GOST 1652.5-77
GOST 1652.5−77 Alloys copper-zinc. Methods for determination of tin (with Amendments No. 1, 2, 3, 4)
GOST 1652.5−77
Group B59
STATE STANDARD OF THE USSR
ALLOYS COPPER-ZINC
Methods for determination of tin
Copper-zinc alloys. Methods for the determination of tin
AXTU 1709
Date of introduction 1978−07−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
Y. F. Chuvakin, M. B. Taubkin, A. A. Nemodruk, N. In. Egiazarov (supervisor), I. A. Vorobyev
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. REPLACE GOST 1652.5−71
4. The standard fully complies with ISO 4751−84*
________________
* Access to international and foreign documents referred to here and hereinafter, can be obtained by clicking on the link to the site shop.cntd.ru. — Note the manufacturer’s database.
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
The number of the paragraph, subparagraph |
| GOST 8.315−91 |
2.4.4, 3.4.4, 4.4.4 |
| GOST 200−76 |
4.2 |
| GOST 435−77 |
6.2 |
| GOST 859−78 |
2.2, 6.2 |
| GOST 860−75 |
2.2, 3.2, 5.2, 6.2 |
| GOST 1020−77 |
Chapeau |
| GOST 1089−82 |
4.2 |
| GOST 1652.1−77 |
1.1 |
| GOST 2603−79 |
4.2, 5.2 |
| GOST 3118−77 |
2.2, 3.2, 4.2, 6.2 |
| GOST 3640−79 |
6.2 |
| GOST 3652−69 |
5.2 |
| GOST 3760−79 |
2.2, 3.2, 4.2, 5.2, 6.2 |
| GOST 3773−72 |
4.2 |
| GOST 3778−77 |
4.2 |
| GOST 4147−74 |
2.2, 4.2 |
| GOST 4159−79 |
4.2 |
| GOST 4166−77* | 2.2 |
_______________ * Probably a mistake of the original. Should read: GOST 4166−76. — Note the manufacturer’s database. | |
| GOST 4201−79 |
4.2 |
| GOST 4204−77 |
3.2, 4.2, 5.2 |
| GOST 4232−74 |
4.2 |
| GOST 4233−77 |
2.2 |
| GOST 4416−94 |
4.2 |
| GOST 4461−77 |
2.2, 3.2, 4.2, 5.2, 6.2 |
| GOST 6006−78 |
2.2 |
| GOST 6008−90 |
6.2 |
| GOST 6344−73 |
2.2 |
| GOST 9293−74 |
3.2 |
| GOST 10163−76 |
4.2 |
| GOST 10484−78 |
5.2 |
| GOST 10652−73 |
3.2 |
| GOST 10929−76 |
2.2, 3.2, 5.2, 6.2 |
| GOST 11069−74 |
4.2 |
| GOST 15527−70 |
Chapeau |
| GOST 17711−93 |
Chapeau |
| GOST 18300−87 |
5.2, 6.2 |
| GOST 20490−75 |
6.2 |
| GOST 25086−87 |
1.1, 2.4.4, 3.4.4, 4.4 |
6. Resolution of the state standard from
7. REVISED (June 1997) with Amendments No. 1, 2, 3, 4, approved in October 1981 and November 1987, October 1989 and December 1992 (IUS 12−81, 2−88, 2−90, 3−93)
This standard establishes photometric methods for determination of tin (with mass fraction of tin from 0.001 to 0.7% and from 0.005 to 0.5%), a polarographic method for the determination of tin (with mass fraction of tin from 0.001 to 0.5%), atomic absorption method for the determination of tin (with mass fraction of tin from 0.005 to 3%) and titrimetric method for the determination of tin (with tin mass fraction of from 0.05 to 5%) in copper-zinc alloys according to GOST 15527, GOST and GOST 17711 1020.
The standard fully complies with ISO 4751.
(Changed edition, Rev. N 2, 3).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 25086 with the Supplement according to claim 1.1 GOST 1652.1.
(Changed edition, Rev. N 2).
2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF TIN WITH QUERCETIN
2.1. The essence of the method
The method is based on formation of colored complex compounds of tin with quercetin extracted n-butyl alcohol hydrochloric acid solution. Preventing the influence of copper and iron can be eliminated by addition of thiourea.
2.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Hydrochloric acid according to GOST 3118 and diluted 1:1, 1:4 and 1:10.
Nitric acid according to GOST 4461.
Acids mixture: mix three parts hydrochloric acid and one part nitric acid.
Iron chloride according to GOST 4147, a solution of 10 g/DM.
Hydrogen peroxide according to GOST 10929, 30% solution.
Ammonia water according to GOST 3760 and diluted 1:1.
Thiourea according to GOST 6344, solution 100 g/DM.
