GOST 6689.1-92
GOST 6689.1−92 Nickel, alloys Nickel and copper-Nickel. Methods for determination of copper
GOST 6689.1−92
Group B59
STATE STANDARD OF THE USSR
NICKEL, ALLOYS NICKEL AND COPPER-NICKEL
Methods for determination of copper
Nickel, nickel and copper-nickel alloys. Methods for the determination of copper
AXTU 1709
Date of introduction 1993−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED BY THE MINISTRY OF METALLURGY OF THE USSR
DEVELOPERS
V. N. Fedorov, B. P. Krasnov, Y. M. Leybov, A. N. Bulanova, V. M. Abalakina, L. V. Morea, O. K., Kleymenova, E. A. Vorobyova
2. APPROVED AND promulgated by the Decree of Committee of standardization and Metrology of the USSR from
3. REPLACE GOST 6689.1−80
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
This standard specifies electrogravimetry method for the determination of copper (at a mass fraction of copper in excess of 25%), extraction-photometric, photometric, polarographic and atomic absorption methods for the determination of copper (at a mass fraction of copper from 0.005 to 0.6%) in Nickel and copper-Nickel alloys according to GOST 492* and GOST 19241.
________________
* On the territory of the Russian Federation GOST 492−2006. — Note the manufacturer’s database.
1. GENERAL REQUIREMENTS
General requirements for methods of analysis GOST 25086 with the Supplement.
For the results analysis be the arithmetic mean of results of three (two) of parallel definitions.
2. ELECTROGRAVIMETRY METHOD FOR THE DETERMINATION OF COPPER
2.1. The essence of the method
The method is based on acid dissolution of the sample, separation of copper by electrolysis on a platinum cathode at a current of 1.5 to 2.5 and the determination of residual copper in the electrolyte by atomic absorption method at the wavelength of 324,7 nm in the flame acetylene-air or photometric method with cuprizone at a wavelength of 600 nm or pyramid-Epsilon at 550 nm.
2.2. Apparatus, reagents and solutions
Electrolysis installation DC.
Platinum electrodes according to GOST 6563.
Atomic absorption spectrometer with a source of radiation for copper.
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461, diluted 1:1.
Hydrochloric acid according to GOST 4204, diluted 1:1, 1:4, 1:99 and 1 mol/DM.
Hydrofluoric acid according to GOST 10484.
Ascorbic acid, a solution of 10 g/DM.
Citric acid according to GOST 3652.
Ammonia water according to GOST 3760 and diluted 1:4.
Hydrazine sulfate according to GOST 5841, a solution of 10 g/DM.
The technical rectified ethyl alcohol according to GOST 18300.
Thiourea according to GOST 6344, solution 100 g/DM.
Urea according to GOST 6691, a solution of 10 g/DM.
Ammonium citrate solution: 150 g of citric acid dissolved in 400 cmof water, add with stirring 100 cm
of concentrated ammonia solution, cool, add 100 cm
of ammonia, cooled and topped to the mark with water to 1000 cm
.
Bis-cyclohexanone-oxalyl-dihydrazone (cuprizone), solution: 2.5 g cuprizone dissolved with stirring in 900 cmof water at a temperature of 60−70 °C. After cooling, the solution was filtered into a dark glass jar, add water to volume of 1000 cm
. The solution to fit 10 days.
Pyramid-Epsilon, a solution of 1 g/DM.
Copper according to GOST 859* with a mass fraction of copper not less than 99.9%.
________________
* On the territory of the Russian Federation GOST 859−2001, here and hereafter. — Note the manufacturer’s database.
Standard solutions of copper
Solution a: 0.5 g of copper is dissolved in 10 cmof nitric acid (1:1), and remove the oxides of nitrogen by boiling, transferred to a volumetric flask with a capacity of 500 cm
, made up to the mark with water and mix.
1 cmof the solution contains 0.001 g of copper.
Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix.
1 cmof a solution contains 0.0001 g of copper.
Solution: 10 cmof solution B is placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix.
1 cmof the solution contains 0,00001 g of copper.
