GOST 12551.1-82
GOST 12551.1−82 Alloys platinum-copper. Methods for determination of copper (with Change No. 1)
GOST 12551.1−82
Group B59
STATE STANDARD OF THE USSR
ALLOYS PLATINUM-COPPER
Methods for determination of copper
Alloys platinum-copper. Methods for the determination of copper
AXTU 1709*
______________
* Introduced advanced Edit. N 1.
Valid from 01.01.84
to 01.01.89*
________________________________
* Expiration removed by Protocol No. 3−93
The interstate Council for standardization,
Metrology and certification (ICS No. 5/6, 1993). -
Note the manufacturer’s database.
DEVELOPED by the Ministry of nonferrous metallurgy of the USSR
PERFORMERS
A. A. Kuranov, G. S. HAK, N. With. Stepanova, N. D. Sergienko, I. G., Sazhin, T. I. Belyaeva, E. B. Safonov
INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
Zam. Minister Vladimir Boroday
APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards, dated 30 September 1982, N 3866
REPLACE GOST 12551−67 in part of sec. 2
The Change N 1, approved and put into effect by the Decree of the USSR State Committee for standards from
Change No. 1 made by the manufacturer of the database in the text ICS N 7, 1988
This standard sets the photometric and atomic absorption methods for the determination of copper (at a mass fraction of copper from 2.0 to 3.0% and from 8.0 to 9.0%) in platinum-copper alloys.
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 22864−83.
(Changed edition, Rev. N 1).
1.2. The numerical value of the result of the analysis must end with a digit of the same rank as that of the normalized indicator grade composition.
(Added, Rev. N 1).
2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF COPPER
2.1. The essence of the method
The method is based on formation of colored complex of copper with ammonia, the pre-binding platinum complex in a colorless philosemitism sodium.
2.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Hydrochloric acid by the GOST 3118−77.
Nitric acid GOST 4461−77 and diluted 1:1.
Mixture of nitric and hydrochloric acids in a ratio of 1:3.
Ammonia water according to GOST 3760−79 and diluted 1:40.
Sodium sanitarily Piro, a freshly prepared solution with a mass fraction of 25%.
Platinum according to GOST 13498−79 brand of 99.9.
Copper GOST 859−78* brand Muck, M00k or M00b.
______________
* On the territory of the Russian Federalization GOST 859−2001, here and hereafter. — Note the manufacturer’s database.
Standard copper solution: 0,5000 g of copper is dissolved in 20 cmof nitric acid (1:1), heated to remove oxides of nitrogen, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.
(Changed edition, Rev. N 1).
2.3. Analysis
2.3.1. Preparation of a standard solution of alloy
The weight of platinum is placed in a beaker with a capacity of 150 cm, is dissolved by heating in 10 cmof a mixture of acids, and introduced a standard copper solution and evaporated until approximately 0.5 cm. The weight of platinum and the volume of a standard solution of copper is given in table.1.
Table 1
Mass fraction of copper, % | The weight of the portion of platinum, g |
The volume of a standard solution of copper, see |
2,5 | 0,29 |
2,5 |
8,5 | 0,09 |
8,5 |
2.3.2. Determination of copper
Samples of alloy are available for analysis in the form of thin ribbons or shavings of a thickness of 0.2 mm.
A sample of alloy weighing 0.3 g (with a mass fraction of copper from 2.0 to 3.0%) or 0.1 g (with mass fraction of copper from 8.0 to 9.0%) were placed in a glass with a capacity of 150 cm, is dissolved by heating in 20 cmof a mixture of acids and the solution evaporated to 0.5 cm.
In the analyzed and standard solutions of alloy was added 10 cmwater 10 cmsolution preservestacktrace of sodium and the solution is kept for 10 min. Then add 25 cmof water of ammonia, the solutions were cooled and filtered in a volumetric flask with a capacity of 100 cm. The filter is washed with cold ammonia solution (1:10). The solution was topped to the mark with water, mix and measure optical density of solution on a photoelectrocolorimeter with a red filter or on a spectrophotometer at a wavelength of 670 nm in cuvettes with the thickness of the light absorbing layer was 50 mm.
Solution comparison is the solution not containing platinum and copper
.
2.4. Processing of the results
2.4.1. Mass fraction of copper () in percent is calculated by the formula
,
where a — optical density of the analyzed solution;
— optical density of standard solution alloy;
— mass fraction of copper in the standard solution of the alloy, %.
