GOST 13047.25-2002
INTERSTATE STANDARD
NICKEL. COBALT
METHODS FOR DETERMINATION OF SELENIUM IN NICKEL
THE INTER-STATE COUNCIL
FOR STANDARDIZATION, METROLOGY AND CERTIFICATION
Minsk
Preface
1 DEVELOPED by Interstate technical committees for standardization MTK 501 Nickel and MTC 502 «Cobalt», JSC «Gipronikel ' Institute»
INTRODUCED by Gosstandart of Russia
2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol № 21 dated may 30, 2002)
The adoption voted:
| The name of the state | The name of the national authority for standardization |
| The Republic Of Azerbaijan | Azgosstandart |
| The Republic Of Armenia | Armastajad |
| The Republic Of Belarus | Gosstandart Of The Republic Of Belarus |
| Georgia | Gosstandart |
| The Kyrgyz Republic | Kyrgyzstandard |
| The Republic Of Moldova | Moldovastandart |
| Russian Federation | Gosstandart Of Russia |
| The Republic Of Tajikistan | Tajikstandart |
| Turkmenistan | The MDCSU «Turkmenstandartlary» |
| The Republic Of Uzbekistan | Standards |
| Ukraine | Gosstandart Of Ukraine |
3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated 17 September 2002 No. 334-St inter-state standard GOST 13047.25−2002 introduced directly as state standard of the Russian Federation from July 1, 2003
4 INTRODUCED FOR THE FIRST TIME
The CONTENTS
1 Scope 2 Normative references 3 General requirements and safety requirements 4 a spectrophotometric method 4.1 Method of analysis 4.2 measuring instruments, auxiliary devices, materials, reagents, solutions 4.3 Preparation for analysis 4.4 analysis 4.5 Processing the analysis results 4.6 accuracy Control analysis 5 Atomic absorption method 5.1 Method of analysis 5.2 measurement Means, auxiliary devices, materials, reagents, solutions 5.3 Preparation for assay 5.4 analysis 5.5 Processing of analysis results 5.6 Control of accuracy of analysis Appendix A. Bibliography |
GOST 13047.25−2002
INTERSTATE STANDARD
NICKEL. COBALT
Methods for determination of selenium in Nickel
Nickel. Cobalt.
Methods for determination of selenium in nickel
Date of introduction 2003−07−01
1 Scope
This standard specifies the spectrophotometric and atomic absorption methods for the determination of selenium at mass fraction of from 0.0001% to 0,0050% in primary Nickel GOST 849.
2 Normative references
The present standard features references to the following standards:
GOST 849−97 Nickel primary. Specifications
GOST 3118−77 hydrochloric Acid. Specifications
GOST 3760−79 Ammonia water. Specifications
GOST 4461−77 nitric Acid. Specifications
GOST 5789−78 Toluene. Specifications
GOST 5848−73 formic Acid. Specifications
GOST 9722−97 Nickel Powder. Specifications
GOST 10157−79 Argon gaseous and liquid. Specifications
GOST 10298−79 Selenium technical. Specifications
GOST 10484−78 hydrofluoric Acid. Specifications
GOST 10652−73 Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B)
GOST 11125−84 nitric Acid of high purity. Specifications
GOST 13047.1−2002 Nickel. Cobalt. General requirements for methods of analysis
GOST 14261−77 hydrochloric Acid of high purity. Specifications
GOST 24147−80 aqueous Ammonia of high purity. Specifications
3 General requirements and safety requirements
General requirements for methods of analysis and safety requirements when performing work — according to GOST 13047.1.
4 a spectrophotometric method
4.1 Method of analysis
The method is based on measuring light absorption at a wavelength of 330 nm of a solution of complex compounds of selenium onphenylendiamine after a preliminary extraction of the toluene.
4.2 measuring instruments, auxiliary devices, materials, reagents, solutions
Spectrophotometer or photoelectrocolorimeter, which provides measurements in the wavelength range of 320 — 340 nm.
pH meter (ion meter) for measurements in the pH range 0.9 and 1.1.
Nitric acid according to GOST 4461, if necessary, purified by distillation, or according to GOST 11125, diluted 1:1.
