GOST 15483.2-78
GOST 15483.2−78 Tin. Methods for determination of bismuth (with Amendments No. 1, 2, 3)
GOST 15483.2−78
Group B59
INTERSTATE STANDARD
TIN
Methods for determination of bismuth
Tin. Methods for determination of bismuth
AXTU 1709
Date of introduction 1980−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
B. C. Baev, T. P. Almanova, G. M. Vlasov, C. B. Meshkova, L. V. Mishchenko, L. D. Savilov, R. D. Kresnicka
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. The standard fully complies ST SEV 4807−84
4. REPLACE GOST 15483.2−70
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
The designation of the reference document referenced |
Item number |
GOST 860−75 |
3.2 |
GOST 2062−77 |
2.2 |
GOST 3118−77 |
2.2 |
GOST 4109−79 |
2.2 |
GOST 4461−77 |
2.2; 3.2 |
GOST 6344−73 |
2.2 |
GOST 10484−78 |
3.2 |
GOST 10928−90 |
2.2; 3.2 |
GOST 15483.0−78 |
1.1 |
6. Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)
7. REVISED (April 1999) with Amendments No. 1, 2, 3, approved in August 1984, October 1985, June 1989 (IUS 12−84, 1−86, 10−89)
This standard specifies the photometric (with a mass fraction of bismuth from 0.002 to 0.1%) and atomic absorption (at a mass fraction of bismuth from 0.01 to 0.1%) methods for determination of bismuth in tin all brands except tin of high purity.
The standard fully complies ST SEV 4807.
(Changed edition, Rev. N 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis and security requirements — according to GOST 15483.0.
(Changed edition, Rev. N 1).
2. PHOTOMETRIC METHOD
2.1. The essence of the method
The method is based on dissolving the sample in a mixture of hydrochloric and bromatological acid and bromine, removing the tin in the form of bromide in the presence of perchloric acid and measurement of optical density of the complex compound of bismuth with thiourea at a wavelength of 440 nm.
(Changed edition, Rev. N 2).
2.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Hydrochloric acid according to GOST 3118.
Bromatologia acid according to GOST 2062.
Bromine according to GOST 4109.
The mixture for dissolution, cooked: 45 cmof hydrochloric acid, 45 cmbromatological acid and 10 cmof bromine.
Perchloric acid, a solution with a mass fraction of 70%.
Nitric acid according to GOST 4461, diluted 1:1.
Thiourea according to GOST 6344, solution with a mass fraction of 10%.
Bismuth metal according to GOST 10928.
A standard solution of bismuth: 0,1000 g of the metal bismuth is dissolved in 30 cmof nitric acid, diluted 1:1, and heated to remove oxides of nitrogen, cooled, transferred into a measuring flask with volume capacity of 1000 cmcontaining 100 cmof nitric acid solution, adjusted to the mark with water and mix.
1 cmof the solution contains 1·10g of bismuth.
(Changed edition, Rev. N 1, 2, 3
).
2.3. Analysis
2.3.1. Depending on the content of bismuth in the sample tin weight in accordance with table.1 is placed in a beaker with a capacity of 250 cm, 10 cm, pour themixture to dissolve, cover with a watch glass and leave you without heating to dissolve the sample. Then the hour glass is washed with 2−3 cmof hydrochloric acid, pour 5 cmof perchloric acid and evaporated until the appearance of white fumes of perchloric acid. The solution was cooled, poured 5cmof the mixture for dissolution, and again evaporated until the appearance of white vapors. If the solution is cloudy, then this operation is repeated until the enlightenment of the solution, indicating the completeness of Stripping of tin and antimony.
Table 1
Mass fraction of bi, % |
The mass of charge, g |
0.01 |
2 |
SV. The 0.01 «to 0.05 |
1 |
«0,05» 0,10 |
0,5 |
Rate of the cooled solution was transferred to volumetric flask with a capacity of 50 cm, is poured into precisely measured 20 cmof a solution of thiourea, adjusted to the mark with water and mix.
Measure the optical density of the solution at a wavelength of 440 nm. Solution comparison is the solution of the reference experiment.
The mass of bismuth in the solution found by the calibration schedule.
(Changed edition, Rev. N 1, 2).
