GOST R 54493-2011
GOST R 54493−2011 Iridium. Rhodium. Ruthenium. Method for determination of loss on heating
GOST R 54493−2011
Group W51
NATIONAL STANDARD OF THE RUSSIAN FEDERATION
IRIDIUM. RHODIUM. RUTHENIUM
Method for determination of loss on heating
Iridium. Rhodium. Ruthenium. Method for determination of mass loss after ignition
OKS 77.120.99
Date of introduction 2012−08−01
Preface
The objectives and principles of standardization in the Russian Federation established by the Federal law of 27 December 2002 N 184-FZ «On technical regulation», and rules for the application of national standards of the Russian Federation — GOST R 1.0−2004 «Standardization in the Russian Federation. The main provisions"
Data on standard
1 DEVELOPED by the Moscow state Academy of fine chemical technology. M. V. Lomonosov (MITHT M. V. Lomonosova), a Public institution on formation of the State Fund of precious metals and precious stones of the Russian Federation, storage, holiday and use of precious metals and precious stones (Gokhran of Russia) under the Ministry of Finance of the Russian Federation
2 SUBMITTED by the Technical Committee for standardization TC 102 «Platinum metals"
3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology dated 10 November 2011 N 537-St
4 INTRODUCED FOR THE FIRST TIME
Information about the changes to this standard is published in the annually issued reference index «National standards», and the text changes and amendments — in monthly indexes published information «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in a monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet
1 Scope
This standard applies to affined iridium, rhodium, ruthenium powder with a mass fraction of base metal not less than 99.8%, designed for the production of alloys, semi-finished products and other purposes.
The standard specifies a method of determining the weight loss during calcination of refined iridium, rhodium, ruthenium powder in a mass fraction range from 0,0020% to 0.050%.
2 Normative references
This standard uses the regulatory references to the following standards:
GOST R 8.563−2009 State system for ensuring the uniformity of measurements. Techniques (methods) of measurements
GOST R ISO 5725−1-2002 Accuracy (trueness and precision) of methods and measurement results. Part 1. General provisions and definitions
GOST R ISO 5725−6-2002 Accuracy (correctness and precision) of methods and measurement results. Part 6. The use of precision values in practice
GOST R 52599−2006 Precious metals and their alloys. General requirements for methods of analysis
GOST R 53228−2008 Scales non-automatic actions. Part 1. Metrological and technical requirements. Test
GOST 3022−80 Hydrogen technical. Specifications
GOST 6563−75 technical articles made of noble metals and alloys. Specifications
GOST 8050−85 gaseous carbon Dioxide and liquid. Specifications
GOST 9147−80 Glassware and equipment lab porcelain. Specifications
GOST 25336−82 Glassware and equipment laboratory glass. The types, basic parameters and dimensions
Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet or published annually by the information sign «National standards» published as on January 1 of the current year and related information published monthly indexes published in the current year. If the reference standard is replaced (changed), when using this standard should be guided by replacing (amended) standard. If the reference standard is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.
3 Terms and definitions
This standard applies the terminology according to GOST R ISO 5725−1 and GOST R 8.563.
4 the essence of the method
The method is based on calcination of refined iridium, rhodium, ruthenium powder at a temperature of from 900 °C to 1000 °C to constant weight and determining the weight loss (difference of mass of the sample powder before and after calcination) by gravimetric method.
5 Accuracy (trueness and precision) of the method
5.1 indicators of the accuracy of the method
Indicators of accuracy of method: absolute error of the results of the analysis (assigned error) , standard deviation of repeatability
and intermediate precision
depending on the mass fraction of the mass loss on ignition are given in table 1.
Table 1 — Indicators of accuracy of the method when p = 0.95
Percentage
| The level of weight loss during calcination | The boundaries of the interval of absolute error |
The standard deviation of repeatability |
The critical range |
The standard deviation of intermediate precision |
The limit of intermediate precision |
The limit of rehabilitation |
| 0,0020 | 0,0020 |
0,0007 | 0,0025 | 0,0008 | 0,0023 | 0,0028 |
| 0,0050 | 0,0047 |
0,0017 | 0,0062 | 0,0020 | 0,0055 | 0,0066 |
| 0,020 | 0,007 |
0,002 | 0,009 | 0,003 | 0,009 | 0,010 |
| 0,050 | 0,009 |
0,003 | 0,011 | 0,004 | 0,010 | 0,012 |
For intermediate values, the mass fraction loss of mass on ignition values of accuracy find using linear interpolation according to the formula
where — the value of the index of precision for test results
, %;
,
— the value of the indicator of accuracy, corresponding to the lower and upper levels of the mass fraction of the mass loss between which is the result of the analysis, %;
— the result of the analysis, %;
,
the lower and upper levels of a mass fraction loss of mass, between which is the result of the analysis, %.
5.2 Correctness
Systematic error of the present method of analysis is not meaningful at all levels of the mass loss during annealing.