Nickel GOST 849*.
________________
* On the territory of the Russian Federation GOST 849−2008, here and hereafter. — Note the manufacturer’s database.
A standard solution of Nickel: 0.5 g of Nickel were placed in a glass with a capacity of 250 cm, add 15 cm
of nitric acid (1:1), cover with a watch glass or plastic plate and dissolved by heating. After dissolution and cooling of the glass or plate and the side of the Cup and rinse with water, add 5 cm
of sulphuric acid (1:1) and the solution is evaporated prior to the allocation of white smoke of sulfuric acid. The residue is cooled, rinse the walls of the glass with water and re-evaporated prior to the allocation of white smoke of sulfuric acid. After cooling, to the residue add 20−30 cm
of water and heated to dissolve the salts. After cooling, the solution was transferred to volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix.
1 cmof solution with
holds 0.01 g of Nickel.
2.3. Analysis
2.3.1. For alloys containing not more than 0.05% lead and 0.1% silicon
A sample weighing 1 g is placed in a beaker with a capacity of 300 cm, add 15 cm
of nitric acid, cover with watch glass, glass or plastic plate and dissolved by heating. After dissolution of the alloy or glass plate, the side of the Cup then rinsed with water and the solution was boiled to remove oxides of nitrogen. The solution was then diluted with water to 150 cm
and add 7cm
sulfuric acid (1:4).
Into the solution is dipped a platinum anode and a pre-weighed platinum cathode and conducting electrolysis at a current of 1.5 to 2.5 And stirring the solution.
The glass electrolyte must be closed the two halves of a glass or plastic plate with holes for the introduction into the solution of the electrodes and stirrer.
For the mass concentration in the alloy in excess of 1% of iron and manganese during electrolysis it is necessary to add small amounts (1−1. 5 cm) sulfate solution of hydrazine or urea.
After the bleaching solution the side of the Cup, glass or plate and protruding parts of the electrodes are then rinsed with water and continue the electrolysis for another 10−15 min at a current of 0,5 A.
If svezhemorozhenoj portion of the cathode is not allocated the sediment of copper and the electrolysis is complete. Otherwise, the electrolysis is carried out for 10−15 min and re-control of the completeness of separation of copper.
At the end of the electrolysis without turning off the current, the electrodes are then rinsed with water, collecting the washings in the beaker with the electrolyte. Current is turned off, the cathode and the precipitate was immersed in a beaker with 200 cmof ethyl alcohol and dried at 105 °C to constant weight. One serving of alcohol may be used for washing no more than 20 electrodes.
The electrolyte can be used to determine other elements such as iron by the photometric method and Nickel by gravimetric method.
2.3.2. For Sventevith Nickel silver
A sample weighing 1 g is placed in a beaker with a capacity of 300 cm, add 15 cm
of nitric acid, cover the beaker watch glass, glass or plastic plate and dissolved by heating. After dissolution of the alloy watch glass or plate and the side of the Cup then rinsed with water and the solution was boiled to remove oxides of nitrogen. The solution was then diluted with water to 150 cm
, immersed into a pre-weighed platinum electrodes and conduct electrolysis at a current of 1.5 to 2.5 and stirring the solution.
After 30 min the solution was added 7 cmof sulphuric acid (1:4) and further electrolysis is carried out as specified in clause
The anode from the separated precipitate of lead dioxide, rinsed with water and dried at a temperature of 160−170 °C to constant weight and calculated mass fraction of lead GOST 6689.20.
2.3.3. For alloys containing more than 0.1% silicon
A sample of alloy weighing 1 g is placed in a platinum Cup, add 15 cmof nitric acid, 1−2 cm
hydrofluoric acid, cover made of platinum or PTFE and dissolved by heating. After dissolution of the alloy walls of the Cup and rinse the cover with water, add 10 cm
sulphuric acid (1:1) and evaporated to release white smoke of sulfuric acid. The residue is cooled and dissolved in water when heated. The solution was transferred to a beaker with a capacity of 300 cm
, dilute with water to 150 cm
, add 5 cm
boiled nitric acid and the electrolysis is carried out as specified in clause
2.4. Determination of residual copper in the electrolyte
The electrolyte, after separation of copper is evaporated to a volume of 80 cm, transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with water, mixed and used in the determination of copper in PP.2.4.1. and
2.4.1. Determination of copper by atomic absorption spectrometry
2.4.1.1. Measure the atomic absorption of copper in the flame acetylene — air at a wavelength of 324,7 nm parallel to the calibration solutions.