2.4.2. Allowable absolute discrepancies in the results of parallel measurements (the rate of convergence) with confidence probability of 0.95 should not exceed 0.15%.
Absolute differences average results of determinations obtained in two different laboratories (a measure of reproducibility) shall not exceed 0.25%.
(Changed edition, Rev. N 1).
2.4.3. Control of accuracy of analysis results
Control the accuracy of results of determining the mass fraction of copper is carried out by the reproduction of its mass fraction in the artificial mixtures the chemical composition close to the composition of the analyzed alloy, drawn through the entire course of the analysis.
The sample analysis results are considered accurate if the absolute difference between the maximum and minimum values of the mass fraction of copper in the artificial mixture does not exceed 0.05% when the mass fraction of copper from 2.0 to 3.0% and 0.09% when the mass fraction of copper from 8.0 to 9.0%.
(Added, Rev. N 1).
3. ATOMIC ABSORPTION METHOD FOR DETERMINATION OF COPPER
3.1. The essence of the method
The method is based on measuring the absorption of light by atoms of copper with the introduction of the solution of the alloy in an air-acetylene flame.
3.2. Apparatus, reagents and solutions
Spectrophotometer atomic absorption.
Lamp with a hollow cathode emitting spectrum of copper atoms.
Hydrochloric acid by the GOST 3118−77 and a solution with a mass fraction of 3%.
Nitric acid GOST 4461−77.
Mixture of nitric and hydrochloric acids in a ratio of 1:3.
Copper GOST 859−78 brand Muck, M00k or M00b.
Standard solutions of copper.
Solution a: 0,5000 g of copper is dissolved in 10 cmof a mixture of acids, is transferred into a volumetric flask with a capacity of 500 cm, made up to the mark with hydrochloric acid with a mass fraction of 3% and stirred.
1 cmof the solution contains 1 mg of copper.
Platinum according to GOST 13498−79 brand of 99.9.
Standard solutions of platinum.
Solution a: 1,0000 g of platinum was dissolved with heating in 30 cmof the mixture of acids and evaporated to 5 cm, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with hydrochloric acid with a mass fraction of 3% and stirred.
1 cmof solution A contains 10 mg of platinum.
Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cm, made up to the mark with hydrochloric acid with a mass fraction of 3% and stirred.
1 cmof the solution contains 1 mg of platinum.
(Changed edition, Rev. N
1).
3.3. Analysis
3.3.1. A sample of alloy weighing 0.1 g were placed in a glass with a capacity of 100 cmand dissolved by heating in 20 cmof a mixture of acids. The solution was evaporated to 5 cm, transferred to volumetric flask (see table 2), made up to the mark with hydrochloric acid with a mass fraction of 3% and stirred.
Table 2
Mass fraction of copper, % | Volume volumetric flasks, cm |
The volume aliquote part, see |
From 2.0 to 3.0 |
100 | 10 |
An «8.0 «to 9.0 |
200 | 5 |
From the volumetric flask selected aliquot part (see table.2), placed in a volumetric flask with a capacity of 50 cm, made up to the mark with hydrochloric acid with a mass fraction of 3% and stirred.
At the same time in a volumetric flask with a capacity of 100 cmprepare a standard solution alloy with copper concentration of 5 mg/cmfor alloys with a mass fraction of copper from 2.0 to 3.0% or 4.25 mg/cmfor alloys with a mass fraction of copper from 8.0 to 9% copper (table.3).
Table 3
The copper content in the standard solution alloy, mg/cm |
The volume of a standard solution of copper, see |
The volume of a standard solution of platinum, cm |
5,00 |
5,00 | 19,50 |
4,25 |
4,25 | 4,60 |
Analyzed and standard solutions of alloy sprayed in air-acetylene flame atomic absorption spectrophotometer and measure the absorbance at the wavelength of 324,7 nm, installation of slit 4 (0.7 nm), lamp current of 25 mA.
The flow of air and acetylene is adjusted to maximize absorption standard solution alloy.
(Changed edition, Rev. N 1).
3.4. Handling results according to claim 2.4.
3.4.1. The method used in the dispute in the assessment of the quality of the alloys.
3.4.2. Control of the correctness of the analysis results according to claim
(Added, Rev. N 1).