GOST 24018.1-80
GOST 24018.1−80 heat-resistant Alloys on a Nickel basis. Methods for determination of tin (with Amendments No. 1, 2)
GOST 24018.1−80
Group B39
INTERSTATE STANDARD
ALLOYS HIGH-TEMPERATURE NICKEL-BASED
Methods for determination of tin
Nickel-based fire-resistant alloys.
Methods for the determination of tin
ISS 77.120.40
AXTU 0809
Date of introduction 1981−07−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. INTRODUCED FOR THE FIRST TIME
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
The number of the paragraph, subparagraph |
| GOST 849−97 |
2.2, 5.2 |
| GOST 860−75 |
2.2, 3.2, 4.2, 5.2 |
| GOST 3118−77 |
2.2, 3.2, 4.2, 5.2 |
| GOST 3760−79 |
2.2, 3.2, 4.2, 5.2 |
| GOST 3773−72 |
4.2 |
| GOST 4204−77 |
Of 2.2, 3.2, 4.2, 5.2 |
| GOST 4233−77 |
3.2 |
| GOST 4328−77 |
3.2 |
| GOST 4461−77 |
2.2, 3.2, 4.2, 5.2 |
| GOST 4658−73 |
3.2, 4.2 |
| GOST 9293−74 |
3.2, 4.2 |
| GOST 9722−97 |
2.2, 3.2, 4.2, 5.2 |
| GOST 10157−79 |
3.2, 4.2, 5.2 |
| GOST 10652−73 |
2.2, 3.2, 4.2, 5.2 |
| GOST 10929−76 |
5.2 |
| GOST 11125−84 |
2.2, 3.2, 4.2, 5.2 |
| GOST 14261−77 |
2.2, 3.2, 4.2, 5.2 |
| GOST 14262−78 |
2.2, 3.2, 4.2, 5.2 |
| GOST 22180−76 |
4.2 |
| GOST 24018.0−90 |
1.1 |
| GOST 24147−80 |
2.2, 4.2 |
5. Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)
6. EDITION (August 2004) with Changes No. 1, 2 approved in December 1985, December 1990 (IUS 4−86, 3−91)
This standard sets the photometric method for the determination of tin (in mass fractions of from 0.001% to 0,010%) in the alloys containing no niobium and titanium, polarographic method for the determination of tin (in mass fractions of from 0.001% to 0,010%) and Stripping voltammetric method for the determination of tin (in mass fractions of from 0.0001% to 0.005%) and flameless atomic absorption method for the determination of tin (at a mass fraction of from 0.0002% to 0,010%).
(Changed edition, Rev. N 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 24018.0.
2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF TIN IN ALLOYS CONTAINING NO NIOBIUM AND TITANIUM
2.1. The essence of the method
The method is based on formation of blue coloured complex compounds of tin (IV) with pyrocatechin purple stabilized with gelatin. Light absorption of the solution measured at 
2.2. Apparatus, reagents and solutions
Spectrophotometer or photoelectrocolorimeter.
a pH meter.
Hydrochloric acid according to GOST 3118, GOST 14261 and diluted 1:1.
Nitric acid according to GOST 4461, GOST 11125.
Sulfuric acid according to GOST 4204, GOST 14262 and diluted 1:4.
Ammonia water according to GOST 3760, GOST 24147 and diluted 1:100.
Beryllium nitrate, an aqueous solution with a mass concentration of 20 g/cm, (g/DM
).
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid, 2-water (Trilon B) according to GOST 10652, a solution with a mass concentration of 10 g/cm, (g/DM
).
Ascorbic acid, food, a solution with a mass concentration of 1 g/cm(g/DM
).
Pyrocatechin purple, 0.001 mol/DMsolution: 0,4324 g pyrocatechin violet dissolved in water, transferred to a volumetric flask with a capacity of 1 DM
, made up to the mark with water, mix.
