GOST 13938.12-78
GOST 13938.12−78 Copper. Methods for determination of bismuth (with Amendments No. 1, 2, 3)
GOST 13938.12−78
Group B59
INTERSTATE STANDARD
COPPER
Methods for determination of bismuth
Copper. Methods for determination of bismuth
AXTU 1709
Date of introduction 1979−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
G. P. Giganov, E. M. Peneva, A. A. Blyahman, E. D. Shuvalov, A. N. Savelieva
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. REPLACE GOST 13938.12−68
4. The standard conforms to ISO 5959−84
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced | Section number, paragraph |
| GOST 200−76 |
2 |
| GOST 859−78 |
Chapeau; 5.1 |
| GOST 2062−77 |
2 |
| GOST 3118−77 |
2; 5.1 |
| GOST 3760−79 |
2; 5.1 |
| GOST 3773−72 |
2 |
| GOST 4147−74 |
2 |
| GOST 4201−79 |
2 |
| GOST 4204−77 |
2 |
| GOST 4208−72 |
2 |
| GOST 4232−74 |
2 |
| GOST 4328−77 |
2 |
| GOST 4461−77 |
2; 5.1 |
| GOST 5456−79 |
2 |
| GOST 5457−75 |
5.1 |
| GOST 5817−77 |
2 |
| GOST 8864−71 |
2 |
| GOST 9849−86 |
5.1 |
| GOST 10652−73 |
2 |
| GOST 10928−90 |
2; 5.1 |
| GOST 13938.1−78 |
1 |
| GOST 18300−87 |
2 |
| GOST 20015−88 |
2 |
6. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
7. REPRINT (November 1999) with Amendments No. 1, 2, 3, approved in may 1982, June 1985, April 1988 (IUS 8−82, 8−85, 7−88)
This standard establishes photometric (for the mass concentration of 0.00005 to 0.02%) and atomic absorption (mass fraction of from in the 0.0003 to 0.005%) methods for determination of bismuth in copper of all grades according to GOST 859*.
______________
* On the territory of the Russian Federation GOST 859−2001, here and hereafter. — Note the manufacturer’s database.
The photometric method is based on the formation of the iodide complex of bismuth in sulfuric acid solution. Bismuth is separated from interfering elements by coprecipitation with ferric hydroxide or by extraction of the bismuth diethyldithiocarbamate chloroform. Optical density of the solution godenovo complex of bismuth measured at wavelengths of 450−470 nm.
Atomic absorption method is based on dissolving the sample in nitric acid, the separation of bismuth on the iron hydroxide and subsequent measurement of the absorption of bismuth in hydrochloric acid solution at a wavelength of 223,1 nm in the flame acetylene-air.
(Changed edition, Rev. N 3).
1. GENERAL REQUIREMENTS
General requirements for methods of analysis and safety requirements when performing analyses according to GOST 13938.1.
Sec. 1. (Changed edition, Rev. N 3).
2. APPARATUS, REAGENTS AND SOLUTIONS
Spectrophotometer or photoelectrocolorimeter with all accessories.
Centrifuge.
Nitric acid according to GOST 4461.
The acid chloride.
Sulfuric acid according to GOST 4204, 5 mol/DMsolution.
Hydrochloric acid according to GOST 3118 and diluted 1:1 and 0.2 mol/DMsolution.
Bromatologia acid according to GOST 2062.
Ammonia water according to GOST 3760.
Iron trichloride 6-water according to GOST 4147, 1% solution in 0.2 mol/DMhydrochloric acid solution.
1 cmof solution contains 2 mg of iron.
Sodium hydroxide according to GOST 4328, 8% solution.
Chloroform according to GOST 20015.
Ammonium chloride according to GOST 3773, 20% solution.
Tartaric acid according to GOST 5817, 20% solution.
Hydroxylamine hydrochloric acid according to GOST 5456, 10% solution.
Potassium cyanide, 10% solution.
