GOST 13047.16-2002
NICKEL. COBALT
METHODS FOR DETERMINATION OF CADMIUM
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 13047.16−2002 introduced directly as state standard of the Russian Federation from July 1, 2003
4 REPLACE GOST 13047.13−81, GOST 741.14−80
GOST 13047.16−2002
INTERSTATE STANDARD
NICKEL. COBALT
Methods for determination of cadmium
Nickel. Cobalt.
Methods for determination of cadmium
Date of introduction 2002−07−01
1 Scope
This standard establishes the atomic absorption methods for the determination of cadmium with mass fraction of from 0.00001% to 0,0030% in primary Nickel GOST 849, Nickel powder according to GOST 9722 and GOST cobalt 123 on.
2 Normative references
The present standard features references to the following standards:
GOST 123−98 Cobalt. Specifications
GOST 849−97 Nickel primary. Specifications
GOST 1467−93 Cadmium. Specifications
GOST 4461−77 nitric Acid. Specifications
GOST 5457−75 Acetylene, dissolved and gaseous. Specifications
GOST 9722−97 Nickel Powder. Specifications
GOST 10157−79 Argon gaseous and liquid. Specifications
GOST 11125−84 nitric Acid of high purity. Specifications
GOST 13047.1−2002 Nickel. Cobalt. General requirements for methods of analysis
GOST 22860−93 Cadmium 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 Atomic absorption method with electrothermal atomization
4.1 Method of analysis
The method is based on measuring absorption at a wavelength of 228,8 nm resonance radiation by atoms of cadmium resulting from the electrothermal atomization of the sample solution.
4.2 measuring instruments, 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 with hollow cathode for the excitation of spectral lines of cadmium.
Argon gas according to GOST 10157.
Filters obestochennye [1] 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 and 1:19.
Nickel powder according to GOST 9722 or standard sample of Nickel with the prescribed mass fraction of cadmium, not more than 0,00001%.
Cobalt GOST 123 or standard sample of cobalt with the prescribed mass fraction of cadmium, not more than 0,00001%,
Cadmium GOST 1467 or GOST 22860.
Cadmium solutions of known concentration.
The solution And the mass concentration of cadmium 0.0001 g/cm3: in a glass with a capacity of 250 cm3 is placed a portion of the cadmium mass 0,1000 g, was dissolved with heating in 15 — 20 cm3 of nitric acid, diluted 1:1, boil the solution for 3 to 5 minutes, cooled, 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 mass concentration of cadmium 0,00001 g/cm3: in a volumetric flask with a capacity of 100 cm3 is taken 10 cm3 of solution A and pour to the mark with nitric acid, diluted 1:19.
Solution of the mass concentration of cadmium 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 nitric acid, diluted 1:19.
The solution G of the mass concentration of cadmium 0,0000002 g/cm3: in a volumetric flask with a capacity of 100 cm3 is taken in 20 cm3 of solution and topped up to the mark with nitric acid, diluted 1:19.
4.3 Preparation for analysis
4.3.1 For calibration chart 1 in determining the mass fraction of cadmium not more than 0,00010% in beakers or flasks with a capacity of 250 cm3 put the hitch weight 1,000 g sample of Nickel powder or cobalt, or a standard sample of Nickel or cobalt with the prescribed mass fraction of cadmium. The number of batches must match the number of points of calibration curve, including Supervisory experience.
The sample flow 15 — 20 cm3 of nitric acid, diluted 1:1 and dissolved by heating. When using the 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 water. The solutions were evaporated to a volume of 5 — 7 cm3, flow 40 — 50 cm3 of water, heated to boiling, cooled, transferred to volumetric flasks with a capacity of 100 cm3.
In the flask is taken 0,5; 1,0; 2,0; 4,0; 5,0 cm3 of solution G in the flask with the solution in the reference experiment, a solution of cadmium do not enter, made up to the mark with water and measure the absorbance as indicated in 4.4.
The mass of cadmium in solutions for calibration curve 1 is of 0.0000001; 0,0000002; 0,0000004; 0,0000008; 0,0000010 G.
4.3.2 For calibration curve 2, when determining the mass fraction of cadmium more than 0,00010% in beakers or flasks with a capacity of 250 cm3 place the sample weighing 0,500 g sample of Nickel powder or cobalt, or a standard sample of Nickel or cobalt with the prescribed mass fraction of cadmium. The number of batches must match the number of points of calibration curve, including Supervisory experience.
The sample is dissolved as specified
The mass of cadmium in solutions for calibration curve 2 is 0,0000005; 0,0000010; 0,0000020; 0,0000030; 0,0000040; 0,0000050; 0,0000060 G.
4.4 analysis
In a glass or flask with a capacity of 250 cm3 place the weighed sample mass of 1,000 g in determining the mass fraction of cadmium not more than 0,00010% or weighing 0,500 g in the determination of mass fraction of cadmium more than 0,00010%, pour 15 — 20 cm3 of nitric acid, diluted 1:1, evaporated to a volume of 5 — 7 cm3, transfer the solution into volumetric flask with a capacity of 100 cm3, cooled and topped to the mark with water.