Food gelatin solution with mass concentration of 0.5 g/cm(g/DM
).
Nickel brand H0 according to GOST 849.
Powder Nickel brand PNK-UT1-UT4 according to GOST 9722.
Tin brands ОВч000, 01, 01 PCH, GOST 860.
Standard solutions of tin.
Solution a: 0.1 g of tin are dissolved in 20 cmof sulphuric acid when heated. The solution was transferred to a volumetric flask with a capacity of 1 DM
solution of sulphuric acid, diluted 1:4, cooled, made up to the mark with this same solution and mix.
1 cmstandard solution contains 0.0001 g of tin.
Solution B: 10 cmstandard solution And transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with sulfuric acid solution, diluted 1:4, mix, prepared immediately before use.
1 cmstandard solution B contains 0,00001 g tin.
(Redrafted From
M. N 1, 2).
2.3. Analysis
2.3.1. A sample of alloy weighing 0.5 g were placed in a glass or flask with a capacity of 250−300 cm, flow 15 cm
of hydrochloric acid and 5 cm
of nitric acid, 7 cm
of sulfuric acid, cover the beaker or the flask with a watch glass and dissolve the sample when heated. After dissolution, the sample solution is evaporated to release vapors of sulfuric acid. Salt is dissolved in 40 cm
of water when heated. To the solution was added to 7−10 cm
of ammonia solution with stirring, poured 50 cm
of the solution Trilon B solution and boil for 10−15 min.
Add 3 cmof a solution of beryllium nitrate, ammonia solution before precipitation of hydroxides of metals and an excess of 1−2 cm
. Solution and the precipitate was heated at 70 °C — 80 °C for 10 minutes, bringing it to a boil. The beaker with contents is cooled in running water or at 15 °C — 20 °C for 45−60 min. the Precipitate was filtered off on a medium density filter (white ribbon) and washed 5−7 times with hot dilute ammonia solution (1:100). The filtrate is discarded. The precipitate from the filter washed with hot water in a glass or flask, which carried out the precipitation of hydroxide of metals. The filter is washed with 20 cm
of sulphuric acid (1:4) and 2 times with hot water. The solution was evaporated to approximately 10 cm
, flow 50 cm
of the Trilon B solution and heated for 5 min. Then pour the ammonia solution before precipitation of hydroxides of metals and an excess of 1−2 cm
. Solution and the precipitate was boiled for 1−2 min. the Precipitate was filtered off on a medium density filter (white ribbon) and washed 5−7 times with hot dilute ammonia solution (1:100). The filtrate is discarded. The precipitate from the filter washed with hot water in a glass or flask, which carried out the precipitation of hydroxide of metals. The filter is washed with 20 cm
of sulphuric acid (1:4), 2 times with hot water and discarded. To the filtrate add 5−7 cm
of nitric acid and the solution was evaporated to wet salts. Wash the walls of the beaker or flask with water and again evaporated to moist salts. Salt is dissolved in 10 cm
water when it is heated, cooled. The solution was transferred to a beaker with a capacity of 100 cm
, pour 1 cm
of ascorbic acid solution, mix and set pH to 2.2 with a solution of ammonia using pH meter. The solution is poured 1 cm
of solution of gelatin, 1.5 cm
pyrocatechin purple solution and stirred solution. After 20 min the solution was transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark with water, mix and measure the optical density of the solution on the spectrophotometer at
Mass of tin find the calibration schedule subject to amendments the reference experiment.
2.3.2. Construction of calibration curve
Seven of cups or flasks with a capacity of 250−300 cmis placed 0.5 g of metallic Nickel. Six of cups or flasks poured consistently 0,5; 1; 2; 3; 4; 5 cm
standard solution B. the Seventh beaker or flask used for the control experience. All beakers or flasks poured 15 cm
of hydrochloric acid and 5 cm
of nitric acid, 7 cm
of sulfuric acid, cover the cups or flasks watch glass and dissolve the sample when heated. Then do as stated in claim
From the values of optical density of analyzed solutions is subtracted the value of optical density in the reference experiment. The found values of optical density and corresponding values of the mass of tin to build a calibration curve.