Sodium chloride according to GOST 4233.
Sodium sulphate anhydrous according to GOST 4166.
Normal butyl alcohol according to GOST 6006.
Quercetin, a solution of 0.4 g/lin n-butyl alcohol.
Copper according to GOST 859 marks M0.
A standard solution of copper, prepared as follows: 2.5 g of copper is dissolved in 30 cmof hydrochloric acid, adding dropwise hydrogen peroxide. The excess hydrogen peroxide is decomposed by boiling, and the solution transferred to a volumetric flask with a capacity of 250 cm
, made up to the mark with water and mix.
1 cmof the solution contains 0.01 g of copper.
Tin GOST 860 stamps O1.
Standard solutions of tin
Solution A, prepared as follows: 0.1 g of tin are placed in a conical flask with a capacity of 100 cm, are added 1 g of sodium chloride, 20 cm
of concentrated hydrochloric acid, 1 cm
of hydrogen peroxide (gradually drop by drop) and heated at 60−70 °C. By the end of the dissolution, the temperature was raised to 80 °C. the Solution was cooled, transferred to a volumetric flask with a capacity of 1 DM
, is poured with hydrochloric acid diluted 1:10, up to the mark and mix.
1 cmof the solution contains 0.0001 g of tin.
Solution B is prepared as follows: 25 cmsolution And transferred to a volumetric flask with a capacity of 250 cm
, made up to the mark with hydrochloric acid diluted 1:10, and stirred.
1 cmof solution B contains 0,00001 g tin. Solution B is prepared on the day of application.
2.3. Analysis
2.3.1. Without prior extraction of tin by the coprecipitation with ferric hydroxide
A portion of the sample weighing 1 g is placed in a beaker with a capacity of 250 cm, add 5 g of sodium chloride, 20 cm
of concentrated hydrochloric acid and heated. In the heating process is administered 7−10 cm
of hydrogen peroxide in small portions to dissolve the sample. After complete dissolution of the sample solution was evaporated to 3−4 cm
.
When the mass fraction of tin from 0.002 to 0.01%, all of the obtained solution transferred to a separatory funnel with a capacity of 150 cm. When the mass fraction of tin in excess of 0.01% solution was transferred to volumetric flask with a capacity of 250 cm
, was adjusted to the mark with water and mix. Aliquot part of the obtained solution volume of 25 cm
(with mass fraction of tin from 0.01 to 0.1%), 5 cm
(with mass fraction of tin from 0.1 to 0.4%) or 2,5 cm
(with mass fraction of tin from 0.4 to 0.7%) was placed in a separating funnel with a capacity of 150 cm
.
When determining the tin content of siliceous or lead alloys in the presence of sediment, aliquot part taken from a pre-filtered solution.
The solution in the separating funnel is neutralized dropwise with ammonia until slightly alkaline reaction on Congo paper and pour 5 cmof hydrochloric acid diluted 1:4. Then add 20 cm
of a solution of thiourea and then diluted with water to 70 cm
. When using the whole sample add 35−40 cm
of a solution of thiourea to obtain a colorless and transparent solution. Then injected 25 cm
of a solution of quercetin in n-butyl alcohol and vigorously shaken for 5 min. After phase separation, the lower layer discarded, avoiding the remainder of the aqueous phase, and the organic layer is poured into a dry beaker with a capacity of 50 cm
containing 0.2−0.5 g of anhydrous sodium sulfate, and after 5 min measure the optical density in a cuvette with a layer thickness of 1 cm on a photoelectrocolorimeter with a blue or violet filter at a wavelength of 420−450 nm or on a spectrophotometer at a wavelength of 440 nm. Solution comparison is the solution of quercetin in n-butyl alcohol.
2.3.2. Pre-allocation of tin by the coprecipitation with ferric hydroxide
A sample of alloy weighing 1 g is placed in a beaker with a capacity of 250 cm, and dissolved in 10 cm
of a mixture of acids. After dissolution of the alloy add 2cm
of a solution of ferric chloride and diluted with water to a volume of 150 cm
. Precipitated hydroxide with ammonia diluted 1:1 to the transition of copper into a soluble blue complex. The solution is heated and maintained at 60−70 °C for 20−30 min the Precipitate was filtered off on a medium density filter and washed with hot ammonia solution, diluted 1:50. The precipitate is dissolved in 20 cm
of hydrochloric acid diluted 1:1. The filter is washed with hot water. The solution was evaporated to 10−16 cm
and the mass fraction of tin from 0.002 to 0.01%, all of the obtained solution transferred to a separatory funnel with a capacity of 150 cm
, while the mass fraction of tin, 0.01% solution was transferred to volumetric flask with a capacity of 250 cm
, made up to the mark with water and mix. Further analysis are as indicated in claim
Since the bulk of the copper is separated, the interfering influence of the remaining quantities of copper and iron can be eliminated by addition of 15 cmof a solution of thiourea.
