STATE STANDARD OF THE USSR
INDIUM
Methods of iron determination
Indium. Methods for determination of iron
AXTU 1709
Date of introduction 1978−07−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
A. P. Sychev, L. K. Larina (supervisor), M. G. Saun (supervisor), V. N. Makarceva, N. With. References: E. V. Lisitsyn, N. Romanenko, V. A. Kolesnikov
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
Change No. 3 adopted by the Interstate Council for standardization, Metrology and certification
The adoption voted:
The name of the state |
The name of the national authority for standardization |
The Republic Of Azerbaijan |
Azgosstandart |
The Republic Of Belarus |
Gosstandart Of Belarus |
The Republic Of Kazakhstan |
Gosstandart Of The Republic Of Kazakhstan |
The Republic Of Moldova |
Moldovastandart |
Russian Federation |
Gosstandart Of Russia |
Turkmenistan |
The main state inspection of Turkmenistan |
The Republic Of Uzbekistan |
Standards |
Ukraine |
Gosstandart Of Ukraine |
3. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
The designation of the reference document referenced |
The number of the paragraph, subparagraph |
GOST 2603−79 |
3.2 |
GOST 4461−77 |
3.2 |
GOST 5830−79 |
2.2 |
GOST 6709−72 |
2.2, 3.2 |
GOST 9849−86 |
2.2, 3.2 |
GOST 10929−76 |
2.2, 3.2 |
GOST 11125−84 |
2.2, 3.2 |
GOST 12645.0−83 |
1.1 |
GOST 14261−77 |
2.2, 3.2 |
GOST 19908−90 |
2.2 |
GOST 22306−77 |
1.1 |
GOST 27067−86 |
2.2, 3.2 |
4. Limitation of actions taken on the Protocol 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
5. REVISED (March 1998) with Amendments No. 1, 2, 3, approved in February 1983, December 1987-June 1996 (IUS 5−83, 3−88, 9−96)
This standard specifies a visual colorimetric method for determination of iron in India, when the mass fraction of iron from 1·10to 1·10and photocolorimetric method for the determination of iron in iron mass fraction of from 1·10to 8·10%.
(Changed edition, Rev. N 1, 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis and security requirements — according to GOST and GOST 12645.0 22306.
(Changed edition, Rev. N 2).
2. VISUAL COLORIMETRIC METHOD FOR THE DETERMINATION OF IRON CONTENT IN INDIA
2.1. The essence of the method
The method is based on the ability of ferric iron ions to form a thiocyanate complex compound of the red color intensity in the organic layer compared with the scale of comparison.
2.2. Apparatus, reagents and solutions
Quartz ware according to GOST 19908.
Cylinders for photometry with a glass stopper with a height of 18 cm and a diameter of 1 cm.
Hydrochloric acid of high purity according to GOST 14261, diluted 1:1.
Hydrogen peroxide according to GOST 10929, a solution of 30 g/DM.
Nitric acid of high purity according to GOST 11125, diluted 1:1 and 1:9, boiled to remove oxides of nitrogen.
Ammonium radamisty according to GOST 27067, a solution of 500 g/DM.
Isoamyl alcohol according to GOST 5830.
Standard solutions of iron.
Solution a: 0,100 g of iron powder was dissolved in 5 cmof nitric acid, diluted 1:1, add 25 cmof water and heated to boiling. The solution was cooled, transferred to a volumetric flask with a capacity of 1 DMand adjusted to the mark with nitric acid, diluted 1:9.
1 cmof solution A contains 0.1 mg of iron.
Solution B: 2 cmof solution A is placed in a volumetric flask with a capacity of 1 DMand bring to mark with water.
1 cmof solution B contains 0.2 mcg of iron.
Solution B is prepared on the day of application.
Distilled water according to GOST 6709, double-distilled in quartz apparatus.
Iron powder restored brand MLB-1 according to GOST 9849.
(Changed edition, Rev. N 2,
3).
2.3. Analysis
2.3.1. The weight India weight of 1,000 g was placed in a quartz flask with a capacity of 100 cm, dissolved under moderate heating of the tiles is covered with a quartz cover, 5 cmof hydrochloric acid diluted 1:1, add two drops of solution of hydrogen peroxide, 5 cmof water and boil until the destruction of hydrogen peroxide.
Transfer the solution into the cylinder with a glass stopper with a height of 18 cm and a diameter of 1 cm, washed the walls of the flask with water and the volume was adjusted to 10 cm.
Pour 1 cmof nitric acid, diluted 1:9, 2 cmof mortar Rodenstock ammonium, 2 cmisoamyl alcohol, close the cylinder tube and shake for 10 seconds.
The color in the organic layer compared (side) scale comparison.
Simultaneously conduct control experience, and hydrochloric acid, which in the sample is consumed in the decomposition of the sample, a control experiment was evaporated to dryness and lead further analysis as described above.
(Changed edition, Rev. N 1, 2, 3)
.
2.3.2. Preparation of the scale comparison
In the cylinder with a glass stopper with a height of 18 cm and a diameter of 1 cm is introduced from 0.5 to 3.5 cmwith an interval of 0.5 cmstandard solution B, which corresponds to iron content from 0.1 to 0.7 micrograms at intervals of 0.1 µg.
Then pour up to 10 cmwater, 1 cmof nitric acid, diluted 1:9, 2 cmof mortar Rodenstock ammonium, 2 cmisoamyl alcohol and shake for 10 seconds.
