GOST 20997.0-81
BL 6−99
GOST 20997.0−81
INTERSTATE STANDARD
THALLIUM
GENERAL REQUIREMENTS FOR METHODS OF SPECTRAL ANALYSIS
Edition official
IPK PUBLISHING house of STANDARDS, Moscow
INTERSTATE STANDARD
THALLIUM
General requirements for methods of spectral analysis
Thallium.
General requirements for methods of spectral analysis AXTU 1709
GOST
20997.0−81* *
Instead
GOST 20997.0−75
The decision of the State Committee USSR on standards on 25 may 1981 No. 2589 the introduction of set
with 01.07.82
Resolution of the state standard from
1. This standard establishes General requirements for methods of spectral analysis of thallium in all grades according to GOST 18337−95.
General requirements for methods of analysis GOST and GOST 25086−87 22306−77.
(Changed edition, Rev. No. 1, 2).
2. The selection and preparation of samples is carried out according to GOST 18337−95.
3. For the preparation of aqueous solutions and analysis used distilled water according to GOST 6709−72, purified on ion-exchange column or distilled in a quartz apparatus.
4. 5. (Deleted, Rev. No. 2).
6. Evaporation of samples was carried out at a temperature not higher than 90 °C.
7. For the manifestation of photographic plates using the metol-hydrochinone developer consisting of two solutions which, before manifestation, are mixed in the ratio 1:2.
Solution 1:
distilled water GOST 6709−72 to… 1 dm3
potassium carbonate according to GOST 4221−76… 60 G.
Solution 2:
distilled water GOST 6709−72 to… 2 dm3
metol according to GOST 25664−83… 6 g
hydroquinone according to GOST 19627−74… 15 g
sodium sanitarily according to GOST 195−77… 90 g
potassium bromide according to GOST 4160−74… 6 G.
Allowed to apply contrast-the developer of another composition.
Fixer is acidic.
8. The final result of the analysis be the arithmetic mean of results of four parallel samples (each simultaneous determination obtained from the two spectrograms) with chemical-spectral method and two parallel definitions (each definition get the parallel of the three spectrograms) when spectrographic method. The maximum discrepancies of the results of parallel measurements id) and the results of the two analyses (D) calculated
Official edition Reprinting is prohibited
* Edition (January 2001) with Amendments No. 1, 2 approved in November 1986 April 1992
(ICS 2−87, 7−92)
© Standards publishing house, 1981 © IPK Publishing house of standards, 2001
GOST 20997.0−81 C. 2
confidence probability P = 0,95, shall not exceed the established standards of permissible values of the differences (d).
Numeric values of analysis results are rounded in expressing a number with the last digit of the same rank as that of a numeric value permissible discrepancies in the results of parallel measurements.
9. Control of correctness of the analysis carried out during the replacement of the party samples of the comparison, the repair spectrographic installations, after long interruptions and other changes that affect the result of the analysis.
8, 9. (Changed edition, Rev. No. 2).
10. Safety requirements
10.1. Thallium in the form of metal and its compounds is highly toxic product and apply according to GOST 12.1.005−88 for substances of 1st hazard class. Hazard — food poisoning. The maximum permissible concentration of thallium in air of a working zone of production areas according to the GOST 12.1.005−88 — 0,01 mg/m3
10.2. General safety requirements when working with thallium and its compounds — according to GOST 18337−95.
10.3. The analysis of thallium are used in small amounts of toxic substances shown in the table.
| The name of the substance | Hazard class and hazard according to GOST 12.1.007−76 | Maximum permissible concentration in mg/m3 according to GOST 12.1.005−88 |
| Mercury metal | 1 — poisoning | 0,01/0,005 |
| Caustic soda | 2 — burn | 0,5 |
| PP'-dichloroethylenes live | 3 — poisoning | 2,0 |
| Bromine | 2 — poisoning | 0,5 |
| Benzene | 2 — poisoning | 5,0 |
Control of content of harmful substances in the preparation of calibration samples (thallium, mercury, sodium hydroxide) and to perform the analysis of thallium in workplace air should be performed periodically to substances of 1st hazard class (thallium, mercury) once a day and for substances 2, 3rd hazard classes once a month on a schedule approved by management.
Determination of thallium in air of working zone is carried out according to Annex 1 GOST 18337−95.
The determination of mercury vapor, sodium hydroxide, PP'-dichlorodifluoro ether, bromine, benzene in the air of working zone is carried out according to methodical instructions by definition of harmful substances in the air, approved by Chief sanitary doctor of the USSR.
10.4. When performing analysis of thallium it is necessary to observe the basic rules of safe work in chemical laboratories approved by Hoshikatta of the USSR.
(Changed edition, Rev. No. 1).
10.5. Electrical appliances used in the tests shall conform to the regulations for electrical installations, approved by Gosenergonadzor. In the use and operation of electrical appliances and electrical installations in the process of spectral analysis required to comply with the rules of technical operation of electrical installations and safety regulations for operation of consumers, approved by Gosenergonadzor.
10.6. Working in the chemical and spectral laboratories should be provided with overalls and means of individual protection in accordance with typical industry norms of free issue of workwear, footwear, protective equipment, approved by the USSR State Committee for labour and social Affairs.
10.7. To work in chemical and spectral lab allowed a person trained in the requirements of safe work in laboratories according to GOST 12.0.004−90.
Editor of M. I. Maksimova Technical editor L. A. Guseva Corrector V. I. Barents DTP S. V. Ryabova
Ed. No. 02354 from
Circulation 124 specimens From 278. Zach. 166.
IPK Publishing house of standards, 107076, Moscow, kolodezny per., 14.
Typed in the Publisher on PC
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