2.3.1,
2.4. Processing of the results
2.4.1. Mass fraction of tin () in percent is calculated by the formula
where — weight of tin, was found in the calibration schedule g;
— the weight of the portion of alloy,
2.4.2. The absolute differences of the results of the parallel definitions should not exceed (at p = 0.95) of permissible values, specified in table.3b.
(Changed edition, Rev. N 2).
3. POLAROGRAPHIC METHOD FOR THE DETERMINATION OF TIN
3.1. The essence of the method
The method is based on the ability to recover tin on dripping mercuric electrode at a potential of minus peak of 0.48 In a relatively mercury anode in the background of 2 mol/DMHcl, and 3 mol/DM
NaCl. Tin pre-separates the ammonia from the main alloy components of beryllium hydroxide in the presence of Trilon B. in the determination of tin in alloys containing more than 1% titanium, will spend an additional separation of tin from titanium by the sodium hydroxide solution. Mode polarographically — alternating-current or oscilloscope.
3.2. Apparatus, reagents and solutions
Polarograph AC or polarograph oscilloscope. The polarographic cell, made of glass with anode (bottom mercury) and mercury-drip cathode attached to polarography.
Mercury brand P1 according to GOST 4658 containing no moisture.
Nitrogen gas according to GOST 9293 or argon according to GOST 10157.
Hydrochloric acid according to GOST 3118, GOST 14261.
Nitric acid according to GOST 4461, GOST 11125.
Sulfuric acid according to GOST 4204, GOST 14262, diluted 1:4.
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid, 2-water (Trilon B) according to GOST 10652, with a mass concentration of 10 g/cm, (g/DM
).
Beryllium nitrate, an aqueous solution of 0.08 g/cm.
Ammonia water according to GOST 3760 and diluted 1:50.
Sodium hydroxide according to GOST 4328, a solution with a mass concentration of 20 g/cm, (g/DM
).
Sodium chloride according to GOST 4233.
Tin GOST 860, brand 01.
Standard solutions of tin.
Solution a: 0.1 g of tin are dissolved in 20 cmof sulphuric acid when heated. The solution was transferred to a volumetric flask with a capacity of 1 DM
, with a sulfuric acid solution, diluted 1:4, cooled, made up to the mark with this same solution and mix.
1 cmstandard solution contains 0.0001 g of tin.
Solution B: 10 cmstandard solution And transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with sulfuric acid solution diluted 1:4 and stirred, were prepared immediately before use.
1 cmstandard solution B contains 0,00001 g tin.
(Changed edition, Rev. N 1
, 2).
3.3. Analysis
3.3.1. A sample of alloy weighing 0.5 g were placed in a glass or flask with a capacity of 250−300 cm, flow 15 cm
of hydrochloric acid and 5 cm
of nitric acid, 2cm
of sulfuric acid, cover the beaker or the flask with a watch glass and dissolve the sample when heated. The solution was evaporated to a volume of approximately 10 cm
, flow 50 cm
of the solution Trilon B, 5 cm
of a solution of beryllium nitrate and heated for 5 min. Then pour the ammonia solution before the precipitation of hydroxides of metals and an excess of 1−2 cm
. Solution and the precipitate was boiled for 1−2 min, remove beaker or flask from heat and sediment to settle for 1 h. the Precipitate was filtered off on a medium density filter «white ribbon» and washed 5−7 times with a weak solution of ammonia, the filtrate discarded. The precipitate from the filter washed with a dilute solution of ammonia into a glass, which was carried out the precipitation of the hydroxides of the metals. The filter is washed with 20 cm
of sulphuric acid (1:4) and 2 times with hot water. To the solution was added 3 cm
of nitric acid and evaporate the solution to wet salts.
