GOST 13637.4-93
GOST 13637.4−93 Gallium. Method for determination of iron
GOST 13637.4−93
Group B59
INTERSTATE STANDARD
GALLIUM
Method for determination of iron
Gallium.
Method for the determination of iron
AXTU 1709
Date of introduction 1995−01−01
Preface
1. DEVELOPED by the Interstate technical Committee 104 «of the Semiconductor and rare metals products. Especially pure metals», State Institute of rare metals (Giredmet)
INTRODUCED by Gosstandart of Russia
2. ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 4−93 of 19 October 1993)
The adoption voted:
| The name of the state | The name of the national authority standardization |
| The Republic Of Armenia |
Armastajad |
| The Republic Of Belarus |
Belstandart |
| The Republic Of Kazakhstan |
Gosstandart Of The Republic Of Kazakhstan |
| The Republic Of Moldova |
Moldovastandart |
| Russian Federation |
Gosstandart Of Russia |
| Turkmenistan |
Turkmenistanand |
| The Republic Of Uzbekistan |
Standards |
| Ukraine |
Gosstandart Of Ukraine |
3. Resolution of the Committee of the Russian Federation for standardization, Metrology and certification from
4. REPLACE GOST 13637.4−77
INFORMATION DATA
REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced | Paragraph number section |
| GOST 3759−75 |
Sec. 2 |
| GOST 4139−75 |
Sec. 2 |
| GOST 5830−79 |
Sec. 2 |
| GOST 6691−77 |
Sec. 2 |
| GOST 6709−72 |
Sec. 2 |
| GOST 11125−84 |
Sec. 2 |
| GOST 13637.0−93 |
Sec. 1 |
| GOST 14261−77 |
Sec. 2 |
| GOST 14262−78 |
Sec. 2 |
| GOST 24104−88 |
Sec. 2 |
| GOST 24147−80 |
Sec. 2 |
| GOST 25086−87 |
5.3 |
This standard specifies the visual-photometric method for determination of iron in the range of mass fraction from 2·10to 1·10
%.
The method is based on extraction and subsequent concentration of the visual-photometric determination of iron in a thiocyanate. Gallium does not interfere with the determination.
1. GENERAL REQUIREMENTS
General requirements for methods of analysis and safety requirements according to GOST 13637.0.
2. APPARATUS, REAGENTS AND SOLUTIONS
Laboratory scales of the 1st class according to GOST 24104*.
_______________
* On the territory of the Russian Federation GOST 24104−2001. — Note the manufacturer’s database.
Box of Plexiglas.
The electric stove, covered with a quartz cuvette.
Pipettes with a capacity of 1 cm.
Cylinder measuring capacity 10 cm.
Volumetric flasks with a capacity of 100 and 1000 cm.
Quartz glasses with a capacity of 50 cmwith quartz lids.
Set of cylinders for the photometry of colorless glass with ground stoppers with a height of 20 cm and a diameter of 1.5 cm.
Hydrochloric acid of high purity according to GOST 14261, double-distilled in quartz apparatus, a concentration of 6 mol/DM.
Nitric acid of high purity according to GOST 11125, purified by distillation in a quartz apparatus.
Distilled water according to GOST 6709, further purified on ion-exchange column.
A mixture of hydrochloric, nitric acids and water, taken in the ratio 1:1:1, freshly prepared.
Urea according to GOST 6691.
Aluminium chloride according to GOST 3759.
Potassium rodanistye according to GOST 4139, purified from iron:
200 g Rodenstock potassium dissolve in low heat in 100 cmof water, after dissolution add 50 mg of aluminum chloride and precipitated hydroxide of iron and aluminium by adding a few drops of ammonia, the next day the precipitate was filtered off, discarding first portion of filtrate.
Isoamyl alcohol according to GOST 5830.
The aqueous ammonia of high purity according to GOST 24147.
Amylacetate (amyl ether acetic acid).
Sulfuric acid of high purity according to GOST 14262, concentrated and the concentration of 9 mol/DM.
Alum salesonline.
A solution of iron (main), 0,8635 g gentoomaniac alum dissolved in 10−15 cmof distilled water, add 1−2 cm
of sulphuric acid concentration 9 mol/DM
, bring the volume of solution in a volumetric flask with a capacity of 1 DM
to the mark with water and mix.
1 cmof the solution contains 100 mcg of iron.
More dilute working solutions of iron are prepared by successive dilution with water in volumetric ratio of 1:9 on the day of use.
3. PREPARATION FOR ASSAY
3.1. Sample preparation
A sample of gallium is washed from surface contamination with hydrochloric acid at room temperature for several minutes, and then with several portions of water.
3.2. Preparation of the solution comparison
Five cylinders for the electrophoretic enter 0,1; 0,2; 0,3; 0,4; 0,5 cmworking solution of iron with a content of 1 g/cm
, add 1 cm
of a hydrochloric acid solution, bring the solution volume up to 10 cm
of water, pour 0.5 cm
of a solution of potassium Rodenstock, mix, and add 1 cm
isoamyl alcohol or amylacetate and repeatedly shaken.
At the same time carried out two test experience, taking in the colour of the cylinders the same reagents and in the same amounts as in the analysis of the sample.
The solutions comparison is prepared concurrently with the sample analysis. Solutions comparison sustainable for 20−30 min.
4. ANALYSIS
A portion of gallium by mass of 0.5 g, purified according to claim 3.1, is placed in a quartz beaker, pour 6 cmof a mixture of hydrochloric, nitric acids and water, the glass cover quartz cover. Gallium is dissolved with moderate heating on a hot plate. All operations associated with heating, conduct in Boxing. Upon completion of the dissolution, the cover is removed and the solution evaporated to dryness. Then pour 1 cm
of a solution of hydrochloric acid and again evaporated to dryness. For complete removal of nitric acid, this operation is repeated two or three times. Next, the dry residue was dissolved with heating in 1 cm
of the hydrochloric acid solution is poured 10 cm
of water is added at the tip of a spatula of urea and heated to boiling. After cooling, transfer the solution into the cylinder for the photometry, if necessary the volume was adjusted solution with water to 10 cm
, flow 1.0 cm
of a solution of potassium Rodenstock, stirred, poured 1 cm
isoamyl alcohol or amylacetate and repeatedly shaken.
The color of the organic layer of the sample solution and the reference experiment are compared with the color of the organic layer solutions comparison in the cylinders and find the solution comparison, the color of the organic layer closest to the color of the organic layer of the sample solution. The amount of iron in the control experiment shall not exceed 0.1 micrograms.
5. PROCESSING OF THE RESULTS
5.1. Mass fraction of iron () in the sample in percent is calculated by the formula
where is the mass of iron in sample solution, µg,
— the adjustment value in the reference experiment, mcg,
the weight of gallium,
5.2. The result of the analysis taking the arithmetic average of the two results of parallel measurements carried out from separate batches.
The allowable discrepancy of the two results of parallel measurements and the two results of the analysis (the difference between larger and smaller) at a confidence probability of 0.95 is given in the table.
| Mass fraction of iron, % |
Allowable difference, % |
2·10 |
2·10 |
5·10 |
2·10 |
1,0·10 |
0,4·10 |
Allowable differences for intermediate values of the mass fraction of iron calculated using linear interpolation.
5.3. Control of the correctness analysis is carried out by additives according to GOST 25086.