2.3.3. Construction of calibration curve
In a separating funnel with a capacity for 150 cm tomake 10 cm
of a standard solution of copper, consistently introduce 0; 1; 3; 5; 7 and 10 cm
standard solution B tin. The solutions were neutralized with ammonia to slightly alkaline environment at the paper of the Congo, poured 5cm
of hydrochloric acid, diluted 1:4, and further analysis are as indicated in claim
On the found values of optical densities build the calibration graph.
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;
— weight (or maintain it in aliquotes part),
2.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1.
Table 1
| Mass fraction of tin, % |
|
|
| From 0,0010 to 0.0025 incl. |
0,0002 |
0,0003 |
| SV. 0,0025 «0,0050 « |
About 0.0006 |
0,0008 |
| «0,005» 0,010 « |
0,002 |
0,003 |
| «Of 0.010» to 0.025 « |
0,003 |
0,004 |
| «0,025» 0,050 « |
0,005 |
0,007 |
| «0,05» 0,10 « |
0,008 |
0,01 |
| «To 0.10» to 0.25 « |
0,015 |
0,02 |
| «0,25» 0,50 « |
0,03 |
0,04 |
| «0,5» 1,0 « |
0,06 |
0,08 |
| «1,0» 2,0 « |
0,10 |
0,14 |
| «To 2.0» 5,0 « |
0,15 |
0,2 |
(Changed edition, Rev. N 2, 4).
2.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed the values specified in table.1.
(Changed edition, Rev. N 2, 4).
2.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315, or by additives, or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 4).
2.4.4.1−2.4.4.3. (Deleted, Rev. N 4).
3. POLAROGRAPHIC METHOD FOR THE DETERMINATION OF TIN
3.1. The essence of the method
The method is based on the separation of tin by the coprecipitation from a hydroxide of beryllium in ammonium solution containing Trilon B, with subsequent polarographic determination of tin in hydrochloric acid background. The half-wave potential (peak) recovery of tin of about minus 0.45 V relative to the saturated calomel electrode.
3.2. Apparatus, reagents and solutions
Polarograph AC-PPT-1 or oscilloscope FOR polarograph-5122, or other suitable polarograph AC complete with all accessories.
Polarographic cell, made of glass with a capacity of 40 cm, with a remote electrode (saturated calomel element) and mercury-drip cathode.
Nitrogen gas according to GOST 9293.
Hydrochloric acid according to GOST 3118, concentrated, dilute 1:1 and 1:3.
Nitric acid according to GOST 4461, diluted 1:1.
Beryllium nitrate, 10% aqueous solution.
Ammonia water according to GOST 3760, concentrated and the 2% solution.
Sulfuric acid according to GOST 4204.
Disodium salt of Ethylenediamine-,
,
,
-tetraoxane acid (Trilon B) according to GOST 10652, 0.1 mol/DM
solution; prepared as follows: 37,22 g Trilon B dissolved in 1 DM
of water.
Hydrogen peroxide according to GOST 10929.
Tin stamps O0 GOST 860.
Standard solutions of tin.
Solution A, prepared as follows: a portion of tin with a mass of 0.1 g was placed in a conical flask with a capacity of 250 cmand dissolved in 10−15 cm
of concentrated sulfuric acid. After the dissolution of tin and the solution was cooled poured 100 cm
of water and 50 cm
of concentrated hydrochloric acid, transfer the solution into a volumetric flask with a capacity of 1 DM
, made up to the mark with water and mix.
1 cmof solution A contains 0.1 mg of tin.
Solution B is prepared as follows: pipetted 10 cmof solution A in a volumetric flask with a capacity of 100 cm
, made up to the mark with hydrochloric acid diluted 1:3 and stirred.
1 cmof a solution contains 0.01 mg of tin.
Solution B is prepared before use.
(Changed edition, Rev. N 4).
3.3. Analysis
The weight of the alloy (tab.2) is placed in a beaker with a capacity of 250 cm, cover with a watch glass and dissolved in 20 cm
of nitric acid, diluted 1:1, and 5 cm
of concentrated hydrochloric acid with mild heating. After dissolution of the alloy solution was cooled, add 5 cm
of a solution of nitrate of beryllium, washed the glass and the side of the Cup with water, heated to 70−80 °C and to the hot solution add 20 cm
of a solution of Trilon B. the Solution is again heated to 80 °C, diluted with water to a total volume of 150 cm
and add concentrated ammonia solution until the formation of a soluble deep blue ammonia complex of copper and excess of that injected another 5 cm
of ammonia in excess. The solution is kept hot bath for 30−40 min, after which the hot solution is filtered through a dense filter of «blue ribbon» and washed precipitate on the filter 5−7 times with hot 2% solution of ammonia.