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid, dvuvodny (Trilon B) according to GOST 10652, 5% solution.
Sodium diethyldithiocarbamate (Na-DDTC) according to GOST 8864 solution: 2 g Na-DDTC dissolved in 100 cmof water in which was previously dissolved 1 g of acidic sodium carbonate. The solution was filtered.
Thymolphthalein, 0,4% solution in ethanol.
Sodium carbonate acidic, GOST 4201.
Wash solution: to 30 cmof a solution of di-Na-EDTA pour 1000 cm
water, 10 cm
solution of potassium cyanide and 1 cm
of a solution of thymolphthalein. Poured dropwise a solution of ammonium chloride until the disappearance of blue color.
Sodium hypophosphite according to GOST 200, 30% solution.
Ethyl alcohol 96% according to GOST 18300.
Salt of protoxide of iron and ammonium double sulfate (salt Mora) according to GOST 4208.
Potassium iodide according to GOST 4232, solution: 200 g of potassium iodide dissolved in 300 cmof water is added 30 cm
of a solution of sodium hypophosphite and top up with water to 1000 cm
.
Bismuth metal according to GOST 10928.
Standard solutions of bismuth:
Solution a: 0,100 g of bismuth dissolved in 5 cmof nitric acid. Nitrogen oxides is removed by heating. The solution is cooled and placed in a measuring flask with volume capacity of 1000 cm
, 65 cm poured
nitric acid, made up to the mark with water and mix.
1 cmof solution A contains 0.1 mg of bismuth.
Solution B: 50 cmsolution And placed in a volumetric flask with a capacity of 500 cm
, pour 5 cm
of nitric acid, made up to the mark with water and mix; store no more than 5 hours.
1 cmof a solution contains 0.01 mg of bismuth.
Universal indicator paper.
Nitric acid according to GOST 4461 and a solution of 1:1.
Ascorbic acid, a solution of 50 g/lfreshly prepared.
(Changed edition, Rev. N 1, 3).
3. ANALYSIS
3.1. A sample of copper (tab.1) is placed in a beaker with a capacity of 250 cm, is dissolved in 5−10 cm
of nitric acid and 20−40 cm
of hydrochloric acid under the watch glass.
Table 1
| Mass fraction of bi, % |
The mass of charge, g |
| 0.00005 to 0,0003 incl. |
10 |
| SV. The 0.0003 «to 0.001 « |
5,0 |
| «Of 0.001» to 0.005 « |
3,0−1,0 |
| «0,005» 0,01 « |
0,5 |
The solution was evaporated to approximately 5 cm, add 100 cm
water and 5 cm
of a solution of iron. The solution is heated to 50−60 °C and add solution of ammonia, diluted 1:1 in such quantity that the whole of the copper passed into the ammonia complex, and in excess of 10 cm
.
The contents of the beaker are heated to 70−80 °C and leave for 20−30 min the Precipitate of hydroxide is filtered on a medium density filter and washed on the filter 3−4 times with hot water.
The precipitate from the filter washed with hot water into a glass, which conducted the deposition, and added 5 cmof hydrochloric acid (1:1), the filter washed with hot water until complete removal of iron.
(Changed edition, Rev. N 1, 3).
3.1. The solution was evaporated to a volume of 2 cmand add 10 cm
of water 5 cm
of tartaric acid solution, 3 cm
of the solution Trilon B and 0.1 cm
of a solution of thymolphthalein. Added dropwise a solution of sodium hydroxide until the color changes from orange to blue. To the solution add 1 cm
of a solution of hydrochloric acid hydroxylamine and 3 cm
of a solution of potassium cyanide and after mixing — 3 cm
of a solution of ammonium chloride to a pH of 9−10. At a different pH was added to a solution of sodium hydroxide or a solution of ammonium chloride. The solution was transferred to a separatory funnel, pour 50 cm
water and 1 cm
of solution of Trilon B. Then add 10 cm
of chloroform and shaken for 2 min. the Organic phase is placed in a second separatory funnel. The aqueous phase is extracted twice: first 10 cm
, then 5 cm
of chloroform, shaking each time for 2 minutes, adding before each extraction of 1 cm
of a solution of Na-DDTC. The organic phases are combined and washed for 5 min 15 cm
wash solution, to which is added one drop of a solution of Na-DDTC.
