GOST 18385.0-89
GOST 18385.0−89 Niobium. General requirements for methods of analysis
GOST 18385.0−89
Group B59
STATE STANDARD OF THE USSR
NIOBIUM
General requirements for methods of analysis
Niobium. General requirements for methods of analysis
AXTU 1709
Valid from 01.01.91
before 01.01.96*
_______________________________
* Expiration removed
Protocol 5−94 N Interstate Council
for standardization, Metrology and certification
(IUS N 11/12, 1994). — Note the manufacturer’s database.
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR
DEVELOPERS
A. V. Elyutin, Yu. A. Karpov, L. N. Filimonov, E. S. Blinov, A. S. Terekhov
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from
3. REPLACE GOST 18385.0−79
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Item number |
| GOST 8.315−78 |
1.20 |
| GOST 12.0.004−79 |
2.5 |
| GOST 12.1.004−85 |
2.4 |
| GOST 6563−75 |
1.6 |
| GOST 6709−72 |
1.7 |
| GOST 9147−80 |
1.6 |
| GOST 13718−68 |
1.2 |
| GOST 14919−83 |
1.5 |
| GOST 19908−80 |
1.6 |
| GOST 20292−74 |
1.6 |
| GOST 22720.0−77 |
1.24 |
| GOST 22720.1−77 |
1.24 |
| GOST 22720.3−77 |
1.24 |
| GOST 22720.4−77 |
1.24 |
| GOST 24104−88 |
1.1 |
| GOST 25336−82 |
1.6 |
This standard establishes General requirements for methods of analysis of niobium.
1. GENERAL REQUIREMENTS
1.1. Sampling is carried out according to normative-technical documentation for specific products.
1.2. For weighing test portions used analytical laboratory scales according to GOST 24104*, torsion scales according to GOST 13718, technical scales according to normative-technical documentation.
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* On the territory of the Russian Federation GOST 24104−2001. — Note the manufacturer’s database.
1.3. Sample analyze samples and material used for sample preparation and comparison of standard solutions weighed on an analytical balance (the result of weighing is recorded with precision to the fourth decimal place).
Sample analyze samples during atomic absorption and spectral analysis are weighed on an analytical balance or a torsion balance (the result of weighing is recorded with accuracy to the third decimal place).
Attachment of reagents to prepare the developer and fixer, and floodplains weighed on technical scales (the weighing result is recorded with the accuracy to the first decimal place).
1.4. For calcining and fusing used laboratory muffle furnace MP-2УМ, PM-8, or equivalent, providing heating temperature up to 1000 °C.
1.5. For heating use electric cooker with a sealed coil according to GOST 14919или similar.
1.6. For analysis using volumetric glassware below the second accuracy class according to GOST 20292* (burettes, pipettes, cylinders, beakers, flasks) and glassware according to GOST 25336 (beakers, conical flasks, conical funnel, etc.), crockery and equipment according to GOST 9147 (crucibles, etc.), dishes made of transparent quartz GOST 19908** (crucibles, flasks, etc.), platinum Cup according to GOST 6563.
______________
* On the territory of the Russian Federation there are 29169−91 GOST, GOST 29227−91−29229−91 GOST, GOST 29251−91-GOST 29253;
** On the territory of the Russian Federation GOST 19908−90. — Note the manufacturer’s database.
1.7. For the preparation of solutions and tests used distilled water according to GOST 6709, deionized water and reagents qualification not lower than h. d. a., unless other qualifications.
1.8. Allowed the use of other equipment, materials, utensils and reagents, subject to obtaining the metrological characteristics are not inferior to those specified in relevant standards on methods of analysis.
1.9. In the expression «diluted 1:1, 1:2, etc.» the first digits represent the volumetric part of concentrated acid, or any solution, the second volume of the water.
1.10. The numerical value of the result of the analysis must end with the same number of discharges, and the corresponding value of acceptable divergence.
1.11. Preparation of solutions and analysis after each addition of the reagent the solution was stirred.
1.12. Allowed preparation of samples of comparison for the spectral analysis with the use of other quantities of the mixed substances by storing values of the mass fraction specified in the relevant standard.
