GOST 13047.20-2002
NICKEL. COBALT
METHOD FOR DETERMINATION OF MAGNESIUM
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 13047.20−2002 introduced directly as state standard of the Russian Federation from July 1, 2003
4 REPLACE GOST 13047.17−81, GOST 741.15−80
The CONTENTS
1 Scope 2 Normative references 3 General requirements and safety requirements 4 Atomic absorption 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 Annex A Bibliography |
GOST 13047.20−2002
INTERSTATE STANDARD
NICKEL. COBALT
Method for determination of magnesium
Nickel. Cobalt.
Method for determination of magnesium
Date of introduction 2003−07−01
1 Scope
This standard establishes the atomic absorption method for the determination of magnesium with a mass fraction of from 0.0002% 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 804−93 primary Magnesium ingots. Specifications
GOST 849−97 Nickel primary. Specifications
GOST 4461−77 nitric Acid. Specifications
GOST 4526−75 Magnesium oxide. Specifications
GOST 5457−75 Acetylene, dissolved and gaseous. Specifications
GOST 9722−97 Nickel Powder. Specifications
GOST 11125−84 nitric Acid of high purity. Specifications
GOST 13047.1−2002 Nickel. Cobalt. General requirements for methods of analysis
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
4.1 Method of analysis
The method is based on measuring absorption at a wavelength of RUB 285.2 nm resonance radiation by atoms of magnesium, formed as a result of atomization upon introduction of the sample solution into the flame acetylene-air.
4.2 measuring instruments, 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 magnesium.
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 or 1:19.
Nickel powder according to GOST 9722 or standard sample of Nickel with the prescribed mass fraction of magnesium is not more than 0,0002%.
Cobalt GOST 123 or standard sample of cobalt-installed with a mass fraction of magnesium is not more than 0,0002%.
Magnesium primary GOST 804.
Magnesium oxide according to GOST 4526, calcined at a temperature of 850 — 900 °C for 1 h.
Solutions of known magnesium concentration.
The solution And the mass concentration of magnesium 0.0001 g/cm3 magnesium: a portion of the magnesium mass 0,1000 g were placed in a glass or flask with a capacity of 100 cm3, dissolved in 15 — 20 cm3 of nitric acid, diluted 1:1, priliva it in portions of 2 — 3 cm3, boil a solution of 2 — 3 min, cooled, transferred into a measuring flask with volume capacity of 1000 cm3, made up to the mark with water.
The solution And the mass concentration of magnesium 0.0001 g/cm3 oxide magnesium: a portion of the magnesium oxide mass 0,1658 g were placed in a glass or flask with a capacity of 100 cm3, dissolved in 15 — 20 cm3 of nitric acid, diluted 1:1, boil a solution of 2 — 3 min, cooled, transferred into a measuring flask with volume capacity of 1000 cm3, made up to the mark with water.
The solution Used mass of magnesium concentration 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.
4.3 Preparation for analysis
4.3.1 For calibration chart 1 in determining the mass fraction of magnesium of not more than 0,0010% in beakers or flasks with a capacity of 250 cm3 place hitch weight 3,000 g sample of Nickel powder or cobalt or of a standard sample of composition of Nickel and cobalt to the prescribed mass fraction of magnesium. The number of batches must match the number of points of calibration curve, including Supervisory experience.
The sample flow 40 — 50 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 15 — 20 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; 3,0; 4,0 cm3 of solution B in the flask with the solution in the reference experiment, a solution of magnesium are administered, made up to the mark with water and measure the absorbance as indicated in 4.4.
Mass of magnesium in solutions for the calibration is 0,000005; 0,000010; 0,000020; 0,000030; 0,000040 G.
4.3.2 For calibration curve 2, when determining the mass fraction of magnesium of 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 specified in 4.3.1, enter 0,5; 1,0; 2,0; 3,0; 4,0 cm3 of solution B into one of the flasks with a solution of the reference experiment, a solution of magnesium are administered, made up to the mark with nitric acid, diluted 1:19, and measure the absorbance as indicated in 4.4.
Mass of magnesium in solutions for the calibration specified
4.4 analysis
In a glass or flask with a capacity of 250 cm3 place the weighed sample mass of 3,000 g, poured 40 — 50 cm3 of nitric acid, diluted 1:1, dissolve while heating, evaporate to a volume of 15 — 20 cm3, transfer the solution into volumetric flask with a capacity of 100 cm3, cooled, made up to the mark with water.
When the mass fraction of magnesium of 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 and the corresponding solutions for the calibration at a wavelength of RUB 285.2 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 solution is used, the appropriate control experience, prepared as described in section 4.3.
The values of absorption solutions for the calibration and corresponding mass of magnesium to build the calibration graph.
The value of absorbance of sample solution find the mass of magnesium on the appropriate calibration schedule.
4.5 Processing the analysis results
Mass fraction of magnesium in the sample of X %, is calculated by the formula
(1)
where Mx is the mass of magnesium in the sample solution, g;
K — dilution factor of sample solution;
M — the weight of the portion of the sample,
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 1.
Table 1 — Standards for monitoring and error analysis method
Percentage
| Mass fraction of magnesium | 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 |
| 0,00020 | 0,00004 | 0,00005 | 0,00008 | Of 0.00006 |
| 0,00030 | 0,00005 | Of 0.00006 | 0,00010 | 0,00007 |
| 0,00050 | 0,00007 | 0,00008 | 0,00014 | 0,00010 |
| 0,00100 | 0,00010 | 0,00012 | 0,00020 | 0,00015 |
| 0,0030 | 0,0003 | 0,0004 | 0,0007 | 0,0005 |