From the washed organic phase bismuth extravert twice, each time adding 10 cmof hydrochloric acid (1:1) and shaking for 2 min. combined hydrochloric acid reextract placed in a beaker and evaporated to dryness. The residue is dissolved in 5 cm
of nitric acid and 2 cm
of perchloric acid and then evaporated to dryness.
If the residue is colored, repeat the processing of nitric and perchloric acids. Discolored residue is dissolved by heating in 2 cmof sulfuric acid solution. The solution was then cooled, placed in a volumetric flask with a capacity of 10 cm
, add water up to 6−7 cm
, and 1 cm
of a solution of sodium hypophosphate. After 10 minutes, add 1 cm
of a solution of potassium iodide, the solution is topped up to the mark with water and mix.
If the solution is opaque, then put the contents of the volumetric flask into a test tube for centrifuge and tsentrifugirujut for 5 or filtered. Optical density of the solution measured at a wavelength of 450−470 nm. Solution comparison is water.
In parallel control experiments carried out with all applied reagents and solutions, but without adding copper.
The average value of the optical density of solutions of control experiments is subtracted from the value of the optical density of the analyzed solution.
3.1 b. The solution is poured water to a volume of 50 cm. The precipitation of the hydroxide with aqueous ammonia again, as stated in claim 3.1. The resulting solution was evaporated to 3−5 cm
, were placed in a glass with a capacity of 100 cm
and evaporated almost to dryness. To the residue add 1 cm
of nitric acid, heated until the oxides of nitrogen, cool, add 3 cm
of perchloric acid and evaporated to fumes of perchloric acid. The solution is cooled, add 2 cm
bromatological acid and evaporated to moist residue.
To the residue add 2 cmof sulfuric acid solution, 1 cm
of a solution of sodium hypophosphite and 1 cm
of water and heated until dissolved. The solution is kept at a temperature of 70−80 °C for 10 min. the Solution was then cooled, placed in a volumetric flask with a capacity of 10 cm
, add 1 cm
of a solution of potassium iodide, made up to the mark with water and mix. Then do as stated in claim 3.1.
3.1 a, 3.1 b. (Added, Rev. N 1).
3.1 Determination of bismuth may be carried out: the filtrate obtained according to claim 3.1, is heated to 40−50 °C and to it was added dropwise a solution of tin dvuhkletevogo to darkening of the solution and 1 cm. Add a little filtrowanie mass, heated to boiling and leave on for 10−15 minutes at a temperature of 70−80 °C to coagulate the precipitate. The precipitate is then filtered on a dense filter in the cone which is enclosed filtrowania weight, and washed 3−4 times with hot water. Filter the precipitate discarded.
To the filtrate pour 4 cmof solution of tartaric acid, 5 cm
of a solution of potassium iodide and 1.0 to 1.5 cm
of the ascorbic acid solution, mix, place the resulting solution in a volumetric flask with a capacity of 50 cm
, is diluted to the mark with water and mix again. After 10−15 minutes, measure the optical density at a wavelength of 434−450 nm in a cuvette with a layer thickness of 30 or 50 mm. Solution of comparison is water. Mass of bismuth determined by the calibration schedule.
(Added, Rev. N 3).
3.2. To build a calibration curve in six of the seven glasses with a capacity of 250 cmis placed 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cm
of solution B. In all the cups put on 5 cm
of hydrochloric acid (1:1), 5 cm
of a solution of ferric chloride and add water to 50−60 cm
. Then add aqueous ammonia to obtain pH 7.5−8.5 and 2 cm
in excess. The solution is heated to a temperature of 70−80 °C and then act as described in section 3.1.
