GOST 1367.9-83
Group B59
INTERSTATE STANDARD
ANTIMONY
GOST
1367.9−83
Method for the determination of tellurium
Antimony. Method for the determination of tellurium AXTU 1709
1 the Establishment of the USSR State Committee on standards or on 16 December 1983 No. 6013 date of introduction is established 01.01.8 S
Africanis validity based on a Protocol 4−93 Ns mittelst the governmental Council, but standarten. Metrology and certification (ICS 4−94)
This standard specifies a method for the inversion perimentally polarography for the determination of tellurium from 5 10~b 5−10-5 in the antimony brand Swoooop.
The method is based on the recovery of tellurium to the elemental state by hydroxylamine and sodium Chernovetskiy of hydrochloric acid solution of the sample and its coprecipitation with grey. The precipitate sulphur, tellurium is dissolved in sulfuric acid with bromine. Tellurium is determined polarographically in weak acidic solution of potassium chloride.
(Amended, Izch. No. 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis and security requirements — according to GOST 1367.0−83.
2. APPARATUS, REAGENTS AND SOLUTIONS
Polarograph re me streaming type PU-1.
Beakers, glass, laboratory for GOST 25336−82 with a capacity of 50. 100 cm3.
Volumetric flasks according to GOST 1770−74 with a capacity of 100 cm3.
Test tube glass according to GOST 25336−82 capacity 15 cm3.
Beakers according to GOST 1770−74 with a capacity of 50 cm.
Pipette with divisions for NTD with a capacity of 1, 2, 5. 10 cm3.
The cylinders are graded according to GOST 1770−74 with a capacity of 50 cm5.
Nitric acid of high purity according to GOST 11125−84.
Formic acid according to GOST 5X48−73.
Hydrochloric acid of high purity according to GOST 14261−77 and 8 mol/DM' of the solution.
Bideterminant water (double-distilled water); prepared by distillation of distilled water in a quartz distillation apparatus.
Hydroxylamine hydrochloride according to GOST 5456−79, the solution with mass fraction 10% in 8 mol/DM3 hydrochloric acid solution.
Chernovetskiy sodium (sodium thiosulfate) according GOST 27068−86, recrystallized NY. a solution with a mass fraction of 10%.
Fluid flushing: a solution with a mass fraction of 10% hydroxylamine hydrochloride in 8 mol/DM' hydrochloric acid solution is diluted five times with double-distilled water.
Sulfuric acid of high purity according to GOST 14262−78 and diluted 1:1.
Potassium chloride according to GOST 4234−77, OS… a saturated solution in double-distilled water.
Bromine in GOST 4109−79.
Official edition Reprinting is prohibited
Edition with amendments No. J, approved «March 1989 (IUS 6−89).
57
C. 2 GOST 1367.9−83
Salt and sodium d with unit ethylendiaminetetraacetic acid (Trilon B) according to GOST 10652−73.
Background polarographic: 200 g of potassium chloride and 1 g Trilon B rastport 1 DM' belstil-Lata and dilute hydrochloric acid to bring the pH to 2.8 (on flat paper or on the testimony of poteniometer).
Tellurium on the other 48−6-99−87.
Standard solutions of tellurium.
Solution L: 0.1 g of metallic tellurium was placed in a beaker with a capacity of 100 cm5 and dissolved by heating in 20 cm5 concentrated hydrochloric acid with a dropwise addition of nitric acid.
After dissolution, the solution was cooled, transferred to a volumetric flask with a capacity of NO) cm' and adjusted with double-distilled water to the mark, mix.
1 cm3 of solution contains 1 mg of tellurium.
Solution B: 1 cm3 solution L poured into a measuring flask with a capacity of 100 cm', made up of the polarographic background to the mark and mix: prepare on day of use.
1 cm* solution B contains 0.01 mg of tellurium.
(Changed edition, Rev. No. 1).
3. ANALYSIS
3.1. A portion of the antimony brand Swoooop weighing 0.5 g were placed in a glass with a capacity of 50 cm3, pour 5 cm' of nitric acid. 2 cm3 of concentrated hydrochloric acid, cover the watch glass and decompose in a water bath. The contents of the glass is evaporated, and then to the dry residue add 10 cm3 of double-distilled water and repeat the evaporation.
To the dry residue are added dropwise formic acid. The decomposition of nitrates and removing formic acid is carried out in a water bath. After the complete termination of allocation of brown fumes of nitrogen oxides when next addition of formic acid, the residue in the beaker twice treated with an acid (portions for 2 cm3). Then the rest of the Cup three or more times treated with double-distilled water (in portions of 5 cm3), carry out the evaporation of solution to dryness on a water bath until the odor of formic acid.
The dry residue is dissolved in 10 cmj of the hydrochloride hydroxylamine. The solution was transferred to a test tube with a capacity of 15 cm3, add 1 cm3 chernovetskogo sodium and prevent the tube in a boiling water bath for 1.5−2 h. Then to the solution add 1 cm3 solution of sodium servational and again the tube was kept in boiling water bath for I-2 hours and left for approximately 12 h. Then the precipitate of sulphur was filtered through a filter with a white ribbon and sequentially washed 15 times with the washing liquid three times a bidis-Telecom. The washed precipitate is transferred 15 cm3 of bidistillate in a glass with a capacity of 50 cm3, flow I cm3 of dilute sulfuric acid, 0.2 cm3 of a saturated solution of potassium chloride and five drops of bromine. The solution is evaporated on a sand bath until complete disappearance of the smell of sulfur treharne.
After cooling, the beaker was added 30 cm3 of the polarographic background. A glass of slightly warmed until complete dissolution of the precipitate, cool and transfer the solution into a measuring cylinder, bringing the solution volume to 30 cm3 bidistillate.
3.2. Prerogrative of the analyzed solution are in the cell with an external saturated calomel anode with application of a stationary mercury electrode. Potential savings minus 0.60 In, the duration of accumulation of 1−3 min, the cathodic scan. The peak potential of about minus 0,80 V. Polarogram of each solution is removed 3−4 times. The peak height is measured vertically, is drawn through the top of the peak to the intersection with a tangent connecting the bases of the branches peak. The concentration of tellurium in solution was determined by method of additions. With each series of samples carried out three control experience.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of tellurium (L) in percent is calculated by the formula
t, ■ //,
* = -7,-TG-
t (N,2~ #,)
where t, is the mass of tellurium in addition, mcg:
GOST 1367.9 -83 C. 3
I, — arithmetic average peak height of the sample solution minus the average height of peaks in control experiments, mm:
N2 — arithmetic average peak height of the solution of the sample with the additive minus the average height of the greenhouse control experiments, mm (difference And2~N1 must not be less than //, and 3//,), t is the weight of antimony,
4.2. The difference between the two results of parallel measurements and the difference of two analysis results with a confidence probability P = 0.95 does not exceed the allowable absolute differences of precision and reproducibility, are given in the table.
Missoula the proportion of tellurium. SP Absolute maximum figure walking. % the convergence of the NOSE 11 of ro AND CL m osti From 0.000005 to 0.000010 incl. 0.000004 0.000005 SV. 0,000010 «0,000020 • 0,000005 0.000006 * 0.00002 * 0,00005 * 0.0000! 0,00002
| Missoula the proportion of tellurium. Zr | The absolute maximum circulation Fig. % | |
| convergence | The NOSE 11 of ro AND CL m osti | |
| From 0.000005 to 0.000010 incl. | 0.000004 | 0.000005 |
| SV. 0,000010 «0,000020 • | 0,000005 | 0.000006 |
| * 0.00002 * 0,00005 * | 0.0000! | 0,00002 |
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