2.3.2. To build a calibration curve in seven of the eight glasses with a capacity of 50 cmmeasure 0,4; 1,0; 2,0; 3,0; 4,0; 5,0 and 6.0 cmto the standard solution of bismuth, which corresponds to 0,04; 0,1; 0,2; 0,3; 0,4; 0,5 and 0.6 mg of bismuth. All the glasses are poured at 5 cmof perchloric acid and heated until the appearance of fumes of perchloric acid. The chilled solutions are transferred to volumetric flasks with a capacity of 50 cm. Pour 20 cmof a solution of thiourea, adjusted to the mark with water and mix. The optical density measured as described in section
(Changed edition, Rev. N 2).
2.4. Processing of the results
2.4.1. Mass fraction of bismuth () in percent is calculated by the formula
,
where — weight of bismuth, was found in the calibration schedule g;
— weight of tin,
2.4.2. Allowable absolute discrepancies in the results of parallel measurements at a confidence probability of 0.95 should not exceed the values given in table.2.
Table 2
Mass fraction of bi, % |
The absolute allowable difference, % |
From 0.002 to 0.005 |
0,001 |
SV. 0,005 «0,01 |
0,002 |
«0,01» 0,02 |
0,003 |
«0,02» 0,05 |
0,005 |
«To 0.05» to 0.08 |
0,008 |
«0,08» 0,1 |
0,010 |
(Changed edition, Rev. N 2).
3. ATOMIC ABSORPTION METHOD
3.1. The essence of the method
The method is based on dissolving the sample in a mixture of hydrofluoric and nitric acids with water and measuring the nuclear absorption of bismuth in the flame acetylene-air at a wavelength of 223,1 nm.
3.2. Apparatus, reagents and solutions
Spectrometer of atomic absorption.
The glasses are made of PTFE with a capacity of 50 cm.
Nitric acid according to GOST 4461 and diluted 1:1.
Hydrofluoric acid according to GOST 10484.
Mix to dissolve: hydrofluoric and nitric acid is mixed with water in the ratio 2:3:5 respectively. The mixture was stored in a container made of polyethylene.
Tin of high purity according to GOST 860.
Bismuth GOST 10928.
Solution bismuth standard; prepared as described in step 2.2.
3.1, 3.2. (Changed edition, Rev. N 2).
3.3. Analysis
3.3.1. A portion of tin weighing 1 g is placed in a beaker made of PTFE with a capacity of 50 cmand poured in small portions to 10 cmof the mixture for dissolution, making sure that the reaction did not proceed rapidly. After dissolving the contents of the beaker heated for 1−2 minutes, without boiling, cooled, transferred to a volumetric flask with a capacity of 50 cm, adjusted to the mark with water and mix.
Measure the atomic absorption of bismuth in the flame acetylene-air at a wavelength of 223,1 nm in parallel with solutions for constructing the calibration curve and the reference experiment. The concentration of bismuth in the solution found by the calibration schedule.
3.3.2. To build a calibration curve of seven glasses of PTFE was placed 1.0 g of tin of high purity, dissolved in 10 cmof the mixture for dissolution, making sure that the reaction did not proceed rapidly. After dissolving the contents of the beaker heated for 1−2 minutes, without boiling, and cooled.
The solutions were transferred to volumetric flasks with a capacity of 50 cmand six of them measure 1,0; 2,0; 4,0; 6,0; 8,0 and 10,0 cmstandard solution of bismuth, which corresponds to 0,1; 0,2; 0,4; 0,6; 0,8 and 1,0 mg of bismuth. Solutions was adjusted to the mark with water and mix. Measure the atomic absorption of bismuth, as stated in claim
According to the obtained values of atomic absorption and corresponding concentrations of bismuth build the calibration graph.
3.3.1,
3.4. Processing of the results
3.4.1. Mass fraction of bismuth () in percent is calculated by the formula
,
where is the concentration of bismuth was found in the calibration schedule, g/cm;
— the concentration of bismuth in solution in the reference experiment, was found in the calibration schedule, g/cm;
— volume fotometricheskogo solution, cm;
— weight of tin,
(Changed edition, Rev. N 1, 2)
.
3.4.2. Allowable absolute discrepancies in the results of parallel measurements at a confidence probability of 0.95 should not exceed the values given in table.2.
(Changed edition, Rev. N 2).