GOST 13637.8-93
GOST 13637.8−93 Gallium. Method for the determination of tellurium
GOST 13637.8−93
Group B59
INTERSTATE STANDARD
GALLIUM
Method for the determination of tellurium
Gallium.
Method for the determination of tellurium
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 13637.8−77
INFORMATION DATA
REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Paragraph number section |
| GOST 2062−77 | Sec. 2 |
| GOST 4109−79 | Sec. 2 |
| GOST 4234−77 | Sec. 2 |
| GOST 4658−73 | Sec. 2 |
| GOST 5456−79 | Sec. 2 |
| GOST 5848−73 | Sec. 2 |
| GOST 6709−72 | Sec. 2 |
| GOST 10652−73 | Sec. 2 |
| GOST 11125−84 | Sec. 2 |
| GOST 13637.0−93 | Sec. 1 |
| GOST 14261−77 | Sec. 2 |
| GOST 14262−78 | Sec. 2 |
| GOST 18300−87 | Sec. 2 |
| GOST 20490−75 | Sec. 2 |
| GOST 24104−88 | Sec. 2 |
| GOST 24363−80 | Sec. 2 |
| GOST 25086−87 | 4.4 |
| GOST 27068−86 | Sec. 2 |
This standard specifies a method for the inversion, alternating-current polarography for the determination of tellurium in Gaul (at the mass fraction of tellurium from 5·10to 1·10
%).
The method is based on the allocation of tellurium in elemental form in the collector — sulfur and the determination of its content by the method of inversion, alternating-current voltammetry in weakly acidic solution of potassium chloride and ethylenediaminetetraacetic acid.
1. GENERAL REQUIREMENTS
General requirements for methods of analysis and security 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.
Polarograph PPT-1 and PU-1 with the stationary mercury electrode and electrolytic cell polarograph with a remote anode compartment. The anode compartment is filled with metallic mercury and a saturated solution of potassium chloride.
Tile electric laboratory with a capacity of 400 and 800 watts.
Water bath.
The roughing pump brand VM-461М or similar.
Glass vials with a capacity of 15 cm.
Sticks to glass.
Conical flasks with a capacity of 250 cm.
Funnels, glass, with a diameter of 75 mm.
Volumetric flasks with a capacity of 25; 50; 1000 cm.
Beakers with a capacity of 100; 500; 1000 cm.
Measuring cylinders with a capacity of 5 and 10 cm.
Measuring cylinders with ground stoppers with a capacity of 5 and 10 cm.
Pipette with divisions of 0,1; 0,2; 1; 2 cm.
The quartz crucibles with a capacity of 50 cm.
The chemical glasses with a capacity of 25; 100; 200; 1000 cm.
Watch-glasses with a diameter of 70 mm.
Indicator paper «Rfat» pH of 3.4 and 1.9.
Filters «white ribbon».
Filter paper.
Sulfuric acid of high purity according to GOST 14262, diluted 1:1 and 1:3.
Nitric acid of high purity according to GOST 11125.
Hydrochloric acid of high purity according to GOST 14261, concentrated, and solutions of concentration 8; 6; 3; 2,3 and 1 mol/DM.
Formic acid according to GOST 5848.
Reverse Aqua Regia — a mixture of concentrated nitric and hydrochloric acids in a volume ratio of 3:1.
Distilled water according to GOST 6709.
Bidistilled water: distilled water is poured into the flask of the distillation apparatus with a capacity of 2 DM, is poured 1 g of potassium hydroxide and potassium permanganate to intense staining. The solution was heated. Collect the middle fraction of the distillate component
of the taken volume of distilled water. The first and third fractions discarded.
Potassium hydroxide according to GOST 24363.
Potassium permanganate according to GOST 20490.
Hydroxylamine hydrochloride according to GOST 5456, solution concentration of 100 g/cmin a solution of hydrochloric acid concentration of 8 mol/DM
.
The washing liquid: 200 cmof the hydrochloride of hydroxylamine concentration of 100 g/l
solution of hydrochloric acid is poured into a measuring flask with a capacity of 1 DM
and adjusted to the mark with distilled water.
Chernovetskiy sodium (sodium thiosulfate) 5-water according to GOST 27068, recrystallized, aqueous solution concentration of 100 g/DM.
Potassium chloride according to GOST 4234, OS.CH., a saturated solution in bidistilled water.
Bromine according to GOST 4109.
Salt is the disodium Ethylenediamine-,
,
,
-tetraoxane acid, 2-water (Trilon B) according to GOST 10652.
Mercury brands r0 according to GOST 4658.
Background polarographic: 200 g of potassium chloride and 1 g Trilon B dissolved in distilled water. The solution was transferred to volumetric flask with a capacity of 1 DM. the pH of the solution set of 2.8 (on indicator paper) with hydrochloric acid concentration of 3 mol/DM
.
The technical rectified ethyl alcohol according to GOST 18300 is used when charging the electrodes in accordance with the instructions for polarography.