2.4.1.2. Construction of calibration curve
In six of the seven volumetric flasks with a capacity of 100 cmis placed 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cm
standard solution B copper. To all flasks add 5 cm
of nitric acid (1:1) and sulfuric (1:1) acid is added to the mark with water and measure the atomic absorption of copper, as indicated in claim
2.4.2. Definition of copper by the photometric method with cuprizone
2.4.2.1. Aliquot part of the solution is 20 cmis placed in a volumetric flask with a capacity of 100 cm
, add 10 cm
of a solution of ammonium citrate and ammonia solution (1:4) to slightly alkaline reaction, then add 2 cm
of ammonia (1:4), 10 cm
solution cuprizone immediately topped up to the mark with water and mix. the pH of the obtained solution should be of 8.5−9.0. After 5 min, but not later than 30 min, measure the optical density of the solution on a photoelectrocolorimeter with an orange filter in a cuvette with a thickness of the light absorbing layer 3 cm, or on the spectrophotometer at 600 nm in a cuvette with the thickness of the light absorbing layer 1 see Solution comparison is the solution of the reference experiment.
2.4.2.2. Construction of calibration curve
In six of the seven volumetric flasks with a capacity of 100 cmis placed 0,5; 0,75; 1,0; 1,5; 2,0 and 2,5 cm
standard solution B copper. To all flasks add 5 cm
of nitric acid (1:1), 10 cm
of a solution of citrate of ammonium and further analyze as described in section
Solution comparison is the solution not containing copper. According to the obtained results build a calibration curve.
2.4.3. Definition of copper by the photometric method with pyramid-Epsilon
The electrolyte, after separation of copper is evaporated to a volume of 40−50 cm, after cooling, add 2 cm
of sulphuric acid (1:1) and the solution is evaporated prior to the allocation of white smoke of sulfuric acid. The residue is cooled, rinse the walls of the glass with water and re-evaporated prior to the allocation of white smoke of sulfuric acid. After cooling, to the residue add 20−30 cm
of water and heated to dissolve the salts. After cooling, the solution was transferred to volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix.
2.4.3.1. Aliquot part of the solution 1 cmis placed in a volumetric flask with a capacity of 50 cm
, up to 4 cm
of sulphuric acid (1 mol/DM
), 2 cm
of ascorbic acid solution, 2 cm
of mortar pyramid-Epsilon, made up to the mark with water and mix.
Measure the optical density of the solution on the spectrophotometer at 550 nm or photoelectrocolorimeter with a yellow filter in a cuvette with a thickness of the light absorbing layer 2 see
Solution comparison is the solution of the same sample just before adding pyramid-Epsilon is administered 2 cmof a solution of thiourea
.
2.4.3.2. Construction of calibration curve
In six of the seven volumetric flasks with a capacity of 50 cmis placed 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cm
of a standard solution of copper. To all flasks add 3 cm
of a standard solution of Nickel, 2 cm
of sulphuric acid (1 mol/DM
), 2 cm
of ascorbic acid solution and further analysis is carried out as specified in clause
Solution comparison is the solution not containing copper.
According to the obtained results build a calibration curve.
2.5. Processing of the results
2.5.1. Mass fraction of copper in the cent in the case of determination of residual copper in the electrolyte by atomic absorption spectrometry described by the formula
,
where is the mass of the cathode with segregated copper, g;
— the mass of cathode, g;
— the mass of sample, g;
— the concentration of copper was found in the calibration schedule, g/cm
.
— the volume of the electrolyte solution, cm
.
