GOST 12645.9-83
GOST 12645.9−83 indium. Chemical-spectral method of determination of thallium (with Amendments No. 1, 2)
GOST 12645.9−83
Group B59
STATE STANDARD OF THE USSR
INDIUM
Chemical-spectral method of determination of thallium
Indium. Chemical spectral method for determination of thallium
GST 17 2161
AXTU 1709
Date of introduction 1984−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
L. K. Larina (supervisor)
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
Change No. 2 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 2062−77 | Sec. 2 |
| GOST 4109−79 | « |
| GOST 4328−77 | « |
| GOST 4461−77 | « |
| GOST 6709−72 | « |
| GOST 10297−94 | « |
| GOST 11125−84 | « |
| GOST 12645.0−83 | 1.1 |
| GOST 18300−87 | Sec. 2 |
| GOST 18337−80 | « |
| GOST 19908−90 | « |
| GOST 22300−76 | Sec. 2 |
| GOST 22306−77 | 1.1 |
4. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
5. REVISED (March 1998) with Amendments No. 1, 2 approved in December 1987-June 1996 (IUS 3−88, 9−96)
This standard specifies the chemical-spectral method of determination of thallium in India brands Ин000, Ин000у when the mass fraction of thallium from 7·10to 2·10
%.
The method is based on preliminary extraction separation of trivalent thallium isobutyl ether acetic acid of bromatological environment and spectrographic analysis of the resulting concentrate.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis and security requirements — according to GOST and GOST 12645.0 22306.
(Changed edition, Rev. N 1).
2. APPARATUS, REAGENTS AND MATERIALS
The quartz spectrograph medium dispersion of any type with being a lighting system, cracks.
The generator is activated the arc AC.
A constant current source providing a voltage of at least 200 V and a current not less than 20 A.
Microphotometer designed to measure pucherani spectral lines.
Libra torsion bar type W with a weighing error of no more than 0.001 g.
Analytical scale with a weighing error of no more than 0,0002 g.
Spectromancer of PS-18.
The infrared lamp of any type from lab type autotransformer RNO-250−2.
Mortar made of organic glass with a pestle.
PTFE dishes (glasses, cups).
Ware quartz (separating funnels, cups) according to GOST 19908.
Distilled water according to GOST 6709.
The isobutyl ester of acetic acid according to GOST 22300.
Nitric acid according to GOST 4461, double-distilled in quartz apparatus or
nitric acid brands high purity according to GOST 11125.
Bromatologia acid according to GOST 2062, solutions (NVG)=1 and 7 mol/DM
. The concentration of acid is set by titration with sodium hydroxide solution.
Sodium hydroxide according to GOST 4328, solution (NaOH)=1 mol/DM
.
The technical rectified ethyl alcohol according to GOST 18300.
Sodium chloride brand OS.H.
Indium oxide, obtained from India brand Ин00 according to GOST 10297.
Bromine according to GOST 4109.
Thallium GOST 18337*.
______________
* On the territory of the Russian Federation GOST 18337−95. — Note the manufacturer’s database.
Electrodes of graphite rods stamps-2 or b-3 6 mm in diameter with a crater depth of 3 mm and a hole diameter of 4 mm.
Powder graphite obtained from graphite rods stamps-2 or b-3.
Photographic plates spectrographic type SFC-02 or NT-2SV.
Note. Allowed the use of devices with photovoltaic spectra and other spectral instruments, other reagents and materials, providing the accuracy that rivals regulated in this standard.
(Changed edition, Rev. N 1, 2).
3. PREPARATION FOR ASSAY
3.1. A solution of thallium: 0,150 g of metallic thallium is dissolved in 10 cmof nitric acid under mild heating, and the solution heated to boiling, cooled, transferred quantitatively into a flask with a capacity of 100 cm
and adjusted to the mark with water.
1 cmof the solution contains 1.5 mg of thallium.
(Changed edition, Rev. N 2).
3.2. Samples comparison. The basis for the preparation of samples of comparison is a graphite powder containing 2% of indium oxide and 2% sodium chloride.
