GOST 15483.9-78
GOST 15483.9−78 Tin. Methods for determination of zinc (with Amendments No. 1, 2)
GOST 15483.9−78
Group B59
INTERSTATE STANDARD
TIN
Methods for determination of zinc
Tin. Methods for determination of zinc
AXTU 1709
Date of introduction 1980−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
B. C. Baev, T. P. Almanova, G. M. Vlasov, C. B. Meshkova, L. V. Mishchenko, L. D. Savilov, R. D. Kresnicka
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. REPLACE GOST 15483.9−70
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced | Item number |
| GOST 199−78 | 2.2; 4.2 |
| GOST 2062−77 | 2.2; 4.2 |
| GOST 3118−77 | 2.2; 3.2 |
| GOST 3640−94 | 2.2; 3.2; 4.2 |
| GOST 3760−79 | 2.2 |
| GOST 4109−79 | 2.2; 4.2 |
| GOST 4204−77 | 2.2; 3.2 |
| GOST 4220−75 | 2.2; 3.2 |
| GOST 6709−72 | Of 2.2; 3.2 |
| GOST 10929−76 | 2.2 |
| GOST 11125−84 | 3.2 |
| GOST 14261−77 | 2.2; 4.2 |
| GOST 15483.0−78 | 1.1 |
| GOST 15483.2−78 | 3.2; 3.3.2 |
| GOST 18270−72 | 2.2; 4.2 |
| GOST 20288−74 | 2.2; 4.2 |
| GOST 24147−80 | 4.2 |
5. Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)
6. REPRINT (may 1999) with Amendments No. 1, 2 approved in August 1984, June 1989 (IUS 12−84, 10−89)
This standard specifies the photometric (with a mass fraction of zinc from the 0.0003 to 0.002%), atomic absorption (at a mass fraction of zinc from 0.001 to 0.002%) methods for determination of zinc and a visual colorimetric method for the determination of zinc content (with zinc mass fraction of from 0.00001 to 0,00003%).
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis and security requirements — according to GOST 15483.0.
(Changed edition, Rev. N 1).
2. PHOTOMETRIC METHOD
2.1. The essence of the method
The method is based on fotomaterialy colored complex with dithizone in carbon tetrachloride. The sample is decomposed in a mixture of hydrochloric and bromatological acids and bromine. Tin was removed in the form of bromide.
2.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Separating funnel with a capacity of 50, 150 and 300−400 cm.
Volumetric flasks with a capacity of 100 and 25 cmwith ground stoppers.
Distilled water according to GOST 6709, double-distilled.
Hydrochloric acid of high purity according to GOST 14261 and diluted 1:1.
Bromatologia acid according to GOST 2062.
Bromine according to GOST 4109.
Mix to dissolve: 25 cmhydrochloric acid, 25 cm
bromatological acid and 15 cm
of bromine.
Ammonia water according to GOST 3760, diluted 1:200.
Hydrogen peroxide according to GOST 10929.
The acetic acid of high purity according to GOST 18270.
Sodium acetate according to GOST 199.
Acetate buffer solution pH 4,7:136 g sodium acetate dissolved in water, transferred to a volumetric flask with a capacity of 1 DM, pour 60 cm
of acetic acid, adjusted to the mark with water, mix. Solution clean ditizona, which 100 cm
of solution is shaken with a solution of dithizone with a mass fraction of 0.005% in carbon tetrachloride in portions of 2−3 cm
until until no longer changes the color of dithizone. Then the remaining drops of dithizone recovered carbon tetrachloride and the solution was filtered through a small ashless filter.
Chernovetskiy sodium (sodium thiosulfate), the solution with a mass fraction of 50%. Clean ditizona the same as the buffer solution.
Carbon tetrachloride according to GOST 20288.
Ditson (diphenylthiourea) for NTD, about a solution with a mass fraction of 0.05% (spare): 50 mg dithizone dissolved in 50 cmof carbon tetrachloride, the solution was transferred to a separatory funnel and shaken twice with 100 cm
of ammonia solution diluted 1:200. Ammonia solutions poured together, pour 100 cm
of carbon tetrachloride, are added dropwise hydrochloric acid diluted 1:1, to slightly acid reaction, and shake the solutions to the discoloration of the water layer. Solution dithizone in carbon tetrachloride is transferred to a clean funnel, washed twice by shaking with water, filtered through a dry filter into a dry flask of dark glass. Solution store in a cool place.
Dition: approx solution with a mass fraction of 0.005%; prepared on the day of use by dilution of a backup solution of carbon tetrachloride in 10 times.
Zinc GOST 3640.