Table 2
| Mass fraction of tin, % |
The mass of charge, g |
Polarographically the volume of solution, cm |
| From 0.001 to 0.003 incl. |
1 |
40 |
| SV. Of 0.003 «to 0.01 « |
1 |
20 |
| «To 0.01» to 0.025 « |
1 |
10 |
| «Of 0.025» to 0.05 « |
0,5 |
5 |
| «0,05» 0,1 « |
0,5 |
2 |
| «0,1» 0,5 « |
0,1 |
5 |
The funnel with the precipitate was placed on glass, which conducted the deposition, and dissolve the residue in 20 cmhot hydrochloric acid, diluted 1:3, adding a few drops of hydrogen peroxide in the presence in the alloy of manganese.
The filter is washed with 20 cmof hot water, diluted the solution to 150 cm
of water, add 15 cm
of Trilon B solution and repeat the precipitation.
After three perioadele the filter cake is dissolved in 25 cmof hydrochloric acid diluted 1:3, and the solution transferred to a volumetric flask with a capacity of 50 cm
, made up solution to the mark with the same hydrochloric acid solution and stirred.
At the same time spend control experience.
Aliquot part of the obtained solution (see table.2) is transferred into a polarographic cell, previously washed with hydrochloric acid diluted 1:3. The solution in the cell is degassed flowing nitrogen for 5−7 minutes, then stop stirring and remove the cathodic polarization curve in the voltage range from minus 0.25 to minus 0.7 V. the Peak recovery of tin recorded in the field minus 0,45 V. the Sensitivity of the recording instrument is chosen so that the peak height of the tin was at least 15 mm.
The tin content find by the method of standard additions. Aliquot part of the solution A or B, depending on the tin content, is introduced into polarographically solution, pass nitrogen for 3 min and lead further analysis as in the determination of tin in the test solution. The value of the standard additives is chosen so that the peak height of the tin after the introduction of the additive increased 1.5−2 times. The volume of standard addition should not exceed 0.5 cm
.
3.4. Processing of the results
3.4.1. Mass fraction of tin () in percent is calculated by the formula
where is the height of the peak of tin in polarography solution in the reference experiment, mm.
— the height of the peak of tin in polarography of test solution, mm;
— the height of the peak of tin in polarography solution after the introduction of standard additives, mm;
— the volume of standard addition, mm;
— concentration of standard solution, g/cm
;
— the weight of the portion of the alloy taken on polarography, g
.
3.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1.
(Changed edition, Rev. N 2, 4).
3.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed the values specified in table.1.
(Changed edition, Rev. N 2, 4).
3.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315, or by additives, or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 4).
3.4.4.1−3.4.4.3. (Deleted, Rev. N 4).
4. TITRIMETRIC METHOD FOR DETERMINATION OF TIN
4.1. The essence of the method
The method is based on separation of tin from copper and zinc by coprecipitation with ferric hydroxide, a recovery of tetravalent tin to divalent metal lead or aluminum, or phosphonoacetate sodium, or calcium, and titration of divalent tin solution of iodine in presence of starch as indicator.
4.2. Apparatus, reagents and solutions
Feed hopper with hydraulic gate.
Tin with a mass fraction of tin of at least 99.95 percent or the standard sample tin N 99.
Solution tin standard; prepared as follows: 0.5 g of tin (or standard sample) dissolved in 20 cmof concentrated sulfuric acid, transferred to a volumetric flask with a capacity of 500 cm
and add to the mark with sulfuric acid diluted 1:5.
Aluminium GOST 11069, h, brand АВ0 (shavings or a thin plate).
Lead according to GOST 3778, h, grade C3 (plate length 8−10 cm, width 1.5−2.0 cm and weight 25−30 g).
Sodium posterolaterally according to GOST 200.
Calcium posterolaterally.
Nitric acid according to GOST 4461.
Hydrochloric acid according to GOST 3118 and diluted 1:1.
Sulfuric acid according to GOST 4204, and diluted 1:5.
A mixture of hydrochloric and nitric acids in the ratio 3:1, freshly prepared.
Ammonia water according to GOST 3760.
Ammonium chloride according to GOST 3773, solution 20 g/DM, which added 20 cm
of ammonia in 1 DM
solution.
Iron chloride according to GOST 4147, solution; is prepared as follows: 12 g of ferric chloride dissolved in 30 ml of concentrated hydrochloric acid and dilute with water to 1 DM.
Odnoklasnica mercury (calomel).
The acidic sodium carbonate according to GOST 4201 saturated without heating the solution.
Marble electrode according to GOST 4416.
Potassium iodide according to GOST 4232.
The soluble starch according to GOST 10163, a solution of 10 g/DM.