Tellurium of high purity.
A solution of basic tellurium: 100 mg of tellurium dissolved in 20 cmof distilled hydrochloric acid with addition of nitric acid drop by drop when heated. The solution was transferred to volumetric flask with a capacity of 1 DM
and bring to mark distrurbance water.
1 cmof the solution contains 100 micrograms of tellurium.
A solution of tellurium production: 10 cmbasic solution of tellurium is poured into a measuring flask with a capacity of 100 cm
, made up of the polarographic background to the mark and mix.
1 cmof the solution contains 10 micrograms of tellurium.
More dilute working solutions of tellurium is prepared by successive dilution of the polarographic backgrounds in a volume ratio 1:9 on the day of use.
3. ANALYSIS
3.1. Dissolution samples
A portion of gallium by mass of 1 g was dissolved with heating in 10 cmreverse Aqua Regia into a crucible with a capacity of 50 cm
under the watch glass. The resulting solution was evaporated to dryness. Denitration then spend the remainder on a water bath. For this purpose the residue is treated first with distilled water, and then formic acid, which is poured carefully dropwise. After the complete termination of allocation of brown fumes of nitrogen oxides, the residue twice treated with formic acid (portions for 2 cm
). Then, the contents in the crucible was treated 4 times with distilled water in portions of 5 cm
, washing the walls of the crucible and each time uparima the contents of the crucible to dryness on a water bath. In the end should disappear the smell of formic acid.
The dry residue is dissolved in 10 cmof a solution of hydroxylamine hydrochloride. The solution was transferred to a test tube with a capacity of 15 cm
. The tube was placed in boiling water bath. The solution was added three times at 1 cm
of a solution of sodium servational at intervals of 1 h. the Tube was kept in boiling bath for another 2 h and left overnight. The next day the precipitate of sulphur is filtered through the filter «white ribbon» and sequentially washed 15 times with wash liquid, and 10 times with bidistilled water.
The washed precipitate is transferred to double-distilled water (15−20 cm) crucible with a capacity of 50 cm
. There also add 1 cm
of sulfuric acid (1:1), 0.2 cm
of a saturated solution of potassium chloride and five drops of bromine. The solution is evaporated on a sand bath to dryness. Treatment with bromine again, if the dry residue contains dark inclusions. The dry residue is calcined on the tile, with 800 W power up to complete disappearance of the smell trioxide
sulfur.
3.2. Polarographically
To the cooled crucible with the residue add 25 cmof the polarographic background. The crucible is carefully heated until the precipitate has fully dissolved, cool the contents and transfer it into a measuring cylinder with a capacity of 25 cm
. The volume was adjusted solution to the mark with bidistilled water. Polarographically are analyzed solution in the cell polarograph with a remote anode compartment. The size of the stationary mercury drop must match 20 ticks of the clock indicator polarograph. The accumulation potential of minus 0.6 volts, a duration of accumulation of 1−3 min. Scan cathode 5 mV/s the peak Potential of tellurium of about minus 0,80 V.
3.3. Transcript of voltammograms
The peak height is measured vertically, is drawn through the peak at the intersection with a tangent connecting the bases of the branches peak. Each of the peak heights should not differ from the average height by more than 0.2
. If the height of the first peak differs from the average
by more than 0.2
, the height of the first peak is not considered.
Mass fraction of tellurium in the sample determined by the method of additions. The addition of the diluted working solution of tellurium not exceeding 0.3 cmis introduced into the entire volume polarographic solution.
The solution with the addition of polarographic the same way as the analyzed solution. Supplement should to increase the mass of tellurium in polarographic solution and the peak height of 2−3 times, if the mass fraction of tellurium in the sample , calculated according to claim 4.1, at least 5·10
%. At a lower content of tellurium in the sample of the additive must be 0.05 ág of tellurium.
With each series of samples is carried out two test experience.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of tellurium () in percent is calculated by the formula
where is the mass of tellurium in addition, mcg,
— arithmetic average peak height prerogrative of the sample solution minus the arithmetic mean value of the peak height of tellurium in a control experiment, mm
the weight of gallium in the solution polarographically, g,
— arithmetic average peak height of the sample solution with the additive minus the arithmetic mean value of the peak height of tellurium in a control experiment, mm
— polarographic volume of sample solution 25 cm
,
— volume Supplement, see
.
4.2. The result of the analysis taking the arithmetic average of the two results of parallel measurements carried out from separate batches.
4.3. The allowable discrepancy of the two results of parallel measurements and the two results of the analysis (the difference between larger and smaller) with confidence probability of 0.95 is given in the table.
| Mass fraction of tellurium, % |
Allowable difference, % |
5·10 |
3·10 |
1,0·10 |
0,5·10 |
5·10 |
2·10 |
1,0·10 |
0,3·10 |
Permitted discrepancies for the intermediate mass fraction of tellurium calculated using linear interpolation.
4.4. Control of the correctness analysis is carried out by additives according to GOST 25086.