Solutions of the zinc standard.
Solution a (spare): 0,1000 g of zinc metal are dissolved in 10 cmof hydrochloric acid diluted 1:1, transferred to a volumetric flask with a capacity of 1 DM
, adjusted to the mark with water and mix.
1 cmof the solution contains 1·10
g of zinc.
Solution B is prepared on the day of application: 10 cmalternate solution is transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water and mix.
1 cmof a solution contains 1·10
g of zinc.
Potassium dichromate according to GOST 4220.
Sulfuric acid according to GOST 4204.
A mixture of chrome: a solution with a mass fraction of 10% potassium dichromate in concentrated sulfuric acid.
Hydrochloric acid according to GOST 3118.
(Amended,
Izm. N 1, 2).
2.3. Analysis
2.3.1. The dishes needed for analysis, washed successively with a mixture of chromic, hydrochloric acid, water, and washed at least twice with distilled water.
2.3.2. The weight of tin weight 1,0000 g placed in a beaker with a capacity of 250−300 cm(or a porcelain Cup with a capacity of 100−150 cm
), poured 10 cm
of the mixture to dissolve, cover with a watch glass and leave you without heating until complete dissolution of the sample.
Then wash the watch glass 3 cmof hydrochloric acid and evaporated to dryness at a moderate heat. To the cooled residue poured 5cm
of the mixture and evaporated again to dryness. Treatment 5 cm
of the mixture is repeated until the complete removal of the tin. To the dry salts pour 5 cm
of hydrochloric acid, a few drops of hydrogen peroxide and evaporated to dryness. Treatment with hydrochloric acid and hydrogen peroxide again.
To the dry residue pour 4 cmof water, cover with a watch glass and heated to dissolve the salts. The solution was transferred to a separatory funnel with a capacity of 50 cm
, the glass is washed with 4 cm
of water in two installments. To the solution in separating funnel pour 4 cm
of acetate buffer solution, 1 cm
chernovetskogo sodium, add 5 cm
of a solution of dithizone with a mass fraction of 0.005% and shaken for 1 min. After separation of the layers the organic layer decanted into a dry volumetric flask with a glass stopper with a capacity of 25 cm
. Extraction with 5 cm
of dithizone repeated until, until a new portion of dithizone will not change its color. The combined extracts was adjusted to the mark with ditizona, mix and filter the solution through a dry ash-free filter into a dry flask, discarding first portion of filtrate.
Optical density of the solution measured on a spectrophotometer at a wavelength of 540 nm or photoelectrocolorimeter using the filter with a light transmission region of 530−550 nm and cuvettes with an optimum thickness of the layer. As a solution comparison using the solution of dithizone with a mass fraction of 0.005%.
From the readings of the optical density of the analyzed solution subtract the readings of the optical density of control experiment through all stages of the analysis.
(Changed edition, Rev.
N 1, 2).
2.3.3. Construction of calibration curve. In a separating funnel with a capacity of 50 cm,measure with a pipette or microburette 0,0; 0,5; 1,0; 1,5; 2,0; 2,5 and 3.0 cm
standard solution, add water to 8 cm
, with stirring, for 4 cm
of acetate buffer solution, 1 cm
of solution servational sodium, 5 cm
dithizone solution with a mass fraction of 0.005% and then carry out the analysis, as mentioned in paragraph
From the optical density of the calibration solutions subtract the optical density of the zero solution and according to the obtained results build a calibration curve.
(Changed edition, Rev. N 2).
2.4. Processing of the results
2.4.1. Mass fraction of zinc () in percent is calculated by the formula
where is the mass of zinc that was found in the calibration schedule g;
— weight of tin,
2.4.2. Allowable absolute discrepancies in the results of parallel measurements at a confidence probability of 0.95 should not exceed the values given in table.1.
Table 1
| Mass fraction of zinc, % |
The absolute allowable difference, % |
| To 0,0003 |
0,00015 |
| SV. The 0.0003 «to 0.0005 |
0,0002 |
| «Of 0.0005» to 0.001 |
0,0004 |
| «Of 0.001» to 0.002 |
0,0005 |
3. ATOMIC ABSORPTION METHOD
3.1. The essence of the method
The method is based on selective absorption of light from a standard source of zinc atoms. The solution is sprayed in an acetylene-air flame atomic absorption spectrometer and measure the absorbance at a wavelength of 213,8 nm.
3.2. Equipment, reagents, solutions
Spectrometer of atomic absorption.
The glasses are made of PTFE with a capacity of 50 cm.
Nitric acid of high purity according to GOST 11125 and diluted 1:1.