Iodine GOST 4159, 0.05 mol/DMsolution.
Carbon dioxide obtained in the apparatus of the Kippa.
Antimony chloride according to GOST 1089, a solution of 10 g/DM.
Determination of the mass concentration of iodine solution
50 cmof a standard solution of tin is transferred to a conical flask with a capacity of 500 cm,
add 20 cm
of a solution of ferric chloride, 80 cm
of concentrated hydrochloric acid, dilute with water to 250 cm
, add 2 g of aluminum, closing the flask funnel with stopper filled with a solution of acidic sodium carbonate, and further analysis are as indicated in claim
For the recovery of tetravalent tin used the same reducing agent as in the analysis of the samples (aluminum, lead or posterolaterally sodium or calcium), observing the same pH and temperature cooling.
The mass concentration of iodine solution (), expressed in grams of tin per 1 cm
of a solution, calculated by the formula
0,05 where — weight of tin, taken for titration, g; — the volume of iodine solution, spent on titration, sm
.
(Changed edition, Rev. N 4).
4.3. Analysis
4.3.1. Recovery of tetravalent tin to divalent aluminum
A portion of the alloy weight 2 g (for mass fraction of tin is from 0.7 to 2%) and a mass of 1 g (with mass fraction of tin from 2 to 5%) were placed in a glass with a capacity of 400 cm, cover with a watch glass and dissolved in 20 cm
of a mixture of acid with gentle heating. To the solution was added 20 cm
of a solution of ferric chloride, dilute with water to 250 cm
, heated to 70−80 °C and ammonia is added to the transition of divalent copper in a soluble blue ammonium complex. The solution was incubated at 70 °C to coagulate the precipitate for 10 min.
The precipitate was filtered off on a medium density filter and washed 6−7 times with a hot solution of ammonium chloride. The filter is removed, revealing, the precipitate washed with hot water in the same Cup, which was held a deposition, and dissolved in 20 cmof hot hydrochloric acid, diluted 1:1. The filter is then washed with hot water, and then 20 cm
of hot hydrochloric acid, diluted 1:1, and again with hot water.
Solution top up with water to 100 cm, add 50 cm
of concentrated hydrochloric acid and about 3 g of iron powder. Beaker cover watch glass, and the restoration carried out in a water bath for 30−45 minutes and consider it finished, if most of the iron present in solution until after filtration. The solution was filtered through a filter of average density in the conical flask with a capacity of 500−1000 cm
. The solution was thoroughly washed 4−5 times with hydrochloric acid, diluted 1:19 (about 150 cm
).
Reprecipitation of hydroxide repeated two more times. The washed precipitate of the solution on the filter 60 cmhot hydrochloric acid, diluted 1:1, introducing it in portions of 20 cm
. After each portion of hydrochloric acid, the filter washed with hot water. The filtrate is collected in the same glass.
The solution was transferred to a conical flask with a capacity of 500 cm, add 60 cm
of concentrated hydrochloric acid and dilute with water to 250 cm
. To the solution add 2 g of aluminum, the flask closed hopper with hydraulic gate, filled with a solution of acidic sodium carbonate. It is necessary to constantly monitor the completeness of filling of the funnel with a solution of acidic sodium carbonate in order to avoid infiltration of air into the flask. The contents of the flask are heated and boiled to completely dissolve aluminum, then the flask with the solution is removed from the heat, add 2−3 pieces of marble (about 5 g) or pass a current of carbon dioxide, obtained in the apparatus of the Kippa, then slightly cooled in air, then in running water to room temperature. Cooled the flask with the solution released from the funnel with the stopper in the flask add 2 g of potassium iodide, 5 cm of
starch solution and titrate with 0.05 mol/DM
iodine solution until a blue color.
(Changed edition, Rev. N 4).
4.3.2. Recovery of tetravalent tin to divalent lead
When you restore a tetravalent tin lead to hydrochloric acid solution of tin, located in the conical flask with a capacity of 500 cm, add 30 cm
of concentrated hydrochloric acid and dilute with water to 250 cm
. The flask down lead plate, close the flask in the usual funnel and heated to weak boiling, which is maintained for 60 min. the volume of solution in the flask to maintain a constant by adding hot water. Before the end of restoration closing the flask with a funnel with a stopper, filled with acidic carbonic sodium, and boil for another 10 mins Then do the same when restoring aluminum. Titrated without removing from a solution of lead acetate. The repeated use of lead plates with them it is necessary each time to remove the coating of oxides by mechanical means.
(Changed edition, Rev. N 4).