When the mass fraction of titanium in the alloy is less than 1% of salt is dissolved in 10 cmwater when it is heated, add 9 cm
of hydrochloric acid and 9 g of sodium chloride transfer the contents of the Cup into a measuring flask with a capacity of 50 cm
, made up to the mark with water and mix.
When the mass fraction of titanium in the alloy more than 1% of salt is dissolved in 10 cmwater when it is heated, add 20 cm
of sodium hydroxide solution and again heated for 2 min. Then the solution and the precipitate was transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix. The solution is filtered over a dry filter medium density «white ribbon» in the dry glass. Take 25 cm
of filtrate into a measuring flask with a capacity of 50 cm
, was added 12 cm
of hydrochloric acid, 4.2 g sodium chloride, made up to the mark with water and mix.
The solution is purged with nitrogen or argon for 5 min and remove polarogram from minus 0.2 to minus 0.8 V, recording the peak recovery of tin at a minus of 0.48 V. the Sensitivity of the device are selected so that the height of the peak recovery of tin was at least 10 mm.
The mass of tin in the test solution is determined by gruberova
nome schedule.
3.3.2. Construction of calibration curve
In beakers or flasks with a capacity of 250−300 cmis placed 0,5; 1; 2; 4; 5 cm
standard solution B, and poured in 15 cm
of hydrochloric acid and 5 cm
of nitric acid, 2cm
of sulfuric acid and then the solutions is carried out through all stages of analysis, as specified in clause
The value of the peak height reference experiment is subtracted from the value of the peak height of the investigated solution.
3.3.1,
3.4. Processing of the results
3.4.1. Mass fraction of tin () in percent is calculated by the formula
where — weight of tin, was found in the calibration schedule g;
— the weight of the portion of the alloy or the weight of the portion of alloy, suitable aliquote part of the solution with mass fraction of titanium is more than 1%.
3.4.2. The absolute differences of the results of the parallel definitions should not exceed (at p = 0.95) of permissible values, specified in table.3A.
(Changed edition, Rev. N 2).
4. INVERSION-VOLTAMMETRIC METHOD FOR DETERMINATION OF TIN
4.1. The essence of the method
The method is based on the preconcetration of tin on a stationary mercury drop electrode at a potential of minus 0.75 V relative to silver chloride electrode or a minus 0.9 volts relative to the mercury anode in the solution of 0.5 mol/loxalic acid and 1·10
mol/DM
methylene blue with subsequent registration of the current of anodic dissolution of tin at a potential of minus 0.54 relative to silver chloride electrode or a minus 0,73 In relation to the mercury anode. Tin pre-separates the ammonia from the main alloy components of beryllium hydroxide in the presence of Trilon B.
(Changed edition, Rev. N 1).
4.2. Apparatus, reagents and solutions
Polarograph AC, oscilloscope or DC. The polarographic cell with anode (bottom mercury) or with an external anode (mercury in a saturated solution of potassium chloride), silver chloride reference electrode and a stationary mercury drop electrode of any design, providing the required accuracy of reproducibility of the analytical signal.
Mercury brands r0 according to GOST 4658 containing no moisture.
Nitrogen gas according to GOST 9293 or argon according to GOST 10157.
Hydrochloric acid according to GOST 14261 or GOST 3118 and diluted 1:1.
Nitric acid according to GOST 11125 or GOST 4461.
Sulfuric acid according to GOST 14262 or GOST 4204, diluted 1:4.
Ammonia water according to GOST 24147, GOST 3760 and diluted 1:50.
Ammonium chloride according to GOST 3773.
Beryllium nitrate, an aqueous solution of 0.08 g/cm.
Disodium salt, Ethylenediamine-N, N, N', N'-tetraoxane acid, 2-water (Trilon B), GOST-10652, a solution with a mass concentration of 10 g/cm, (g/DM
).
