GOST 8775.0-87
GOST 8775.0−87 Li. General requirements for methods of analysis
GOST 8775.0−87
Group B59
STATE STANDARD OF THE USSR
LI
General requirements for methods of analysis
Lithium.
General requirements for methods of analysis
AXTU 1709
Valid from 01.07.88
to 01.07.93*
__________________________
* Limit of validity
based on a Protocol of Intergovernmental
Council for standardization, Metrology
and certification (I & C N 2, 1993). -
Note the manufacturer’s database.
INFORMATION DATA
1. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
2. The term of the first test 1991
The frequency of inspection 5 years
3. REPLACE GOST 8775−75 (sect.1)
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Section number, paragraph |
| GOST 6709−72 |
2.2 |
| GOST 8774−75 |
1, 2.1, 2.14 |
| GOST 25086−81* |
2 |
| GOST 25336−82 |
2.3 |
________________
* Standards 25086−87. Here and hereinafter. — Note the manufacturer’s database.
1. This standard establishes General requirements for methods of analysis of lithium, produced according to GOST 8774−75.
2. General requirements for methods of analysis GOST 25086−81 with the additions indicated in the claims.2.1−2.14.
2.1. The selection and preparation of samples for analysis of lithium — GOST 8774−75.
2.2. For the preparation of solutions and the analysis use distilled or deionized water that meets the performance requirements of GOST 6709−72.
2.3. Glassware and equipment laboratory glass — GOST 25336−82.
2.3.1. Allowed to use other equipment, and other materials, utensils and reagents, subject to obtaining the metrological characteristics are not worse than specified in relevant standard methods of analysis.
2.4. Mass fraction of lithium and impurities determined in two batches.
2.5. Discrepancies between the results of parallel measurements (in %) should not exceed the permissible differences calculated at confidence probability
0,95 according to the formula
where is the relative standard deviation of precision definitions;
— the arithmetic mean of the result, %.
2.6. The discrepancy between the results of single definitions (in %) should not exceed the permissible differences calculated at confidence probability
0,95 according to the formula
where is the relative standard deviation reproducibility definitions;
— the arithmetic mean of the result, %.
2.7. The result of the analysis (), %, is calculated by the formula
where ,
— the results of the 1st and 2nd definitions
— the error of the result of the analysis under the conditions of the PP.2.5, 2.6.
2.8. The random error of test result (in %) is calculated according to the formula
2.9. The error analysis result does not exceed the limit (in%) calculated according to the formula
where — non-excluded systematic error of the result of the analysis presented in the standards.
If insignificant compared to the random error, the uncertainty of the analysis result calculated by the formula
. (6)
2.10. The numerical value of the result of the analysis should be terminated with a figure the same category as the limit of error , expressed as one significant figure.
2.11. The discrepancy between the results of two analyses and
should not exceed the permissible differences
calculated by the formula
where is the relative standard deviation of reproducibility of the tests specified in the standards;
,
— the results of the analysis, %.
2.12. The calculated error of the concentration of components in the samples for calibration or calibration solutions should be less than the error of analysis of relevant content no less than 3 times.
2.13. Control of accuracy of analysis results is carried out at least once a month, and also when replacing the reagents, equipment and materials in the manner prescribed in the standard methods of analysis (variation of the mass of sample by the method of additions).
2.13.1. Control of accuracy of analysis results by the method of additions is performed by finding the content of the analyte in the test sample after introduction of the respective additives of this component to the sample or the sample solution with the minimum value of the mass fraction of the designated component.
The amount of additives is chosen so that the analytical signal increased 1.5−2 times compared with the analytical signal of this component in the absence of additives. Analysis of sample the samples with the additive and calculation of result of analysis carried out from the same number of definitions that in the analysis of the samples. The value found Supplement, is calculated as the difference between the mass fraction of detectable component in the sample with the additive () and result analysis samples (a
) without additives.
The results of the analysis you think is right at confidence probability of 0.95, if the found value differs from the calculated Supplement, no more than the value of (
) calculated by the formula
_______________
* Numbering corresponds to the original. — Note the manufacturer’s database.
2.13.2. Control of accuracy of analysis results by the method of variation of a sample is carried out simultaneously with the analysis of production samples. To do this, perform further analysis of two batches of one of the samples («control»), the weight of which differs from the established standard on the method of analysis is about 2 times.
The results of the analysis are considered correct if the difference between two results of analysis of control samples (and
) obtained from different batches does not exceed the value
calculated by the formula
2.14. Security requirements in the analysis of lithium — GOST 8774−75.
3. Explanation of terms used in this standard are given in Appendix.
APP
Reference
TERMS USED IN THIS STANDARD, AND EXPLANATIONS
1. The result of the determination in % — value of the mass fraction of the designated component in the sample, found in a single carrying out the whole sequence of operations required by the relevant procedure regulated in a particular standard on method of analysis.
2. The results of parallel measurements and
percentage — first and second result obtained for the independent analytical test portions of the same sample under the same conditions (one analytical lab, one set of analytical equipment, reagents, and other tools of analysis, a single analyst), and almost at the same time.
3. The result of analysis in percent — for all analysis methods except for estimation of lithium — the arithmetic mean of the results of the two definitions
4. The convergence of the results of parallel definitions — as definitions that reflect the degree of closeness to each other of the results of parallel measurements for this component, executed regulated in the specific standard method of analysis in one sample in the same conditions (one analytical lab, one set of measuring instruments and reagents, one analyst) and almost at the same time.
5. The rate of convergence of the results of parallel measurements, the relative standard deviation characterizing the convergence of the results of parallel measurements.
6. The reproducibility of the definitions — as definitions that reflect the degree of closeness to each other of the results of determinations of this component, executed regulated in the specific standard method for analyzing one sample in different conditions (different analytical laboratories, different sets of measurement equipment and reagents, different players and significantly different times).
7. An indicator of the reproducibility of the results of determinations, the relative standard deviation characterizing the reproducibility of the definitions.