4.3.3. Recovery of tetravalent tin to divalent phosphonoacetate sodium or calcium
When you restore a tetravalent tin phosphonoacetate sodium or calcium to hydrochloric acid solution of tin in a flask with a capacity of 500 cm, add 10 cm
of concentrated hydrochloric acid and water to 250 cm
. To the solution was added 1.5 g phosphonoacetate sodium or calcium and 0.03 g of calomel. The conical flask was closed with stopper filled with acidic sodium carbonate, the solution was heated until complete discoloration and then another 5 min. After cooling the solution analysis continue when restoring aluminum.
4.4. Processing of the results
4.4.1. Mass fraction of tin () in percent is calculated by the formula
where is the volume of iodine solution consumed for titration, cm
;
— mass concentration of iodine solution, expressed in g/cm
tin;
— the weight of the portion of alloy,
(Changed edition, Rev. N 4).
4.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1.
4.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed the values specified in table.1.
(Changed edition, Rev. N 2, 4).
4.4.4. The control analysis is carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315, or by additives, or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 4).
4.4.4.1−4.4.4.2. (Deleted, Rev. N 4).
5. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF TIN WITH PHENYLFLUORONE
5.1. The essence of the method
The method is based on dissolving the sample in nitric or nitric and hydrofluoric acids, separation of tin on gidratirovannogo manganese dioxide from the environment 2 mol/DMnitric acid and photometric determination in the form of a complex with phenylfluorone in the presence of ascorbic and citric acids, masking iron (III) and antimony, and measuring the optical density of colored solution at 510 nm.
5.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461, diluted 1:1, 2 mol/DMsolution.
Hydrofluoric acid according to GOST 10484.
Sulfuric acid according to GOST 4204, and diluted 1:1, 1:4 and 2.5 mol/DMsolution.
Ascorbic acid, a solution of 20 g/DM, freshly prepared.
Citric acid according to GOST 3652, a solution of 200 g/DM, freshly prepared.
Ammonia water according to GOST 3760.
Manganese nitrate solution 50 g/DM.
Potassium permanganate according to GOST 20490, a solution of 10 g/DM.
Hydrogen peroxide according to GOST 10929, a solution of 30 g/DM.
Gelatin, a solution of 10 g/DMfreshly prepared.
Acetone according to GOST 2603.
Ethyl alcohol, rectified technical GOST 18300.
Phenylfluorene, a solution of 0.5 g/lin ethanol: 0.125 g of reagent was dissolved with heating in a glass with a capacity of 100 cm
in 50 cm
of ethyl alcohol with addition of 2 cm
of sulphuric acid diluted 1:1. The solution was cooled, poured into a volumetric flask with a capacity of 250 cm
, made up to the mark with ethanol and mix. The solution was stored in a dark place.
Tin metal according to GOST 860, grade O1.
Standard solutions of tin
Solution a: 0,1000 g of tin are dissolved in 10 cmof concentrated sulfuric acid, the solution was cooled, transferred to a measuring flask with volume capacity of 1000 cm
, made up to the mark of 2.5 mol/DM
sulfuric acid solution and stirred.
1 cmof solution A contains 0.1 mg of tin.
Solution B: 25 cmstandard solution And the tin is transferred to a volumetric flask with a capacity of 250 cm
, made up to the mark of 2.5 mol/DM
sulfuric acid and stirred.
1 cmof a solution contains 0.01 mg of tin.
5.1, 5.2. (Changed edition, Rev. N 4).
5.3. Analysis
5.3.1. For alloys containing silicon up to 0.05%
A portion of the alloy (tab.5) is placed in a beaker with a capacity of 250 cm, adding 10 cm
of nitric acid, diluted 1:1 and dissolved by heating.
Table 5
| Mass fraction of tin, % |
The weight of the portion of the sample, g | The volume of sample solution, cm |
The volume aliquote part of the solution, cm |
A volume of 2.5 M sulfuric acid, see |
| From 0.005 to 0.03 incl. |
2 |
100 |
10 |
0,5 |
| SV. 0,03 «0,06 « |
1 |
100 |
10 |
0,5 |
| «0,06» 0,12 « |
1 |
100 |
5 |
1,0 |
| «And 0.12» to 0.25 « |
0,5 |
200 |
10 |
0,5 |
| «0,25» 0,5 « |
0,5 |
200 |
5 |
1,5 |
| 70 |
The solution was boiled to remove oxides of nitrogen and top up with water to a volume of 50 cm. Add 5 cm
of a solution of nitrate of manganese. The solution is neutralized with ammonia until the appearance of the precipitate copper hydroxide, add 24 cm
of nitric acid, diluted 1:1, and water to a volume of 90 cm
. Heat almost to boiling, add 10 cm
of a solution of potassium permanganate, and boil for 2 min. after 30 min the precipitate was filtered off on a tight filter and wash the beaker and filter 8−10 times with hot 2 mol/DM
nitric acid until the disappearance of blue color of copper nitrate.