Oxalic acid according to GOST 22180, solutions 1 mol/land 0.5 mol/DM
.
Methylene blue aqueous solution with a mass concentration of 15 g/cm, (g/DM
).
Tin stamps 01 according to GOST 860.
Standard solutions of tin.
Solution a: 0.1 g of tin are dissolved in 20 cmof sulphuric acid when heated. The solution was transferred to a volumetric flask with a capacity of 1 DM
solution of sulphuric acid, diluted 1:4, cooled, made up to the mark with this same solution and mix.
1 cmstandard solution contains 0.0001 g of tin.
Solution B: 10 cmstandard solution And transferred to a volumetric flask with a capacity of 100 cm
and then filled to the mark with sulfuric acid solution, diluted 1:4, and stirred.
1 cmstandard solution B contains 0,00001 g tin.
Solution: 5 cmstandard solution B is transferred to a volumetric flask with a capacity of 50 cm
and then filled to the mark with water and mix.
1 cmstandard solution contains 0,000001 g tin.
Solutions B and C were prepared immediately before use.
(Revised edition, Edit
. N 1, 2).
4.3. Analysis
4.3.1. A sample of alloy weighing 0.5 g were placed in a glass or flask with a capacity of 250−300 cm, flow 15 cm
of hydrochloric acid and 5 cm
of nitric acid, 2 cm
of sulphuric acid and dissolve the sample when heated. After dissolution, the sample solution was evaporated to approximately 10 cm
, flow 50 cm
of the solution Trilon B, 5 cm
of a solution of beryllium nitrate and heated for 5 min. Then pour the ammonia solution before the precipitation of hydroxides of metals and an excess of 1−2 cm
. Solution and the precipitate was boiled for 1−2 min, remove beaker or flask from heat and sediment to settle for 1 h.
The precipitate was filtered off on a medium density filter «white ribbon», washed 5−7 times in hot water, the filtrate discarded. The precipitate from the filter washed with a dilute solution of ammonia into a glass, which was carried out the precipitation of the hydroxides of the metals, the filter is washed with 20 cmof sulphuric acid (1:4) and 2 times with diluted ammonia solution. To the solution was added 3 cm
of nitric acid and evaporate the solution to wet salts. Salt is dissolved in 10 cm
water when it is heated, add 25 cm
of solution of 1 mol/l
of oxalic acid, transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix.
For the determination of tin in polarographic flow cell 20 cmof a solution of 0.5 mol/l
of oxalic acid, previously purged with nitrogen or argon for 5 min, 0.5 cm
of methylene blue, aliquot part of the study solution (table.3) depending on the assumed mass fraction of tin in the alloy.
Table 3*
________________________________
* Table.1, 2, 4. (Deleted, Rev. N 2).
| Mass fraction of tin, % |
The volume aliquote part of the solution, cm |
Weight of alloy, suitable aliquote part of the solution, g |
| From 0.0001 to 0.0005 to |
2 |
0,02 |
| SV. Of 0.0005 «to 0.001 |
1 |
0,01 |
| «To 0.001» 0,0025 |
1 |
0,01 |
| «Of 0.0025» to 0.005 |
0,5 |
0,005 |
Set on polarography potential minus or minus 0.75 V 0.9 V relative to silver chloride electrode or bottom of mercury respectively, and hold the concentration of tin on a stationary mercury drop electrode in a continuously stirred solution for 1 min. At the end of the accumulation time, stop stirring and allow solution to settle down 15, and then remove the anodic polarization curve with linearly varying electrode potential of minus 0.2 V, registering a peak of dissolution of tin in minus or minus 0.54 to 0.73 In relative to silver chloride electrode or the bottom of the mercury. The sensitivity of the instrument is selected so that the height of the recorded peak was at least 10 mm. For each dimension, get a new drop of mercury.
(Changed edition, Rev. N 1).