The scale is prepared simultaneously with the samples. Scale is sustainable for 20−30 min.
(Changed edition, Rev. N 2).
2.4. Processing of the results
2.4.1. Mass fraction of iron () in percent is calculated by the formula
,
— the amount of iron taken in the sample, µg;
— the amount of iron in solution in the reference experiment, µg;
— the weight of the portion India,
2.4.2. For the results analysis be the arithmetic mean of three parallel measurements.
The difference between the largest and smallest of the three results of parallel measurements with a confidence probability of 0.95 should not exceed the values of permissible differences of the three results of parallel measurements calculated by the formulae:
for the mass fraction of iron from 1·10to 5·10%;
for the mass fraction of iron from 5·10to 1·10%,
where is the arithmetic mean of results of three parallel measurements.
The difference between the smaller and larger of the two results of the analysis of the same samples with a confidence level of 0.95, should not exceed the values of permissible differences of the two analysis results calculated by the formulae:
for the mass fraction of iron from 1·10to 5·10%;
for the mass fraction of iron from 5·10to 1·10%,
where — the average of the two matched analyses.
(Changed edition, Rev. N 2).
3. PHOTOCOLORIMETRIC METHOD FOR DETERMINATION OF IRON CONTENT
3.1. The essence of the method
The method is based on the ability of ferric iron ions to form a complex compound with thiocyanate and measuring the optical density of the colored complex in the region of wavelengths of 500−520 nm.
3.2. Apparatus, reagents and solutions
Photoelectrocolorimeter.
Hydrochloric acid according to GOST 14261, diluted 1:1.
Hydrogen peroxide according to GOST 10929.
Acetone according to GOST 2603.
Nitric acid according to GOST 11125 diluted 1:9, boiled to remove oxides of nitrogen.
Ammonium radamisty according to GOST 27067, a solution of 500 g/DM.
Standard solutions of iron.
Solution A, prepared as follows: 0,100 g of iron powder was dissolved in 5 cmof nitric acid, diluted 1:1, add 25 cmof water and heated to boiling. The solution was cooled, transferred to a volumetric flask with a capacity of 1 DMand adjusted to the mark with nitric acid, diluted 1:9.
1 cmof solution A contains 0.1 mg of iron.
Solution; prepared as follows: 4 cmof solution A is placed in a volumetric flask with a capacity of 100 cmand adjusted to the mark with nitric acid, diluted 1:9.
1 cmof the solution contains 4 µg of iron.
Solution prepared on the day of application.
Distilled water according to GOST 6709, double-distilled in quartz apparatus.
Iron powder restored brand MLB-1 according to GOST 9849.
(Changed edition, Rev. N 2, 3
).
3.3. Analysis
3.3.1. The weight India weight of 1,000 g was placed in a flask with a capacity of 50 cm, is dissolved in 10 cmof hydrochloric acid diluted 1:1, pour two drops of hydrogen peroxide and evaporated to small volume.
The solution after dissolution of sample of indium with a mass fraction of iron ·10% transferred to a volumetric flask with a capacity of 50 cm, adjusted to the mark with water and take aliquote part 5 cm, which is placed in a volumetric flask with a capacity of 25 cm.
The solution after dissolution of sample of indium with a mass fraction of iron ·10% was placed in a volumetric flask with a capacity of 25 cm. Further analysis are the same.
Pour 2.5 cmof nitric acid, diluted 1:9, 3 cmof a solution of ammonium Rodenstock, 12 cmof acetone, adjusted to the mark with water and mix.
The optical density of solutions measured on photoelectrocolorimeter using the filter with a light transmission region of 500−520 nm in a cuvette with a thickness of the light absorbing layer was 50 mm.
Solution comparison in the measurement of optical density is water.
At the same time under the same conditions conduct control experience with reagents for inclusion in the analysis result of the relevant amendment.
The amount of iron in kalorimetricheskim volume set calibration schedule.
(Changed edition, Rev. N
2, 3).
3.3.2. Building a graded graphics
In a volumetric flask with a capacity of 25 cmis placed 0; 0,5; 1,0; 1,5; 2,0 and 2,5 cmstandard solution, which corresponds to 0, 2, 4, 6, 8 and 10 mg iron, pour 2.5 cmof nitric acid, diluted 1:9.3 cmsolution Rodenstock ammonium, 12 cmof acetone, adjusted to the mark with water and further analysis are as indicated in claim
On the found values of optical density and corresponding grades of iron to build the calibration graph.
3.4. Processing of the results
Mass fraction of iron () in percent is calculated by the formula
,
where — the amount of iron was found in the calibration schedule, mcg minus reference experiment;
— volume of the volumetric flask for dilution, cm;
— aliquotes volume of the solution taken for colorimetrically, cm;
— the weight of the portion India,
3.4.1. For the results analysis be the arithmetic mean of results of three parallel measurements.
The difference between the largest and smallest of the three results of parallel measurements with a confidence probability of 0.95 does not exceed the value of permissible differences of the three results of parallel measurements calculated by the formula
,
where is the arithmetic mean of the three results of parallel measurements.
The difference between the smaller and larger of the two results of the analysis of the same samples with a confidence level of 0.95 does not exceed the value of permissible differences of the two analyses is calculated according to the formula
,
where — the average of the two matched analyses.
(Changed edition, Rev. N 2).