Hydrochloric acid according to GOST 3118, if necessary, purified, or GOST standards, 14261, diluted 1:2 and 1:4.
Acid chloride in [1], diluted 1:99.
Formic acid according to GOST 5848.
Ammonia water according to GOST 3760, if necessary, according to GOST 24147, diluted 1:1.
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid (Trilon B) according to GOST 10652, solution mass concentration of 0.04 g/cm3.
on-Phenylendiamin in [2], solution of the mass concentration of 0.01 g/cm3.
Toluene according to GOST 5789, if necessary, purified by distillation.
Selenium GOST 10298.
Solutions of known concentration of selenium.
The solution And the mass concentration of selenium 0.001 g/cm3: in a beaker or conical flask with a capacity of 100 cm3 is placed a suspension of selenium mass 0,1000 g, pour 10 — 15 cm3 of nitric acid, diluted 1:1, dissolved in a water bath at a temperature of 60 — 70 °C, evaporated to a volume of 1 — 2 cm3, pour 20 cm3 of hydrochloric acid, heat to dissolve the salt, cooled, the solution was transferred into a measuring flask with volume capacity of 1000 cm3 and topped to the mark with water.
Solution B is the mass concentration of selenium 0,00001 g/cm3: in a volumetric flask with a capacity of 500 cm3 taken 5 cm3 of solution A and pour to the mark with hydrochloric acid diluted 1:4.
Solution of mass concentration of selenium 0,000001 g/cm3: in a volumetric flask with a capacity of 100 cm3 is taken 10 cm3 of a solution and topped up to the mark with water.
4.3 Preparation for analysis
To build a calibration curve in glasses with a capacity of 250 cm3 taken 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 cm3 solution, dilute with water to 50 cm3, pour 1.0 cm3 of formic acid, 0.5 cm3 of the solution Trilon B and then received, as specified in 4.4.
The mass of selenium in solutions for calibration curve is 0,000001; 0,000002; 0,000004; 0,000006; 0,000008; 0,000010 G.
The light absorption values of solutions and their corresponding masses selenium build the calibration graph, given the values of the light absorption of the solution prepared without the introduction of the solution of selenium.
4.4 analysis
In a beaker or conical flask with a capacity of 250 cm3 place the weighed sample mass in accordance with table 1.
Table 1 Conditions of preparation of sample solution
| Mass fraction of selenium, % | The weight of the portion of the sample, g | The volume aliquote part of the solution, cm3 |
| From 0.0001 to 0.0005 to incl. | 2,000 | 50 |
| SV. Of 0.0005 «0,0010 « | 2,000 | 25 |
| «0,0010» 0,0020 « | 1,000 | 25 |
| «0,0020» 0,0050 « | 1,000 | 10 |
The sample is dissolved by heating in 30 — 40 cm3 of nitric acid, diluted 1:1, evaporated to a solution volume of 7 — 10 cm3. After cooling, pour 10 cm3 of perchloric acid and evaporated to release vapors of perchloric acid. The residue is cooled, wash the side of the Cup with water and again evaporated to release vapors of perchloric acid. The residue is cooled, poured 5 cm3 of hydrochloric acid, diluted 1:2, heated in a water bath for 10 min, pour 15 — 20 cm3 of water and heated to dissolve the salts. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm3 and topped to the mark with water.
In a glass with a capacity of 250 cm3 taken aliquot part of the solution in accordance with table 1, dilute with water to 50 cm3, pour 1.0 cm3 of formic acid, 0.5 cm3 of the solution Trilon B, and add dropwise ammonia, diluted 1:1, to obtain a pH in the range of 0.9 and 1.1 at pH-meter.
The solution was transferred to a separatory funnel with a capacity of 100 cm3, pour 3 cm3 of the solution on-phenylendiamine, kept for 20 min, injected 6.0 cm3 of toluene, and shake the funnel with solution 2 min After phase separation, the organic layer is drained into a test tube and close the glass stopper.
After 2 h, measure the light absorption of the solution on the spectrophotometer at a wavelength of 330 nm or photoelectrocolorimeter at a wavelength range of 320 — 340 nm, using a solution of toluene and comparison cuvettes with a thickness of absorbing layer 1 cm.