2.5.2. Mass fraction of copper in the cent in the case of determination of residual copper in the electrolyte by the photometric method is calculated by the formula
,
where is the mass of the cathode with segregated copper, g;
— the mass of cathode, g;
— weight alloy, g;
— the mass of copper was found in the calibration schedule g;
— the volume of the electrolyte, cm
;
— volume aliquote part of the solution, cm
.
2.5.3. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.1.
Table 1
2.5.4. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) of copper-Nickel alloys, approved under GOST 8.315* in accordance with GOST 25086.
________________
* On the territory of the Russian Federation GOST 8.315−97, here and hereafter. — Note the manufacturer’s database.
3. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF COPPER
3.1. The essence of the method
The method is based on the substitution of ions copper ions of lead in his diethyldithiocarbaminate complex, dissolved in chloroform, and measuring the optical density of the extract of diethyldithiocarbaminate copper.
3.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461, diluted 3:2; 1:2; 1:1 and 1:100.
Sulfuric acid according to GOST 4204, diluted 1:3.
Hydrochloric acid according to GOST 3118, diluted 1:1.
Hydrofluoric acid according to GOST 10484.
Tartaric acid according to GOST 5817, a solution of 400 g/DM.
Ammonia water according to GOST 3760, diluted 1:1.
Sodium hydroxide according to GOST 4328, solution 100 g/DM.
Sodium sulfate according to GOST 4166.
Potassium-sodium vinocity according to GOST 5845, a solution of 100 g/cm.
Lead acetate according to GOST 1027.
Methyl orange, solution 1 g/cm.
Chloroform according to GOST 20015.
Diethyldithiocarbamate sodium GOST 8864.
Lead diethyldithiocarbamate solution in chloroform: 0.1 g of lead diethyldithiocarbamate dissolved in 100−200 cmof chloroform and diluted with chloroform up to 1 DM
or 0.1 g of lead acetate dissolved in 20 cm
of water, add 5 cm
of the solution Vinokurova potassium-sodium and injected dropwise sodium hydroxide solution until the disappearance of turbidity. Dissolve 0.125 g of sodium diethyldithiocarbamate in 40 cm
of water and add to the first solution. The resulting solution together with the precipitate is placed in a separating funnel with a capacity of 500 cm
, add 200−250 cm
of chloroform and extracted 2 minutes and the Extraction repeated. The chloroform extracts are combined, filtered through a dry filter into a dry flask made of dark glass with a glass stopper and diluted with chloroform up to 1 DM
.
Copper of mark M0 GOST 859.
Standard solutions of copper
Solution a: 0.1 g of copper is dissolved in 20 cmof nitric acid (1:1), boil to remove oxides of nitrogen, cooled, transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water.
1 cmof the solution contains 0.0001 g of copper.
Solution B: 25 cmsolution And placed in a volumetric flask with a capacity of 250 cm
, made up to the mark with water.
1 cmof solution B contains 0,0
0001 g of copper.
3.3. Analysis
3.3.1. For alloys containing less than 0.1% of silicon and not containing chromium and tungsten
A portion of the alloy 0.5 g were placed in a glass with a capacity of 250 cm, add 15 cm
of nitric acid (3:2), cover with watch glass, glass or plastic plate and dissolved by heating. Glass or plate and the side of the Cup then rinsed with water and the solution was boiled to remove oxides of nitrogen. When the mass fraction of copper is less than 0.02% for the analysis using the entire solution, and the copper content in excess of 0.02% solution transferred to a volumetric flask with a capacity of 100 cm
and then filled to the mark with water.
Aliquot part or all of the solution (table.2) is placed in a separating funnel with a capacity of 150 cm, dilute with water to 25 cm
, add 5 cm
of a solution of tartaric acid, neutralized with ammonia solution till alkaline medium for methyl orange, add 2−3 drops of sulfuric acid (1:3) and dilute the solution to 50 cm
water.
Table 2
Add 10 cmof a solution of lead diethyldithiocarbamate in chloroform and extracted 3 minutes After separation of the layers, the chloroform layer is painted in yellow color, is transferred into a volumetric flask with a capacity of 25 cm
.