Measure the absorbance of the sample solution and respective solutions for calibration at a wavelength of 228,8 nm, slit width is not more than 1.0 nm with a 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 volume of the solution from 0.005 to 0.050 cm3 or the optimal time of an aerosol spray 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 in section 4.3.
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 1.
Table 1 — operating conditions of the atomizer
| The name of the stage | Temperature, °C | Time |
| Drying | 140 — 160 | 2 — 20 |
| Ashing | 400 — 500 | 10 — 20 |
| Atomization | 1800 — 2000 | 4 — 5 |
The values of absorption solutions for the calibration and corresponding masses of cadmium build the calibration graph.
The value of absorbance of sample solution find the mass of cadmium for the corresponding calibration chart.
4.5 Processing the analysis results
Mass fraction of cadmium in the sample of X %, is calculated by the formula
(1)
where Mxis the mass of cadmium in the sample solution, g;
M — weight of sample, g.
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 are given in table 2.
Table 2 — Standards for monitoring and error analysis method
Percentage
| Mass fraction of cadmium in | 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 |
| 0,000010 | 0,000004 | 0,000005 | 0,000008 | 0,000006 |
| 0,000030 | 0,000010 | 0,000012 | 0,000020 | 0,000014 |
| 0,000050 | 0,000020 | 0,000024 | 0,000040 | 0,000028 |
| 0,00010 | 0,00003 | 0,00004 | Of 0.00006 | 0,00004 |
| 0,00030 | 0,00005 | Of 0.00006 | 0,00010 | 0,00007 |
| 0,00050 | 0,00007 | 0,00009 | 0,00014 | 0,00010 |
| 0,00100 | 0,00015 | 0,00018 | 0,00030 | 0,00021 |
| 0,00200 | 0,00020 | 0,00024 | 0,00040 | 0,00028 |
| 0,0030 | 0,0003 | 0,0004 | About 0.0006 | 0,0004 |
5 Atomic absorption method with flame atomization (mass fraction of cadmium from from 0.0002% to 0,0030%)
5.1 Method of analysis
The method is based on measuring absorption at a wavelength of 228,8 nm resonance radiation by atoms of cadmium resulting from atomization upon introduction of the sample solution into the flame acetylene-air.
5.2 measurement Means, auxiliary devices, materials, reagents, solutions
Atomic absorption spectrophotometer measurements in the flame acetylene-air.
Lamp with hollow cathode for the excitation of spectral lines of cadmium.
Acetylene gas according to GOST 5457.
Filters obestochennye [1] 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 and 1:19.
Nickel powder according to GOST 9722 or standard sample of Nickel with the prescribed mass fraction of cadmium is not more than 0,0002%.
Cobalt GOST 123 or standard sample of cobalt with the prescribed mass fraction of cadmium is not more than 0,0002%.
Cadmium GOST 1467 or GOST 22860.
Cadmium solutions of known concentration.
The solution And the mass concentration of cadmium 0.0001 g/cm3 prepared as described in 4.2.
Solution B mass concentration of cadmium 0,00001 g/cm3 prepared as described in 4.2.
5.3 Preparation for assay
For calibration curve into beakers or flasks with a capacity of 250 cm3 place hitch weight 3,000 g sample of Nickel powder or cobalt, or a standard sample of Nickel or cobalt with the prescribed mass fraction of cadmium. The number of batches must match the number of points of calibration curve, including Supervisory experience.
Sample poured to 25 — 30 cm3 of nitric acid, diluted 1:1 and dissolved by heating. When using the 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 10 — 15 cm3, flow 40 — 50 cm3 of water, heated to boiling, cooled, transferred to volumetric flasks with a capacity of 100 cm3.
In the flask is taken 0,5; 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 cm3 of solution B in the flask with the solution in the reference experiment, a solution of cadmium do not enter, made up to the mark with water and measure the absorbance as indicated in 5.4.
The mass of cadmium in solutions to calibration is 0,000005; 0,000010; 0,000020; 0,000040; 0,000060; 0,000080; 0,000100 G.
5.4 analysis
In a glass or flask with a capacity of 250 cm3 place the weighed sample mass of 3,000 g, pour 25 — 30 cm3 of nitric acid, diluted 1:1, dissolved by heating, boil for 2 — 3 min, evaporated to a volume of 15 — 20 cm3, pour water up to 50 — 60 cm3, cooled, transfer the solution into a volumetric flask with a capacity of 100 cm3, made up to the mark with water.
Measure the absorbance of the sample solution and solutions for calibration at a wavelength of 228,8 nm, slit width is not more than 1.0 nm at least two times, sequentially inserting them into a flame, wash the system with water, check the zero point and the stability of the calibration curve. To check the zero point of the solution is used in the reference experiment, prepared as described in 5.3.
The values of absorption solutions for the calibration and corresponding masses of cadmium build the calibration graph.
The value of absorbance of sample solution find the mass of cadmium in the calibration schedule.
5.5 Processing of analysis results
Mass fraction of cadmium in the sample of X %, is calculated by the formula
(2)
where Mx is the mass of cadmium in the sample solution, g;
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 are given in table 2.