The mass of selenium in the sample solution found by the calibration schedule.
4.5 Processing the analysis results
Mass fraction of selenium in the sample of X %, is calculated by the formula
(1)
where Mx is the mass of selenium in the sample solution, g;
Mto — weight of selenium in solution in the reference experiment, g;
M — the weight of the portion of the sample, g;
K — dilution factor of sample solution.
4.6 accuracy Control analysis
Control of metrological characteristics of the results of the analysis carried out according to GOST 13047.1.
Standards monitoring and error analysis method listed in table 2.
Table 2 — Standards for monitoring and error analysis method
Percentage
| Mass fraction of selenium | The permissible discrepancy between two parallel definitions d2 | Permissible discrepancies in the results of three parallel measurements d3 | The allowable discrepancy of the two results of analysis D | The error analysis method D |
| 0,00010 | 0,00004 | 0,00005 | 0,00007 | 0,00005 |
| 0,00030 | 0,00008 | 0,00010 | 0,00015 | 0,00010 |
| 0,00050 | 0,00012 | 0,00015 | 0,00020 | 0,00015 |
| 0,00100 | 0,00015 | 0,00020 | 0,00030 | 0,00020 |
| 0,0030 | 0,0004 | 0,0005 | 0,0008 | About 0.0006 |
| 0,0050 | 0,0007 | 0,0008 | 0,0014 | 0,0010 |
5 Atomic absorption method
5.1 Method of analysis
The method is based on measuring absorption at a wavelength of 196,0 nm resonance radiation by atoms of selenium generated by the electrothermal atomization of the sample solution.
5.2 measurement Means, auxiliary devices, materials, reagents, solutions
Atomic absorption spectrophotometer measurements with electrothermal atomization, the correction non-selective absorption and the automated flow of the solution into the atomizer.
Lamp hollow cathode or electrodeless discharge lamp for excitation of spectral lines of selenium.
A graphite cuvette with a pyrolytic coating prepared according
Argon gas according to GOST 10157.
Filters obestochennye in [3] or other medium density.
Nitric acid according to GOST 4461, if necessary, purified by distillation, or according to GOST 11125, diluted 1:1, 1:9, 1:19.
Hydrofluoric acid according to GOST 10484.
Nickel powder according to GOST 9722 or standard sample of Nickel with the prescribed mass fraction of selenium not more than 0.0001%.
Tantalum [4].
A solution of tantalum mass concentration of 0.001 g/cm3: in a Cup made of PTFE or glassy carbon is placed a portion of the tantalum weight 0,100 g, pour 10 cm3 of hydrofluoric acid, 0.5 — 1.0 cm3 of nitric acid, dissolve by heating, the solution was cooled, diluted with water to 100 cm3 and stored in a plastic container.
Selenium GOST 10298.
Solutions of known concentration of selenium.
The solution And the mass concentration of selenium 0.0001 g/cm3: in a glass or flask with a capacity of 100 cm3 is placed a suspension of selenium mass 0,1000 g, pour 10 — 15 cm3 of nitric acid, diluted 1:1, dissolved in a water bath at a temperature of 60 — 70 °C, cooled, the solution was transferred into a measuring flask with volume capacity of 1000 cm3, flow of 50 cm3 of nitric acid, diluted 1:1, and topped to the mark with water.
Solution B is the mass concentration of selenium 0,00001 g/cm3: in a volumetric flask with a capacity of 100 cm3 is taken 10 cm3 of solution A, pour 10 cm3 of nitric acid, diluted 1:1, and topped to the mark with water.
Solution of mass concentration of selenium 0,000001 g/cm3: in a volumetric flask with a capacity of 100 cm3 is taken 10 cm3 of a solution, pour 10 cm3 of nitric acid, diluted 1:1, and topped to the mark with water.
5.3 Preparation for assay
5.3.1 Preparation of the graphite cuvette
Graphite cell with a pyrolytic coating is placed in electrothermal atomizer atomic absorption spectrophotometer and injected into it a solution of the tantalum in a dosing volume of 0.05 cm3, and the use of the aerosol dispenser — at the time of spraying at least 50 C. the Recommended operating conditions of the atomizer shown in table 3.