5.3 Precision
5.3.1 Range of four results (4) obtained for the same sample by one operator using the same equipment within the shortest possible time intervals may be greater than indicated in the table 1 critical range
5.3.2 within one laboratory two results of the analysis of the same sample obtained by different operators using the same equipment on different days, can vary in excess of the limit of intermediate precision 
5.3.3 Results of the analysis of the same samples, obtained in two laboratories in accordance with sections 7 and 8 may vary in excess of the limit of reproducibility indicated in table 1, on average not more than once in 20 cases with proper use of the method.
6 Requirements
6.1 General requirements and safety requirements
General requirements for method of analysis and requirements for security of works — according to GOST R 52599.
6.2 qualifications of performers
The analysis allowed persons over the age of 18, trained in the prescribed manner and allowed to work independently on used equipment.
7 measurement Means, auxiliary devices, materials and reagents
Furnace for calcination, providing a heating temperature of 1000 °C.
Laboratory scales in accordance with GOST R 53228 with a limit of permissible absolute error no more than ±0,0001 g.
Desiccator, according to GOST 25336.
Platinum crucibles N 100−7 according to GOST 6563.
Crucibles porcelain No. 4, GOST 9147.
Watch for General use.
Hydrogen technical GOST 3022 or obtained in the laboratory.
Carbon dioxide gas according to GOST 8050 or obtained in the laboratory.
Allowed the use of other measuring instruments and auxiliary devices subject to receipt of the accuracy rate that rivals those in table 1.
8 analysis
8.1 Clean platinum crucible placed in a porcelain crucible and calcined in a furnace for 10−15 minutes at a temperature of 900 °C — 1000 °C in flowing hydrogen. After calcination porcelain crucible with a platinum crucible is removed from furnace without turning off the current of hydrogen. Include current of carbon dioxide and 3−5 with shut off the current of hydrogen. Cool the crucible in a current of carbon dioxide for 5−10 min, then transfer it to the desiccator, cooled to room temperature and weighed platinum crucible with error not more than ±0,0001 g.
The operation of calcination, cooling, weigh the platinum crucible is repeated until obtaining constant weight.
Criterion bring the crucible to constant weight is the difference of the results of successive weighings not exceeding 0,0001 g.
8.2 In the same platinum crucible, brought to a constant weight, is placed from 4.5 to 5.5 g of analyzed metal and weigh the crucible with the metal with the error not more than ±0,0001 g. the crucible with the metal is placed in a porcelain crucible and calcined in a furnace at a temperature of from 900 °C to 1000 °C for 20−25 min in a current of hydrogen.
8.3 Upon completion of the calcination powder of iridium or rhodium porcelain crucible platinum crucible is removed from furnace without turning off the current of hydrogen. Include current of carbon dioxide and 3−5 with shut off the current of hydrogen. Cool the crucibles in a current of carbon dioxide to room temperature, then transfer them to the desiccator. A platinum crucible is weighed, determine the mass of the crucible with the calcined metal linkage with a tolerance no more than ±0,0001 g.
8.4 At the end of the calcination powder of ruthenium porcelain crucible platinum crucible is removed from furnace without turning off the current of hydrogen. Include current of carbon dioxide and 3−5 with shut off the current of hydrogen, to extinguish the flame, then re-include current of hydrogen. Cool platinum crucible with powder of ruthenium in a current of carbon dioxide and hydrogen to room temperature, after which it was transferred to a desiccator. A platinum crucible is weighed, determine the mass of the crucible with the calcined metal linkage with a tolerance no more than ±0,0001 g.
8.5 the Operation of calcination, cooling and weighing the crucible with metal is repeated to obtain a constant weight by reducing the time of calcination to 10−15 min. the Criterion of bringing the crucible with the metal to constant weight is the difference of the results of successive weighings not exceeding 0,0001 g.
9 Processing of results, evaluation of their acceptability and the achievement of a final result of the analysis
9.1 the mass Loss on ignition (mass fraction) , %, is calculated by the formula
where is the difference of the mass of the platinum crucible with the charge of metal before and after ignition, g;
— the weight of the portion of the metal,
9.2 the acceptability of the results of parallel measurements was evaluated in accordance with GOST R ISO 5725−6 by comparing the range of these results 
If the range of the four results of parallel measurements 
If the range of the four results of parallel measurements exceeds 
If the received eight results of parallel measurements the value 
The critical range for eight (8) results of parallel measurements
where is the number of parallel definitions;
— the ratio of the critical range, for eight parallel measurements of the coefficient is equal to 4,29;
— standard deviation of repeatability.
10 Control of accuracy of analysis results
10.1 Control of intermediate precision and reproducibility
When monitoring intermediate precision (variable factors of the operator and time) is the absolute value of the difference between two results of analysis of the same sample obtained by different operators using the same equipment on different days, should not exceed the limit of intermediate precision 
Under the control of the reproducibility of the absolute value of the difference of the two results of the analysis of the same samples, obtained in two laboratories, in accordance with the requirements of this standard must not exceed the limit of reproducibility indicated in table 1.