4.3.2. The tin content find by the method of standard additions. Aliquot part of the standard solution added to the test solution, stirred for 1 min and further lead to the accumulation of tin, as stated in claim 4.3.1 when determining the content of tin in the test solution.
The value of the standard additives are selected so that the height of the peak of tin after the introduction of the additive increased 1.5−2 times.
4.4. Processing of the results
4.4.1. Mass fraction of tin () in percent is calculated by the formula
where is the height of the peak of tin in polarography of test solution, mm;
— the height of the peak of tin in polarography solution in the reference experiment, mm.
— the height of the peak of tin after the introduction into a cell of standard addition, mm;
— the volume of standard addition, cm
;
— concentration of standard solution, g/cm
;
— the weight of the portion of alloy, suitable aliquote part of the solution
G.
4.4.2. The absolute discrepancies in the results of parallel measurements (at p = 0.95) must not exceed the permissible values given in table.3b.
(Changed edition, Rev. N 2).
5. FLAMELESS ATOMIC ABSORPTION METHOD FOR DETERMINATION OF TIN
5.1. The essence of the method
The method is based on measuring absorption of radiation by free atoms of tin at a wavelength of 286,3 nm, formed with the introduction of the analyzed solution in the electrothermal atomizer. Tin is pre-separated from the main components of the alloy by precipitation in the form of hydroxide with ammonia in the presence of Trilon B as complexing agents and with the use of the collector of the hydroxide of beryllium.
5.2. Apparatus, reagents and solutions
Atomic absorption spectrophotometer with electrothermal atomizer.
Lamp for determination of tin.
Argon of high purity according to GOST 10157.
A mixture of argon with 5% hydrogen.
Hydrochloric acid according to GOST 3118, GOST 14261.
Nitric acid according to GOST 4461, GOST 11125 and diluted 1:1.
Sulfuric acid according to GOST 4204, GOST 14262 and diluted 1:4.
A mixture of hydrochloric and nitric acids (150 cmof hydrochloric acid and 50 cm
of nitric acid), prepared immediately before use.
Ammonia water according to GOST 3760, GOST 24147 and diluted 1:100.
Hydrogen peroxide according to GOST 10929.
Beryllium nitrate, a solution of 200 g/DM.
Salt is the disodium Ethylenediamine — N, N, N', N
' -tetraoxane acid 2-water (Trilon B) according to GOST 10652, a solution of 100 g/DM
.
Nickel brand H0 according to GOST 849.
Powder Nickel brand PNK-UT1-UT4 according to GOST 9722.
Tin brands Ovch 000, 01, 01пч according to GOST 860.
Standard solutions of tin.
Solution a: 0.1 g of tin are dissolved in 20 cmof sulphuric acid when heated. The solution was transferred to a volumetric flask with a capacity of 1 DM
sulfuric acid 1:4, cooled, made up to the mark with this same solution and mix. 1 cm
standard solution contains 0.0001 g of tin.
Solution B: 10 cmstandard solution And transferred to a volumetric flask with a capacity of 100 cm
, top up to the mark with sulphuric acid 1:4 and stirred. 1 cm
standard solution B contains 0,00001 g tin.
Solution: 5 cmstandard solution B is transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark with sulphuric acid 1:4 and stirred. 1 cm
standard solution contains 0,000001 g tin.
Solutions B and C were prepared immediately before use
use.
5.3. Analysis
5.3.1. The weight of the alloy (tab.3A) were placed in a glass or flask with a capacity of 250−300 cm, flow 20 cm
of a mixture of hydrochloric and nitric acids, 7 cm
of sulfuric acid, cover the beaker watch glass and dissolve the sample when heated. The solution was evaporated prior to the allocation of sulfuric acid vapor, is cooled.