Hydrofluoric acid of high purity.
Distilled water according to GOST 6709, double-distilled.
Mix to dissolve; cook according to GOST 15483.2.
A mixture of chromium; solution with a mass fraction of 10% potassium dichromate in concentrated sulfuric acid.
Zinc GOST 3640.
Solutions of the zinc standard.
Solution a: 0,1000 g of zinc is dissolved in 20 cmof nitric acid, diluted 1:1, transferred into a measuring flask with volume capacity of 1000 cm
, adjusted to the mark with water and mix.
1 cmof solution A contains 0.1 mg of zinc.
Solution B is prepared prior to use: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water and mix.
1 cmof a solution contains 0.01 mg of zinc.
Hydrochloric acid according to GOST 3118.
Potassium dichromate according to GOST 4220.
Sulfuric acid according to GOST 4204.
(Changed edition, Rev. N 1, 2)
.
3.3. Analysis
3.3.1. The dishes needed for the analysis, subjected to preliminary processing as described in claim
3.3.2. A portion of the sample weight 1,0000 g placed in the beaker made of PTFE with a capacity of 50 cmand poured in small portions to 10 cm
of the mixture for dissolution. Continue the analysis according to GOST 15483.2.
Fotometrirovanie is carried out at a wavelength of 213,8 nm under the conditions specified in GOST 15483.2.
The zinc concentration set at the calibration schedule, fotometriya simultaneously with the analyzed solutions a series of solutions with known content of zinc.
3.3.3. To build a calibration curve in a volumetric flask with a capacity of 50 cmmeasured 0; 1,0; 1,5; 2,0; 2,5 and 3,0 cm
standard solution B, and poured 10 cm
of the mixture for dissolution, adjusted to the mark with water and mix.
Photometric as specified in claim
(Changed edition, Rev. N 2).
3.4. Processing of the results
3.4.1. Mass fraction of zinc () in percent is calculated by the formula
where is the concentration fotometricheskogo solution, g/cm
;
— volume fotometricheskogo solution, cm
;
— weight of tin,
(Changed edition, Rev. N 1).
3.4.2. The absolute discrepancies in the results of parallel measurements at a confidence probability of 0.95 does not exceed 0,0005%.
4. VISUAL COLORIMETRIC METHOD
4.1. The essence of the method
The method is based on the formation of complex compounds of zinc with dithizone (dithizone zinc), the color intensity of which is determined visually by way of «mixed color». Tin is removed by a pre-Stripping in the form of bromide.
4.2. Apparatus, reagents and solutions
Separating funnel with a capacity of 50, 150 and 300−400 cm.
Volumetric flasks with a capacity of 100 cmwith pritertymi glass stoppers.
The cylinders are graduated to colorimetrically pritertymi with glass stoppers.
Quartz distillation apparatus.
Hydrochloric acid of high purity according to GOST 14261, purified from traces of heavy metals by distillation in a quartz apparatus, and a solution of 6 mol/DM.
Bromatologia acid according to GOST 2062, purified from traces of heavy metals by distillation in a quartz apparatus.
Bromine according to GOST 4109, purified by distillation in a quartz distillation apparatus.
The mixture of acids to dissolve: 25 cmhydrochloric acid, 25 cm
bromatological acid and 15 cm
of bromine.
The acetic acid of high purity according to GOST 18270, solution 2 mol/DM. Carbon tetrachloride according to GOST 20288, purified by distillation in a quartz distillation apparatus.
Decison for NTD, about a solution with a mass fraction of 0.02%: 20 mg dithizone dissolved in 50 cmof carbon tetrachloride, transfer the solution into a separating funnel with a capacity of 300−400 cm
, flow 50 cm
of ammonia, diluted 1:200, and vigorously stirred. Dithizone extraction is repeated with 50 and 25 cm
of ammonia. All of the ammonia extracts fused together, pour 100 cm
of carbon tetrachloride and shake the funnel, add dropwise a 6 mol/DM
hydrochloric acid until discoloration of the water layer. Solution dithizone in carbon tetrachloride is transferred to a clean funnel, washed twice by shaking with water and filtered through a dry filter into a dry flask of dark glass. Solution store in a cool dark place.
Ditson, about a solution with a mass fraction of 0.002 to them* 0,001%; prepared from a strong solution of dithizone, diluting it with carbon tetrachloride in a ratio of 1:10, 1:20 on the day of application.
_________________
* The text matches the original. — Note the manufacturer’s database.