The copper from the water layer extracted two more times for 2 min each time priliva 5 cmof a solution of lead diethyldithiocarbamate in chloroform, and combine the organic layers painted in a volumetric flask. The extracts in the volumetric flask, topped to the mark with chloroform and dehydrated by adding 0.2 g of anhydrous sodium sulfate or by filtering through dry filter paper.
Optical density of the solution is measured on a photoelectrocolorimeter with a blue filter in a cuvette with a thickness of the light absorbing layer 2 cm or with spectrophotometer at 436 nm in a cuvette with the thickness of the light absorbing layer 1 cm as a solution of comparison, using chloroform. Through all stages of the analysis carried out control experience in the copper content in the applied chemicals and make the appropriate amendment.
3.3.2. For alloys containing tungsten
A portion of the alloy 0.5 g were placed in a glass with a capacity of 250 cm, add 15 cm
of nitric acid (3:2), cover with watch glass, glass or plastic plate and dissolved by heating. Glass or plate and the side of the Cup then rinsed with water and the solution is evaporated to a syrupy condition. To the residue add 25−30 cm
of hot water, heated to 60−70 °C and the precipitate tungsten acid is filtered off on a tight filter, carefully washed the beaker and the precipitate with nitric acid (1:100). The precipitate is discarded. When the mass fraction of copper is less than 0.02%, the filtrate is evaporated to a volume of 20 cm
, while the mass fraction of copper in excess of 0.02% is transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with water and further analysis are as indicated in claim
3.3.3. For alloys containing more than 0.1% of silicon and chromium
A portion of the alloy 0.5 g was placed in a platinum Cup, add 15 cmof nitric acid (3:2), 3 cm
hydrofluoric acid and dissolved by heating. After cooling, add 5 cm
of concentrated sulfuric acid and the solution is evaporated prior to the allocation of white smoke of sulfuric acid.
The residue is cooled, rinse the walls of the Cup with water and re-evaporated prior to the allocation of white smoke of sulfuric acid. After cooling, to the residue add 30−40 cmof water and heated to dissolve the salts. After cooling, the solution is transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with water and further analysis are as indicated in claim
3.3.4. Construction of calibration curve
In a separating funnel with a capacity of 150 cmis placed 1,0; 2,0; 4,0; 6,0; 8,0 and 10,0 cm
standard solution of copper, dilute with water to 25 cm
, add 5 cm
of tartaric acid and further analysis are as indicated in claim
3.4. Processing of the results
3.4.1. Mass fraction of copper in percent is calculated by the formula
,
where is the mass of copper was found in the calibration schedule g;
— weight of alloy, suitable aliquote part of the solution,
3.4.2. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.3.
Table 3
3.4.3. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA) or by standard samples of the enterprise (SOP) Nickel alloy, approved by GOST 8.315, or by additives or by comparison of the results obtained by another method in accordance with GOST 25086.
4. POLAROGRAPHIC METHOD FOR THE DETERMINATION OF COPPER
4.1. The essence of the method
The method is based on the polarographic determination of copper without separating from the main alloy components on the wave of recovery of copper (II) on dripping mercuric electrode in hydrochloric acid solution.
4.2. Equipment, reagents, solutions
Polarograph AC-PPT-1 and the cell made of glass with a volume of 30−40 cmwith an external reference electrode (saturated calomel electrode) and mercury dripping electrode. In the absence of device-PPT-1 allowed the use of data handling other brands.
Hydrochloric acid according to GOST 3118, diluted 1:8.
Nitric acid according to GOST 4461, diluted 1:1 and 1% solution.
Sulfuric acid according to GOST 4204.
Hydrofluoric acid according to GOST 10484.
Mercury brands r0 according to GOST 4658, does not contain moisture and purified from the oxide film.
30−50 cmof mercury is transferred from a container into a glass and slowly filtered through a double dry filter medium density, which in the lower part of the filter make a small needle hole. Filtered mercury immediately placed in the pressure capacity of mercury dripping electrode and store in a tightly closed pressure vessel.
Nitrogen gas according to GOST 9293.
