GOST 12550.1-82
GOST 12550.1−82 Alloys palladium-iridium. Method of determining palladium (with Change No. 1)
GOST 12550.1−82
Group B59
INTERSTATE STANDARD
ALLOYS OF PALLADIUM AND IRIDIUM
Method for the determination of palladium
Palladium-iridium alloys. Method for the determination of palladium
AXTU 1709
Date of introduction 1984−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
A. A. Kuranov, PhD. tech. science; N.And.Timofeyev, Cand. tech. Sciences; G. S. Haak; N. With. Stepanova, N. D. Sergienko, PhD. chem. Sciences; A. A. Osintseva; T. I. Belyaev; E. E. Safonova
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. REPLACE GOST 12550−67 in section 2
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
The designation of the reference document referenced |
Section number, paragraph |
GOST 199−78 |
2 |
GOST 3118−77 |
2 |
GOST 4461−77 |
2 |
GOST 5823−78 |
2 |
GOST 10652−73 |
2 |
GOST 13462−79 |
2 |
GOST 22864−83 |
1.1 |
5. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
6. The re-release (December 1998) with amendment No. 1, approved in April 1988 (I & C 7−88)
This standard specifies the titrimetric method for the determination of palladium in palladium-iridium alloys (mass fraction of palladium at from 50 to 92%).
The method is based on the binding of a palladium complex compound dwuzameshchenny the sodium salt of ethylenediaminetetraacetic acid (Trilon B) at pH 5−5,5 and titrate the excess Trilon B with a solution of acetate of zinc with indicator kylinalove orange.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 22864.
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. REAGENTS AND SOLUTIONS
Hydrochloric acid according to GOST 3118.
Nitric acid according to GOST 4461.
Mixture of nitric and hydrochloric acids in a ratio of 1:3.
Sodium acetate 3-water according to GOST 199, a solution with a mass fraction of 50%.
Salt is the disodium Ethylenediamine-N,N,N',N'-tetraoxane acid, 2-water (Trilon B) according to GOST 10652, a 0.75 M solution of 27.9 g of salt is dissolved by heating in 500 cmof water and bring the volume to 1000 cmwater.
Zinc acetate 2-water according to GOST 5823, 0.1 M solution of 9.15 g of salt is dissolved by heating in 500 cmof water and bring to 1000 cmwater.
Selenology orange indicator solution with a mass fraction of 0.2%.
Palladium brand PD 99,9 GOST 13462, standard solution: 5,0000 g of palladium was dissolved with heating in 30 cmof a mixture of acids, was transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.
1 cmof the solution contains 0.01 g of palladium.
Determine the ratio of the volume of the solution Trilon B and zinc acetate: a pipette or a burette you take 10 cmof the solution Trilon B, is placed in a conical flask with a capacity of 250 cm, flow 20 cmwater, 5 cmof a solution of sodium acetate, 10 drops of the indicator solution kylinalove orange and titrated with a solution of zinc acetate until the color changes from yellow to crimson. At the same time three definitions.
The volume ratio () is calculated by the formula
,
where is the volume of solution of acetate of zinc, used for titration of 10 cmsolution of Trilon B, cm.
Determination of the titer of 0.15 n solution of Trilon B by palladium: 20 cmstandard solution palladium was placed in a conical flask with a capacity of 250 cm, poured with a pipette or a burette 40 cmof the solution Trilon B, 30 cmwater, 10 cmof a solution of sodium acetate, 10 drops of indicator solution and titrated with a solution of zinc acetate until the color of solution from yellow to bright red.
The titer of the solution Trilon B () at the palladium, expressed in g/cm, is calculated by the formula
,
where is the mass of palladium contained in 20 cmstandard solution, g;
— volume of solution Trilon B, cm;
— the volume of solution of acetate of zinc, consumed in the titration of excess Trilon B, cm;
— the ratio of the volume of the solution Trilon B and zinc acetate.
(Changed edition, Rev. N 1).
3. ANALYSIS
A portion of the alloy with a mass of 0.25 g is placed in a conical flask with a capacity of 250 cm, was dissolved with heating in 30 cmof a mixture of acids, is evaporated to 5 cmand cooled to room temperature. Then pour a pipette or a burette 40 cmTrilon B, 40 cmof a solution of sodium acetate and mix thoroughly. Excess Trilon B octarepeat solution of acetate of zinc in the presence of an indicator kylinalove orange (10 drops) until the color of solution from yellow to bright red.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of palladium () in percent is calculated by the formula
,
where — the volume of Trilon B added for education complex of palladium, cm;
— the volume of solution of acetate of zinc, consumed in the titration of excess Trilon B, cm;
— the ratio of the volume of the solution Trilon B, and acetate of zinc;
the titer of the solution Trilon B at the palladium, g/cm;
— the mass of alloy,
G.
4.2. Allowable absolute discrepancies in the results of parallel measurements (the rate of convergence) at a confidence probability of 0.95, should not exceed 0.30 percent.
Absolute differences average results of determinations obtained in two different laboratories (a measure of reproducibility) shall not exceed 0,50%.
(Changed edition, Rev. N 1).
4.3. Control of accuracy of analysis results.
Accuracy control in the determination of the mass fraction of palladium is playing its mass fraction in the artificial mixtures the chemical composition close to the chemical composition of the analyzed alloy, drawn through the entire course of the analysis.
The results of the analysis of samples believed to be accurate, if the absolute difference between the maximum and minimum values of the mass fraction of palladium in the synthetic mixtures does not exceed 0,14% when the mass fraction of palladium from 50 to 83% and 0.15% when the mass fraction of palladium of more than 83%.
(Added, Rev. N 1).