For preparation of the main reference sample containing 0.03% of thallium in a Teflon Cup was placed 5.0 g of graphite powder and a drop of 1 cmof a solution of thallium. With the introduction of the solution monitor the solution, impregnating a basis, does not impinge on the sides and bottom of the Cup. To do this, as the introduction of a solution of graphite powder is dried under a lamp. To remove nitric acid vapor mixture is calcined in the muffle for 30 min at a temperature of (300±20) °C.
The resulting mixture was thoroughly stirred in a mortar for 60 min with a Dilution of the primary and newly prepared samples based get series of working samples of the comparison in accordance with the table.
| Sample number comparison | Mass fraction of thallium in the sample, % | The number of diluted sample | The number of bases needed for the dilution |
| The basic pattern | 3·10 |
- | - |
| 1 | 3·10 |
1,000 primary sample | 9,000 |
| 2 | 1·10 |
2,500 sample N 1 | 5,000 |
| 3 | 3·10 |
0,600 «N 1 | 5,400 |
| 4 | 1·10 |
1,000 «N 2 | 9,000 |
| 5 | 5·10 |
3,000 «N 4 | 3,000 |
(Changed edition, Rev. N 1, 2).
3.3. A buffer mixture of the graphite powder is administered 2% sodium chloride, mixing time — 60 min.
3.4. Samples comparisons, base and buffer mixture was stored in buksh or tightly sealed jars.
(Changed edition, Rev. N 1).
4. ANALYSIS
4.1. India sample weight of 0.5 g was placed in Teflon beaker or Cup with a capacity of 50 cmand dissolved in 4 cm
of solution bromatological acid
(HBR)=7 mol/DM
by heating under an infrared lamp. The cooled solution was poured two drops of bromine and 20 cm
of water, shaken for 2 min and left for 2 min for the oxidation of monovalent thallium to trivalent.
The prepared solution transferred to a separatory funnel, add 15 cmisobutyl ester of acetic acid and shake for 2 min. After separation the aqueous layer is discarded and the organic washed with 5 cm
of a solution bromatological acid
(HBR)=1 mol/DM
. When washing the shaking should not be strong. Extract is poured in Teflon Cup, as there will interfere with 50 mg of a mixture of buffer and dried under an infrared lamp. The sample degradation, the oxidation of thallium and evaporation of the concentrate should be carried out in Teflon dishes to prevent sorption of thallium in the glass. Enrichment is carried out in three batches. At the same time are controlling experience with chemicals for inclusion in the result of the analysis of the relevant trampling
Ki.
4.2. Samples of comparison and the resulting concentrate 20 mg placed in the craters of graphite electrodes. The spectra are photographed on a quartz spectrograph in the arc AC or DC power 15 And the photographic plates of type SFC-02, the SFC-03, NT-2SV. Exposure 15 s, the slit Width of the spectrograph 0,0020−0,025 mm.
4.1, 4.2. (Changed edition, Rev. N 1, 2).
5. PROCESSING OF THE RESULTS
5.1. In the spectrogram, using microphotometry measure of the blackening of the line of thallium 276,7 nm and the surrounding background to the right of the line. The calibration graphs are built in coordinates 
— line,
— background,
— mass fraction of thallium in the samples comparison).
Mass fraction of thallium () in percent is calculated by the formula
where is the mass of the concentrate, mg;
— the weight of the portion of the original sample, mg;
— mass fraction of thallium that was found in the calibration schedule, minus the reference experiment, %.
(Changed edition, Rev. N 1).
5.2. The reproducibility of the analysis of the same sample are characterized by a relative standard deviation amounting to 0.10.
The convergence of the results of parallel measurements is characterized by the relative standard deviation, amounting to 0.10.
For the results analysis be the arithmetic mean of results of three parallel measurements obtained on one disc (each simultaneous determination of the two spectrograms).
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, is calculated according to the formula
where is the arithmetic average of the three matched 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
calculated by the formula
— the average of the two matched analyses.
(Changed edition, Rev. N 1, 2).
