GOST 3240.10-76
GOST 3240.10−76 magnesium Alloys. Method for the determination of lithium (with Change No. 1)
GOST 3240.10−76
Group B59
INTERSTATE STANDARD
MAGNESIUM ALLOYS
Method for the determination of lithium
Magnesium alloys.
Method for determination of lithium
ISS 77.120.20
AXTU 1709
Date of introduction 1978−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of aviation industry of the USSR
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. INTRODUCED FOR THE FIRST TIME
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Section number, paragraph |
| GOST 8.315−97 |
Sec. 5 |
| GOST 804−93 |
Sec. 2 |
| GOST 3118−77 |
Sec. 2 |
| GOST 3240.0−76 |
1.1 |
| GOST 5457−75 |
Sec. 2 |
| GOST 25086−87 |
Sec. 5 |
5. Limitation of actions taken by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)
6. EDITION with Change No. 1, approved in June 1987 (IUS 11−87)
This standard sets flame photometric method for the determination of lithium (when lithium mass fraction of from 10 to 25%).
The method is based on measuring the intensity of the resonance line of lithium at 
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 3240.0.
2. APPARATUS, REAGENTS AND SOLUTIONS
The fiery photometer or spectrophotometer.
Acetylene in cylinders GOST 5457.
Hydrochloric acid according to GOST 3118 and diluted 1:1.
Primary magnesium ingots according to GOST 804 in the form of chips.
The solution of magnesium and 20 g/DM.
20 g of magnesium are dissolved in 300 cmof hydrochloric acid diluted 1:1, transferred into a volumetric flask with a capacity of 1 DM
, dilute to the mark with water and mix.
1 cmof the solution contains 0.02 g of magnesium.
Lithium carbonate, H. h
Standard solution of lithium: 5,324 g previously dried at 100−105 °C to constant weight of lithium carbonate is placed in a tall glass, moisten with water and gradually pour hydrochloric acid diluted 1:1 before the enlightenment of the solution. After dissolution the solution was transferred to volumetric flask with a capacity of 1 DM, dilute to the mark with water and mix.
1 cmof the solution contains 1 mg of lithium.
Sec. 2. (Changed edition, Rev. N 1).
3. ANALYSIS
3.1. A sample of alloy weighing 0.2 g (sample before analysis stored in supervisionand buksh) was dissolved in 10 cmof hydrochloric acid diluted 1:1 in a beaker or conical flask with a capacity of 100 cm
. The solution was transferred to a volumetric flask with a capacity of 100 cm
, cooled and diluted to the mark with distilled water and mix. 10 cm,
transferred to a volumetric flask with a capacity of 100 cm
, add 20 cm
of hydrochloric acid, dilute to the mark with water and mix. In parallel spend control experience. Solutions photometric at a wavelength of 670,8 nm. Inject the solution into the atomizer device and record the readings.
In order to avoid errors in unstable operation of the device every four samples of the control operation of the device photoretrieval calibration solution close to the lithium content of the samples, with the subsequent adjustment of the angle of slope of calibration curve when calculating the results of the analysis of the previous four solutions, which fotometricheskie repeat.
3.2. Construction of calibration curve
In seven volumetric flasks with a capacity of 100 cm inject 1 cmof solution of magnesium, is added from burette 0; 1,0; 2,0; 3,0; 4,0; 5,0 and 6.0 cm
of a standard solution of lithium, which corresponds to 0; 1,0; 2,0; 3,0; 4,0; 5,0 and 6.0 mg lithium and add 20 cm
of hydrochloric acid. The solutions were diluted to the mark with water, mix and photometric as specified in claim 3.1. According to the measurement results build a calibration curve.
(Changed edition, Rev. N 1).
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of lithium (a) percentage calculated by the formula
where is the mass of lithium was found in the calibration schedule g;
— volume of initial solution, cm
;
— volume aliquote part, cm
;
— the weight of the portion of the sample,
(Changed edition, Rev. N 1).
4.2. Allowable absolute differences of the results of the parallel definitions should not exceed the values given in the table.
| Mass fraction of lithium, % |
The absolute allowable difference, % |
| From 10 to 15 |
0,4 |
| SV. 15 «25 |
0,6 |
5. CONTROL OF MEASUREMENT ACCURACY
To control the accuracy of measuring the mass fraction of lithium from 10 to 25% are using industry standard samples and standard samples of the enterprise of magnesium alloys, issued in accordance with GOST 8.315. Accuracy control measurement is carried out in accordance with GOST 25086.
Control the accuracy of measuring the mass fraction of lithium may be performed by a method of additives.
(Added, Rev. N 1).