Copper of mark M0 or M1 according to GOST 859.
Standard solutions of copper
Solution a: 0.2 g of copper was dissolved with heating in 20 cmof nitric acid (1:1), is removed by boiling oxides of nitrogen, cool, transfer the solution into a volumetric flask with a capacity of 200 cm
and then filled to the mark with water.
1 cmof the solution contains 0.001 g of copper.
Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cm
and then filled to the mark with water.
1 cmof a solution contains 0.0001 g honey
I.
4.3. Analysis
4.3.1. For alloys containing less than 0.1% of silicon and not containing chromium and tungsten
A portion of the alloy (tab.4) is placed in a beaker with a capacity of 250−300 cm, add 15 cm
of nitric acid (1:1), covered with a glass watch glass, glass or plastic plate and dissolved by heating.
Table 4
After dissolution of the alloy or glass plate and the side of the Cup then rinsed with water and the solution is evaporated to 2−3 cm. After cooling, add 20 cm
of hydrochloric acid (1:8), translate the solution into a measuring flask with a capacity of 100 cm
and then filled to the mark with hydrochloric acid (1:8).
4.3.2. For alloys containing tungsten
A portion of the alloy (see table.4) is placed in a beaker with a capacity of 250−300 cm, add 15 cm
of nitric acid (1:1) and dissolved by heating.
After dissolution of the alloy solution is evaporated to a syrupy condition, dilute with water to 150 cm, heated to 60−70 °C and filtered through a dense filter. The filter cake was washed 4−5 times with hot 1% nitric acid solution. The precipitate is discarded. The resulting solution is evaporated to 2−3 cm
and then do as described in section
4.3.3. For alloys containing chromium and more than 0.1% silicon
A portion of the alloy (see table.4) is placed in a platinum Cup, add 20 cmof nitric acid (1:1), 5 cm
hydrofluoric acid and dissolved by heating. The solution was cooled, add 5 cm
of sulphuric acid and evaporated until white smoke of sulfuric acid.
The residue is dissolved in 20 cmof hydrochloric acid (1:8) and then act as described in section
In all cases, through the analysis of spend control experience.
4.3.4. From the flask with a capacity of 100 cmis placed in a polarographic cell aliquot part of the solution (see table.4), was purged with a nitrogen flow of 4−6 min and polarografic when changing the potential from minus 0.10 and minus 0.5 In registering the current recovery of copper at a potential of minus 0.25 to minus 0,35 V.
If aliquota part of the solution is 5 cm, the polarographic cell is placed a pre-15 cm
of hydrochloric acid (1:8).
The height of the recorded waves or a peak must be at least 10 mm when the sensitivity of polarography.
4.3.5. Definition of copper by the method of additives
Aliquot part of the copper solution B (0.1 to 0.3 cm) was added to the cell, and further receives, as described in Chapter
The amount of additives is chosen so that the wave height (peak) of copper increased by approximately 2−3 times compared to the wave height (peak) prior to the introduction of additives.
4.4. Processing of the results
4.4.1. Mass fraction of copper in the alloy in percent is calculated by the formula
,
where is the wave height (peak) of copper for the test solution, mm;
wave height (peak) of copper for the reference experiment, mm.
— the volume of standard addition, cm
;
— the concentration of a standard solution of copper, g/cm
;
wave height (peak) of copper for the analyzed solution with the addition of, mm.
— hanging alloy, taken on polarography,
G.
4.4.2. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.3.
4.4.3. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA) or by standard samples of the enterprise (SOP) Nickel alloy, approved by GOST 8.315, or by additives or by comparison of the results obtained by another method in accordance with GOST 25086.
5. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF COPPER
5.1. The essence of the method
The method is based on the formation of copper ions at pH of 1.0−1.5 complex compounds with pyramid-Epsilon and measuring the optical density of the resulting solution.
5.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461, diluted 3:2, 1:1 and 1:100.
Sulfuric acid according to GOST 4204, diluted 1:1 and a solution of 1 mol/DM.
Hydrofluoric acid according to GOST 10484.
Ascorbic acid, freshly prepared solution of 10 g/DM.