Table 3 — operating conditions of the atomizer
| The name of the stage | Temperature, °C | Time |
| Drying | 150 — 160 | 2 — 20 |
| Ashing | 1000 — 1600 | 15 — 20 |
| Atomization | 2400 — 2600 | 4 — 5 |
The introduction of a solution of tantalum and the atomization is carried out at least ten times.
Prepared graphite cuvette is used repeatedly for measurements in accordance with 5.4.
5.3.2 Preparation of solutions for calibration
5.3.2.1 For calibration chart 1 in determining the mass fraction of selenium not more than 0,0010% in beakers or flasks with a capacity of 250 cm3 place hitch weight 1,000 g sample of Nickel powder or standard sample of Nickel with the prescribed mass fraction of selenium. The number of batches must match the number of points of calibration curve, including Supervisory experience.
The sample is dissolved by heating in 15 — 20 cm3 of nitric acid, diluted 1:1, boiled for 2 — 3 minutes When using Nickel powder in the solutions were filtered through filters (red or white ribbon), washed 2 — 3 times with nitric acid, diluted 1:9, the filters are washed 2 — 3 times with hot water. The solutions were evaporated to a volume of 5 — 7 cm3, flow 40 — 50 cm3 of water, heated to boiling, cooled and transferred to volumetric flasks with a capacity of 100 cm3.
In the flask is taken 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 cm3 of the solution in the flask with the solution in the reference experiment selenium solution is not administered, made up to the mark with water and measure the absorbance as indicated in 5.4.
The mass of selenium in solutions for the calibration is 0,000001; 0,000002; 0,000004; 0,000006; 0,000008; 0,000010 G.
5.3.2.2 For calibration curve 2, when determining the mass fraction of selenium more than 0,0010% in volumetric flasks with a capacity of 100 cm3 is taken in 20 cm3 of a solution in the reference experiment, prepared as described
The mass of selenium in solutions for the calibration specified
5.4 analysis
In a glass or flask with a capacity of 250 cm3 place the weighed sample mass of 1,000 g, pour 15 — 20 cm3 of nitric acid, diluted 1:1, dissolve while heating, evaporate to a volume of 5 — 7 cm3, transfer the solution into volumetric flask with a capacity of 100 cm3, cooled, made up to the mark with water.
For the mass concentration of selenium more than 0,0010% in a volumetric flask with a capacity of 100 cm3 is taken aliquot part of the solution of volume 20 cm3, made up to the mark with nitric acid, diluted 1:19.
Measure the absorbance of the sample solution and respective solutions for calibration at a wavelength of 196,0 nm, slit width is not more than 2.0 nm with the correction non-selective absorption in the current of argon at least two times, sequentially inserting them into the atomizer. Depending on the type of spectrophotometer select the optimal amount of solution injected into the atomizer, from 0.010 to 0.050 cm3 or the optimum time for spraying is from 5 to 50 C. wash the system with water, check the zero point and the stability of the calibration curve. To check the zero point solution is used, the appropriate control experience, prepared as described
Selection of optimal temperature regimes for the atomizer is carried out individually for the used spectrophotometer on solutions for calibration. Recommended operating conditions of the atomizer shown in table 4.
Table 4 — operating conditions of the atomizer
| The name of the stage | Temperature, °C | Time |
| Drying | 150 — 160 | 2 — 20 |
| Ashing | 600 — 900 | 10 — 20 |
| Atomization | 2200 — 2300 | 4 — 5 |
The values of absorption solutions for the calibration and their corresponding masses selenium build calibration graphs.
The value of absorbance of sample solution find the mass of selenium on the appropriate calibration schedule.
5.5 Processing of analysis results
Mass fraction of selenium in the sample of X %, is calculated by the formula
(2)
where Mx is the mass of selenium in the sample solution, g;
K — dilution factor of sample solution;
M — the weight of the portion of the sample,
5.6 Control of accuracy of analysis
Control of metrological characteristics of the results of the analysis carried out according to GOST 13047.1.
Standards monitoring and error analysis method listed in table 2.