1.13. When photometric and extraction-photometric definitions build the calibration graphs, the x-axis of which lay the mass of the element in micrograms, and on the y-axis — averaged values of the optical densities of the corresponding solutions, which find during the procedure of solution preparation for the construction of calibration curve and by measuring their optical densities at least three times.
When construction of calibration curve and analysis use the same reagents and solutions. Along with the samples to check the calibration graph by repeating the procedure of its construction.
The method and the conditions for constructing a calibration curve specified in the relevant standard methods of analysis.
1.14. When photometric definitions it is allowed to use the calibration factors, if pre-installed, for specific conditions of the analysis (this method, this apparatus and this interval of mass fraction) of the calibration graph is rectilinear over the whole range of concentrations.
For each defined element of the calibration factor () is determined by several (at least three) standard photometrically solutions. The mass of the element in its standard fotometricheskogo solution should be equal to the mass of the element in the volume of the analyzed solution fotometricheskogo or exceed not more than 1.2 times, or less than not more than 1.2 times.
The calibration factor () for each fotometricheskogo standard solution of the element is calculated by the formula
where is the mass of the element to
-m fotometriya standard solution, µg;
— optical density of
solution with the mass of the element
.
All the obtained values of the calibration factor to find the arithmetic mean (
)
where is the number of standard photometrically solutions.
1.15. For the final results for the photometric and extraction-photometric analyses take the arithmetic mean of two parallel definitions, each of which is made of a separate hinge.
1.16. The conditions for obtaining the calibration parameters for spectral and atomic absorption methods specified in the relevant standard methods of analysis.
1.17. The final result for the spectral analysis be the arithmetic mean of results of three parallel measurements.
1.18. In standard methods of analysis are given (in tables) permitted discrepancies for several values of the mass fraction of the element. Allowable differences for intermediate values of the mass fraction of the element are calculated by using linear interpolation.
1.19. The analysis is repeated if the difference between the results of parallel measurements exceeds the value permissible discrepancies.
1.20. The accuracy of analysis results control using standard samples of composition, in which the certified value of the mass fraction of each of the designated components differs from the mass fraction of the same component in the sample not more than two times.
The analysis is performed correctly, if the difference of the analysis result and the certified value does not exceed the permissible differences given in the relevant standard.
Use industry-standard samples of enterprises certified in accordance with GOST 8.315.
In the absence of standard samples used in the methods of control specified in the relevant standard methods of analysis.
Allowed to control the accuracy of the results by comparison with results obtained by other (control) methods.
Discrepancies of the analysis results obtained by the two methods at confidence probability of 0.95 does not exceed the value (
) calculated by the formula
where — the permissible discrepancy of the two results of the analysis obtained by the first method;
— the permissible discrepancy of the two results of the analysis obtained by the second method.
1.21. Check the accuracy of the analysis carried out in accordance with the requirements given in the methodology at least once per month and at least 
is the number of samples this grade of niobium, were analyzed for the month using the same reagents, solutions, equipment.
1.22. Allowed the use of other validated methods of analysis that are not inferior in accuracy to the methods specified in this standard.
The differences in the assessment of the quality of niobium determination is carried out according to the method specified in this standard.
1.23. The determination of oxygen, hydrogen, nitrogen and carbon is carried out according to GOST 22720.0 — GOST 22720.4.
2. SAFETY REQUIREMENTS
2.1. Niobium and its compounds in air of working zone does not produce toxic substances and belong to the fourth class of danger.
2.2. Laboratory spaces where chemicals are treated in batches of niobium must be equipped with ventilation systems according to GOST
2.3. When you use gases in cylinders must comply with the safety requirements in accordance with the rules for design and safe operation of vessels working under pressure, approved by Gosgortekhnadzor of the USSR.
2.4. Fire safety laboratory spaces shall be provided in accordance with the requirements of GOST 12.1.004*.
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* On the territory of the Russian Federation GOST 12.1.004−91. — Note the manufacturer’s database.
2.5. To work in the analytical laboratory should be allowed persons who have been duly instructed in accordance with GOST 12.0.004*.
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* On the territory of the Russian Federation GOST 12.0.004−90. — Note the manufacturer’s database.