Thiourea according to GOST 6344 solution of 100 g/DM.
Pyramid-Epsilon h. d. a., a solution of 1 g/DM.
Nickel brand H0 according to GOST 849.
A standard solution of Nickel (see preparation in step 2.2).
Copper of mark M0 GOST 859.
Standard solutions of copper
Solution a: 0.1 g of copper is dissolved in 20 cmof nitric acid (1:1), boil to remove oxides of nitrogen, cooled, transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and mix.
1 cmof the solution contains 0.0001 g of copper.
Solution B: 25 cmsolution And placed in a volumetric flask with a capacity of 250 cm
, made up to the mark with water and mix.
1 cmof solution B contains 0,00001 g m
EDI.
5.3. Analysis
5.3.1. For alloys containing less than 0.1% of silicon and not containing chromium and tungsten
A portion of the alloy (tab.5) is placed in a beaker with a capacity of 250 cm, add 15 cm
of nitric acid (1:1), cover with a watch glass or plastic plate and dissolved by heating. After cooling, the glass or the plate and the wall of the beaker rinse with water, add 5 cm
of sulphuric acid (1:1) and the solution is evaporated prior to the allocation of white smoke of sulfuric acid.
Table 5
The residue is cooled, rinse the walls of the glass with water and re-evaporated prior to the allocation of white smoke of sulfuric acid. After cooling, to the residue add 20−30 cmof water and heated to dissolve the salts. After cooling, the solution was transferred to volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix.
Aliquot part of the obtained solution (table.5) is placed in a volumetric flask with a capacity of 50 cm, was added 1 mol/DM
sulfuric acid solution (table.5), 2 cm
of ascorbic acid solution, 2 cm
of mortar pyramid-Epsilon, made up to the mark with water and mix. The optical density measured on a spectrophotometer at 550 nm or photoelectrocolorimeter with a yellow filter in cell 2 or 5 cm depending on the mass fraction of copper in the alloy. Solution comparison is the solution of the same sample which is injected 2 cm
of a solution of thiourea prior to adding pyramid-Epsilon
.
5.3.2. For alloys containing tungsten
A portion of the alloy (see table.5) is placed in a beaker with a capacity of 250 cm, add 15 cm
of nitric acid (3:2), cover with a watch glass or plastic plate and dissolved by heating. Glass or plate and the side of the Cup then rinsed with water and the solution is evaporated to a syrupy condition. To the residue add 25−30 cm
of hot water, heated to 60−70 °C and the precipitate tungsten acid is filtered off on a tight filter, carefully washed the beaker and the precipitate with nitric acid (1:100). The precipitate is discarded. The filtrate is evaporated to 40−50 cm
, after cooling, add 5 cm
of sulphuric acid (1:1), evaporated prior to the allocation of white smoke of sulfuric acid and further analysis are as indicated in claim
5.3.3. For alloys containing more than 0.1% of silicon and chromium
A portion of the alloy (see table.5) is placed in a platinum Cup, add 15 cmof nitric acid (3:2), 3 cm
hydrofluoric acid and dissolved by heating. After cooling, add 5 cm
of sulphuric acid (1:1) and the solution is evaporated prior to the allocation of white smoke of sulfuric acid.
The residue is cooled, rinse the walls of the Cup with water and re-evaporated prior to the allocation of white smoke of sulfuric acid. After cooling, to the residue add 20−30 cmof water and heated to dissolve the salts. After cooling, the solution was transferred to volumetric flask with a capacity of 50 cm
, made up to the mark with water and further analysis are as indicated in claim
5.3.4. Construction of calibration curve
In a volumetric flask with a capacity of 50 cmis placed 3 cm
standard Nickel solution, add 0,2; 0,4; 0,6; 0,8 and 1,0 cm
standard solution B copper (at a mass fraction of copper from 0.005 to 0.02%) or 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cm
standard solution B copper (at a mass fraction of copper from 0.02 to 0.6%). Then add 2 cm
of sulphuric acid (1 mol/DM
) and further analysis are as indicated in claim
The optical density of solutions measured in 5 cm cell (when the mass fraction of copper from 0.005 to 0.02%) or 2 cm (mass fraction of copper from 0.02 to 0.6%).