Table 3A
| Mass fraction of tin, % |
The mass of charge, g |
| From of 0.0002 to 0.002 incl. |
0,5 |
| SV. Of 0.002 «to 0.005 « |
0,2 |
| «0,005» 0,01 « |
0,1 |
Salt dissolved in 40−50 cmof water when it is heated, cooled. To a solution pour 7−10 cm
of ammonia, with stirring, 50 cm
of the solution Trilon B solution and boil for 10−15 min. Add 1 cm
of a solution of beryllium nitrate, ammonia until the precipitation of metal hydroxides and excess of 1−2 cm
. Solution and the precipitate was heated at 70 °C — 80 °C for 10 minutes, bringing it to a boil, and cooled in running water or at 15 °C — 20 °C for 1 h. the Precipitate was filtered off on a medium density filter (white ribbon) and washed 5−7 times with hot dilute ammonia. The filtrate is discarded. The precipitate from the filter washed with hot water in a glass or flask, which carried out the deposition of metal hydroxides.
The filter is washed with 15 cmof nitric acid (1:1) and 2 times with hot water. The filter is discarded. The contents of the beaker evaporated to wet salts. Salt is dissolved in 10 cm
of nitric acid (1:1) by heating under glass.
In the analysis of alloys containing titanium and niobium salt is dissolved in 10 cmof nitric acid (1:1) and 10 cm
of hydrogen peroxide when heated under the glass. The solution was transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark with water, mix. Take a micropipette aliquot part of the solution 20 micysmf
, put her in electrothermal atomizer and record the amount of radiation absorption by using a registered device. For measurements taken at least three alikvotnih parts of the solution.
Mass of tin find on a calibration schedule, as amended by the control of
trying.
5.3.2. Preparation of the device for measuring
Activation of the device, setting the spectrophotometer at the resonant radiation, the adjustment of the control unit, block, atomization is carried out according to the instructions supplied with the device.
Conditions for determination of tin:
analytical line () — 286,3 nm;
— the spectral slit width of 0.2 nm;
— drying time at 120 °C — 30 s;
— the decomposition at 1100 °C — 30 s;
— time atomization at 2700 °C — 5 s.
The definition of tin is carried out in the full flow of inert gas with disabling it on stage atomization.
5.3.3. Construction of calibration curve
Seven of cups or flasks with a capacity of 250−300 cmis placed 0.5 g of metallic Nickel or of Nickel powder at the mass fraction of tin from from 0.0002% to 0.002%, 0.2 g of metallic Nickel or of Nickel powder at the mass fraction of tin in excess of 0.002% to 0.005% or 0.1 g of metallic Nickel or of Nickel powder at the mass fraction of tin in excess of 0,005%.
Six of cups or flasks poured consistently 1, 2, 4, 6, 8, 10 cmstandard solution Into the tin. The seventh beaker or flask serves for the control experience. All beakers or flasks poured 20 cm
of a mixture of hydrochloric and nitric acids, for 7 cm
of sulfuric acid, cover the cups or flasks, watch glass, and dissolve a sample of metallic Nickel or of Nickel powder when heated.
Then do as specified in clause
From the values of absorbance of analyzed solutions is subtracted the value of optical density in the reference experiment. The found values of optical density and corresponding mass of tin to build a calibration curve.
5.4. Processing of the results
5.4.1. Mass fraction of tin () in percent is calculated by the formula
where — weight of tin, was found in the calibration schedule g;
— the weight of the portion of alloy,
5.4.2. The absolute differences of the results of the parallel definitions should not exceed (at p = 0.95) of permissible values, specified in table.3b.
Table 3b
| Mass fraction of tin, % |
The absolute allowable difference, % |
| 0.0001 0.0002 incl. |
0,0001 |
| SV. Of 0.0002 «to 0.0005 « |
0,0002 |
| «Of 0.0005» to 0.001 « |
0,0005 |
| «Of 0.001» to 0.002 « |
0,001 |
| «Of 0.002» to 0.005 « |
0,002 |
| «0,005» 0,01 « |
0,003 |
Section 5. (Added, Rev. N 2).