Sodium acetate according to GOST 199, a solution of 2 mol/DM, cook and clean with dithizone: a sample of salt with a mass of 27.2 g dissolved in a glass in a little water, transferred into a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water and mix. The entire solution was transferred to a separatory funnel and extracted several times with 5.0 cm
of a solution of dithizone with a mass fraction of 0.002%. Clean finish, when a portion of dithizone after the shaking remains green. The remaining drops of dithizone is extracted by shaking several times with 5 cm.
of carbon tetrachloride. Flush finish where a touch of carbon tetrachloride after the shaking remains colorless.
The solution was filtered through a small ashless filter to remove droplets of carbon tetrachloride.
Acetate buffer solution with a pH of 4.7: mix equal volumes of 2 mol/DMsolution of sodium acetate and 2 mol/DM
acetic acid. Buffer solution clean ditizona as well as purified acetic acid and sodium.
Hydrogen peroxide OS.h. 15−3.
Chernovetskiy sodium (sodium thiosulfate), the solution with a mass fraction of 50% clean ditizona as well as purified acetic acid and sodium.
Zinc metal according to GOST 3640.
Solutions of the zinc standard.
Solution a (spare): 0.1 g of zinc metal are dissolved in 10 cmof hydrochloric acid diluted 1:1, transferred to a volumetric flask with a capacity of 1 DM
, adjusted to the mark with water and mix.
1 cmof the solution contains 1·10
g of zinc.
Solution B: 10.0 cmsolution And transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water and mix.
1 cmof a solution contains 1·10
zinc.
Solution: 10,0 cmof solution B is transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water and mix.
1 cmof the solution contains 1·10
g of zinc.
Solutions B and C prepared on the day of application.
The demineralized or bidistilled water according to GOST 6709, double-distilled in quartz apparatus.
The aqueous ammonia of high purity according to GOST 24147, diluted 1:200.
(Changed
I edition, Rev. N 1, 2).
4.3. Analysis
4.3.1. The weight of tin weight 1,0000 g is placed in a low-quartz glass with a capacity of 50 cm, covered with a watch glass, and dissolve in 7−10 cm
of the mixture of acids to dissolve.
The contents of the glass left without heating to dissolve the sample. After dissolution of tin, the glass is washed with 3 cmof hydrochloric acid and evaporated the solution is moderately heated on a tile to obtain a wet residue (2−3 drops). Treatment 5 cm
of the mixture of acids to dissolve is repeated until the complete removal of the tin, evaporating the solution to dryness. The dry residue is dissolved in 5 cm
of hydrochloric acid and evaporated to dryness.
If after treatment of dry residue with hydrochloric acid solution has a brown color, then to the resulting solution was added 3 cmof hydrochloric acid, a few drops of hydrogen peroxide and evaporated to dryness. If necessary this process is repeated again.
A chilled glass of dry residue is washed with 5 cmof water. The solution was gently evaporated to obtain dry residue. The glass is cooled to 50−60 °C and pour 2 cm
of water, then cover the watch glass, contents heated for 2−3 min at 50−60 °C and then translate the solution into the cylinder to colorimetrically.
Then the glass is washed with 2 cmof water in two steps and added to the subject solution. The cylinder pour 2 cm
of buffer solution, 0.5 cm
chernovetskogo sodium and stirred. Then add 2cm
of a solution of dithizone with a mass fraction of 0.001%, vigorously shake the cylinder for 1 min and compare the colour of the subjects of the extracts and calibration solutions in the reflected light on a white background, watching from a distance.
Through all stages of the analysis in parallel with the sample hold control experiments and corrected for contamination of the reagents by processing the results of an
Aliza.
4.3.2. For the preparation of the scale calibration mixtures in cylinders for colorimetrically measure 0,1; 0,2; 0,3; 0,4; 0,5 cmstandard solution, pour water to a volume of 4 cm
, 2 cm
buffer solution, 0.5 cm
chernovetskogo sodium and stirred, and then poured 2cm
of a solution of dithizone with a mass fraction of 0.001% and vigorously shaken for 1 min. the Solutions apply to colorimetrically for 1 h.
4.3.1,
4.4. Processing of the results
4.4.1. Mass fraction of zinc () in percent is calculated by the formula
where is the mass of zinc was found when compared with the calibration solutions, g;
— the mass of zinc in solution in the reference experiment, was found when compared with the calibration solutions, g;
— weight of tin,
4.4.2. Allowable absolute discrepancies in the results of parallel measurements at a confidence probability of 0.95 should not exceed the values given in table.2.
Table 2
| Mass fraction of zinc, % | The absolute allowable difference, % |
| From 0,00001 0,00003 up to | 0,00001 |
4.4.1,