Solution comparison is the solution not containing copper. According to the obtained results build a calibration curve.
5.4. Processing of the results
5.4.1. Mass fraction of copper in percent is calculated by the formula
,
where is the mass of copper was found in the calibration schedule g;
— the weight of the portion of alloy, suitable aliquote part of the solution,
5.4.2. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.3.
5.4.3. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) Nickel alloy, approved by GOST 8.315 or by additives or by comparison of the results obtained by another method in accordance with GOST 25086.
6. ATOMIC ABSORPTION METHOD FOR DETERMINATION OF COPPER
6.1. The essence of the method
The method is based on measuring the absorption of light by atoms of copper produced during the introduction of the analyzed solution in the flame acetylene-air.
6.2. Apparatus, reagents and solutions
Atomic absorption spectrometer with a source of radiation for copper.
Nitric acid according to GOST 4461, diluted 1:1 and 1:100.
Hydrofluoric acid according to GOST 10484.
Sulfuric acid according to GOST 4204, diluted 1:1.
Copper according to the GOST 859.
The copper solution: 0.1 g of copper was dissolved with heating in 10 cmof nitric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 1 DM
and topped to the mark with water.
1 cmof the solution contains 0.0001 g of copper.
Nickel GOST 849.
The solution of Nickel: 10 g of Nickel is dissolved by heating in 80 cmof nitric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 100 cm
and top up with water to the mark.
1 cmof the solution contains 0.1 g of Nickel.
6.3. Analysis
A sample of alloy weighing 1 g is taken to determine the mass fraction of copper of 0.005−0.1% by weight of 0.1 g to determine the mass fraction of copper of 0.1−0.6 percent.
6.3.1. For alloys not containing silicon, chromium, tungsten and titanium
A portion of the alloy is dissolved by heating in 10 cmof nitric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 100 cm
and top up with water to the mark.
Measure the atomic absorption of copper in the flame acetylene-air at a wavelength of 324,7 nm parallel to the calibration solutions.
6.3.2. For alloys containing silicon, titanium and chromium
A portion of the alloy placed in a platinum Cup and dissolved by heating in 10 cmof nitric acid (1:1) and 2 cm
hydrofluoric acid. Then add 10 cm
sulphuric acid (1:1) and evaporated until a white smoke of sulfuric acid. Cup cooled and the residue is dissolved in 50 cm
of water when heated. The solution was transferred to a volumetric flask with a capacity of 100 cm
and top up with water to the mark. Measure the atomic absorption of copper, as specified in clause
6.3.3. For alloys containing tungsten
A portion of the alloy is dissolved by heating in 10 cmof nitric acid (1:1), then add 30 cm
of hot water and the precipitate tungsten acid is filtered off on a tight filter and washed with hot nitric acid (1:100). The filtrate is transferred to a volumetric flask with a capacity of 100 cm
and top up with water to the mark. Measure the atomic absorption of copper, as specified in clause
6.3.4. Construction of calibration curve
In six of the seven volumetric flasks with a capacity of 100 cmis placed 0,5; 2,0; 4,0; 6,0; 8,0 and 10,0 cm
standard solution of copper, which corresponds to 0,05; 0,2; 0,4; 0,6; 0,8 and 1,0 mg of copper. All flasks is poured 10 cm
of nitric acid (1:1). When the mass fraction of copper is less than 0.1% is added to 10 cm
of a solution of Nickel and topped to the mark with water. Measure the atomic absorption of copper, as specified in clause
6.4. Processing of the results
6.4.1. Mass fraction of copper in percent is calculated by the formula
,
where is the concentration of copper was found in the calibration schedule, g/cm
;
— the volume of the sample solution, cm
;
— the weight of the portion of the sample,
6.4.2. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.3.
6.4.3. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) Nickel alloy, approved by GOST 8.315, or by additives or by comparison of the results obtained by another method in accordance with GOST 25086.