The deployed filter is washed with water in a glass, which conducted the deposition. The filter is washed with 10 cmof hot sulfuric acid, diluted 1:4 with a few drops of hydrogen peroxide and then water. The solution is evaporated until white smoke of sulfuric acid. To the cooled residue in the tin content of up to 0.12% add 20 cm
, while the mass fraction of tin in excess of 0.12% — 40 cm
2.5 mol/DM
sulfuric acid. The solution is poured according to the table in the appropriate volumetric flask, made up to the mark with water and mix.
In a volumetric flask with a capacity of 25 cmis placed aliquot part of the solution, add 2.5 mol/DM
sulfuric acid according to the table and poured alternately, stirring after each addition of reagent, 2 cm
of ascorbic acid solution, 5 cm
of the citric acid solution, 1 cm
of solution of gelatin, 3 cm
of acetone, 2 cm
of mortar perfluorane topped up to the mark with water and mix. After 3 h measure the optical density of the solution at 510 nm and 1 cm cuvette with a Solution of comparison is the solution of the reference experiment.
5.3.2. In alloys containing silicon in excess of 0.5%
A sample weighing 1 g is placed in a platinum Cup, add 10 cmof nitric acid, diluted 1:1 and 2 cm in
hydrofluoric acid and heated until dissolved. Then add 10 cm
sulphuric acid diluted 1:1, and is evaporated until the white fumes of sulfuric acid. The residue is cooled, the walls of the Cup should be rinsed with 5−7 cm
of water and again evaporated to fumes of sulfuric acid. The residue is cooled, the walls of the Cup should be rinsed with 20 cm
of water, heat the solution to dissolve the precipitate, poured into a glass with a capacity of 250 cm
, top up with water to 50 cm
, add 5 cm
of a solution of manganese nitrate, and then supplied as specified in clause
5.3.3. Construction of calibration curve
In seven of eight glasses with a capacity of 50 cmplaced 1,0; 2,0; 3,0; 4,0; 5,0; 6,0 and 7.0 cm
standard solution B, which corresponds to 0,01; 0,02; 0,03; 0,04; 0,05; 0,06 and 0.07 cm
tin, and then the solutions were evaporated to dryness and cooled. All glasses add 2.5 cm
to 2.5 mol/DM
sulphuric acid, heat the solution, add 2 cm
of ascorbic acid solution, cooled and fed as specified in clause
According to the obtained values of optical densities and corresponding contents of the tin to build the calibration graph.
(Changed edition, Rev. N 4).
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 volume of initial sample solution, cm
;
— volume aliquote parts of a solution of the sample, cm
;
— the weight of the portion,
5.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1.
5.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed the values specified in table.1.
5.4.2,
5.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA) or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315, or by additives, or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 4).
5.4.4.1−5.4.4.3. (Deleted, Rev. N 4).
6. ATOMIC ABSORPTION METHOD
6.1. The essence of the method
The method is based on dissolving the sample in a mixture of nitric and hydrochloric acids or, if the tin content in the alloy is less than 0.2% in the preliminary concentration of tin in gidratirovannogo coprecipitation on manganese dioxide and measuring the atomic absorption of tin in the flame acetylene-air, acetylene-nitrous oxide or hydrogen-air using radiation with a wavelength of 286,3 nm or 224,6.
6.2. Apparatus, reagents and solutions
The atomic absorption spectrometer.
Electrodeless lamp or hollow cathode for tin.
Hydrochloric acid according to GOST 3118 and diluted 2:1, 1:1 and 5:100.
Nitric acid according to GOST 4461 and diluted 1:1 and 1:100.
A mixture of acids: hydrochloric, diluted 1:1, and nitric, diluted 1:1, 1:1 ratio.
Ammonia water according to GOST 3760.
Potassium permanganate according to GOST 20490, a solution of 50 g/DM.
Manganese sulfate according to GOST 435, a solution of 80 g/DM.
Hydrogen peroxide according to GOST 10929.
Copper metal according to GOST 859, with a mass fraction of tin is less than 0.0005%.
The copper solution: 50 g of copper is dissolved in 350 cmof the mixture of acids, is transferred into a volumetric flask with a capacity of 500 cm
and topped to the mark with water.
10 cmof the solution contains 1 g of copper.
Zinc GOST 3640 with a mass fraction of tin is less than 0.0005%.
A solution of zinc: 50 g of zinc is dissolved in 250 cmof the mixture of acids, is transferred into a volumetric flask with a capacity of 500 cm
and topped to the mark with water.
10 cmof the solution contains 1 g of zinc.
Manganese GOST 6008 with a mass fraction of tin of 0.0005%.