According to the obtained values of optical density of solutions and the corresponding content of bismuth build the calibration graph.
(Changed edition, Rev. N 1, 3).
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of bi () is calculated by the formula
where is the mass of copper, g;
— weight of bismuth, was found in the calibration schedule,
(Changed edition, Rev. N 1).
4.2. Discrepancies in the results of two parallel measurements and the two tests should not exceed the values given in table.2.
Table 2
| Mass fraction of bi, % | The absolute maximum discrepancy, %, results | |
| parallel definitions |
tests | |
| 0.00005 to 0,00010 incl. |
0,00002 |
0,00002 |
| SV. Of 0.0001 «to 0.0003 « |
0,0001 |
0,0002 |
| «To 0.0003» 0,0010 « |
0,0002 |
0,0003 |
| «0,0010» 0,0030 « |
0,0004 |
About 0.0006 |
| «0,0030» 0,0050 « |
About 0.0006 |
0,0009 |
| «0,005» 0,020 « |
0,002 |
0,005 |
(Changed edition, Rev. N 3).
5. ATOMIC ABSORPTION METHOD
5.1. Equipment, reagents, solutions
Spectrophotometer atomic absorption of any type.
Corrector of the background.
A radiation source for bismuth.
Acetylene according to GOST 5457.
Air compressor.
Nitric acid according to GOST 4461, solution 1 mol/DMand 1:1.
Hydrochloric acid according to GOST 3118 and a solution of 1:1.
Ammonia water according to GOST 3760 and a solution of 1:99.
Iron according to GOST 9849, a solution of 15 g/DMin the solution nitric acid 0,1 mol/DM
.
Copper according to the GOST 859.
Bismuth GOST 10928.
Standard solutions of bismuth sec. 2.
5.2. Analysis
5.2.1. A sample of copper with a mass of 5.0 g is placed in a beaker with a capacity of 400 cmand dissolved in 20−25 cm
of a solution of nitric acid, diluted 1:1. Heated to remove oxides of nitrogen. Then pour 250 cm
water, 5 cm
of a solution of iron and heated to a temperature of 60−70 °C. ammonia is Added in such quantity that the whole of the copper passed into the ammonia complex and 5 cm
. Maintained at a temperature of 70 °C to coagulate the precipitate. After that filter the solution through a filter of medium density and the precipitate was washed 2−4 times with a hot solution of ammonia. The filter cake is dissolved in 10 cm
of hot hydrochloric acid, washed 2−3 times with hot water. The solution was then cooled, placed in a volumetric flask with a capacity of 25 cm
, is diluted to the mark with water and mix.
If necessary, the filtrate is not diluted to a volume of 25 cm, and evaporated to 6−8 cm
and analyzed.
Measure the optical density of the solution in the flame acetylene-air at a wavelength of 223,1 nm simultaneously with the solution of the control experience and solutions to build the calibration curve.
Allowed the definition in the sample solution of antimony (from 0.0005 to 0.02%), tin (0.01 to 0.06%) and lead (from 0.0005 to 0.005%).
5.2.2. To build a calibration curve of seven glasses with a capacity of 400 cmis placed in 5.0 g of copper and act as described in claim 3.2. Then, in six of the seven glasses are placed 1,5; 5,0; 10,0; 15,0; 20,0 and 25 cm
standard solution B, and continue the analysis as described in section 3.2.
According to the obtained results build a calibration curve.
5.3. Processing of the results
5.3.1. Mass fraction of bismuth () in percent is calculated by the formula
where — weight of bismuth, was found in the calibration graphics mg;
— capacity volumetric flasks, cm
;
— weight of copper,
5.3.2. The discrepancy between the results of two parallel measurements and the two tests should not exceed the values given in table.2.
5.3.3. The differences in the assessment of mass fraction of bismuth used the photometric method.
Sec. 5. (Added, Rev. N 3).