The solution of manganese: 10 g of manganese dissolved in 40 cmof concentrated nitric acid, adding 250 cm.
of concentrated hydrochloric acid, transferred to a measuring flask with volume capacity of 1000 cm
and top up with water to the mark.
10 cmof a solution contain 0.1 g of manganese.
Tin stamps 01 according to GOST 860.
A standard solution of tin, 1 g of tin in the form of fine shavings are dissolved without heating in 100 cmof concentrated hydrochloric acid. Add another 50 cm
of concentrated hydrochloric acid and the solution transferred to a volumetric flask with a capacity of 1000 cm
, made up to the mark with hydrochloric acid diluted 5:100, and stirred.
1 cmof the solution contains 1 mg of tin.
6.3. Analysis
6.3.1. When the mass fraction of tin from 0.2 to 3% a portion of the alloy weight 2 g (with mass fraction of tin to 1%) or 0.5 g (at a mass fraction more than 1%) was dissolved in a beaker with a capacity of 250 cmat 20 or 10 cm
of the mixture of acids. After dissolution the solution was transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with water, mix and measure the atomic absorption of tin in the sample solution in parallel with the solutions to construct the calibration curve and the reference experiment in the flame acetylene-air or acetylene-nitrous oxide, using radiation with a wavelength of 286,3 nm.
(Changed edition, Rev. N 3).
6.3.2. When the mass fraction of tin from 0.005 to 0.2% of the weight of the alloy weight set depending on the mass fraction of tin at the table.6, is placed in a tall glass with a capacity of 600 cm, and dissolved in a mixture of acids in an amount as shown in table.6.
Table 6
| Mass fraction of tin, % |
The weight of the portion of the sample, g | The volume of the mixture of acids, see |
| From 0.005 to 0.04 incl. |
10, |
100 |
| SV. Of 0.04 «to 0.10 « | 4,0 |
40 |
| «To 0.10» to 0.20 « | 2,0 |
20 |
After dissolution, the sample solution is diluted with water up to 200−300 cm, neutralized with ammonia before the emergence of unfading during mixing of sediment, then add the required quantity of nitric acid diluted 1:1, prior to its dissolution (the pH of the solution should be 2−3). If the mass fraction of manganese in the alloy is less than 0.5%, the solution was added 2.5 cm
of a solution of sulphate of manganese, heated to boiling, add 3 cm
of a solution of potassium permanganate, and boil for 1 min. the Solution was allowed to stand for 30 minutes, after which the precipitate was filtered on a medium density filter and washed 5 times with nitric acid, diluted 1:100.
Wash the precipitate into the beaker in which precipitation was carried out, and the filter cake is dissolved in 15 cmof hydrochloric acid, diluted 2:1, and the solution transferred to a volumetric flask with a capacity of 25 cm
, top up to the mark with hydrochloric acid diluted 5:100, mix and measure the atomic absorption of tin as specified in claim
The measurement is carried out in a flame of hydrogen and air (especially at lower concentrations), acetylene-air or acetylene-nitrous oxide at a wavelength of 286,3 nm or 224,6.
6.3.3. Construction of calibration curve
6.3.3.1. When the mass fraction of tin from 0.2 to 3% in six of the seven volumetric flasks with a capacity of 100 cmmeasured 4,0; 6,0; 8,0; 10,0; 15,0 and 20.0 cm
standard solution of tin, which corresponds to 4,0; 6,0; 8,0; 10,0; 15,0 and 20,0 cm
tin.
All flasks is poured solutions of copper and zinc in accordance with their concentration in the analyzed sample solution, add 5 cmof the mixture of acids, made up of hydrochloric acid (5:100) to the mark and mix.
(Changed edition, Rev. N 3).
6.3.3.2. When the mass fraction of tin from 0.005 to 0.2% in five of the six tumblers with a capacity of 600 cmmeasure 0,5; 1,0; 2,0; 3,0 and 4,0 cm
standard solution of tin, which corresponds to 0,5; 1,0; 2,0; 3,0 and 4,0 mg of tin in each Cup of water added to a volume of 200 cm
and set pH 2−3 with a solution of nitric acid and then act as indicated in item
6.3.3.3. Measure the atomic absorption of tin just before and after the measurement of absorption of tin in the analyzed sample solution. According to the obtained values build the calibration graph.
6.4. Processing of the results
6.4.1. Mass fraction of tin () in percent is calculated by the formula
where is the concentration of tin in the analyzed solution samples, was found in the calibration schedule, g/cm
;
— the concentration of tin in solution in the reference experiment, was found in the calibration schedule, g/cm
;
— volume of the volumetric flask for solution preparation of sample, cm
;
— weight of charge, g
.
6.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1.
6.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed the values specified in table.1.
6.4.2,
6.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315, or by additives, or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 4).
6.4.4.1−6.4.4.3. (Deleted, Rev. N 4).
