GOST 19251.6-79
GOST 19251.6−79 Zinc. Methods for determination of antimony (with Amendments No. 1, 2, 3)
GOST 19251.6−79
Group B59
STATE STANDARD OF THE USSR
ZINC
Methods for determination of antimony
Zinc. Methods of antimony determination
AXTU 1709
Date of introduction 1980−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
V. I. Lysenko, L. I. Maksay, R. D. Cohen, V. A. Kolesnikov, N. Romanenko, R. A. Pestova
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. Change No. 3 adopted by the Interstate Council for standardization, Metrology and certification (Protocol № 7 from 26.04.95)
The adoption voted:
| The name of the state | The name of the national authority standardization |
| The Republic Of Azerbaijan | Azgosstandart |
| The Republic Of Armenia | Armastajad |
| The Republic Of Belarus | Gosstandart Of Belarus |
| The Republic Of Kazakhstan | Gosstandart Of The Republic Of Kazakhstan |
| The Republic Of Kyrgyzstan | Kyrgyzstandart |
| The Republic Of Moldova | Moldovastandart |
| Russian Federation | Gosstandart Of Russia |
| The Republic Of Tajikistan | Tajikistandart |
| The Republic Of Turkmenistan | The main state inspection of Turkmenistan |
| The Republic Of Uzbekistan | Standards |
| Ukraine | Gosstandart Of Ukraine |
4. INSTEAD 19251.6 GOST-73
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Item number |
| GOST 195−77 |
3.1 |
| GOST 1089−82 |
2.2, 3.1, 4.2 |
| GOST 3118−77 |
2.2, 3.1, 4.2 |
| GOST 3760−79 |
2.2, 4.2 |
| GOST 4204−77 |
2.2, 3.1, 4.2 |
| GOST 4233−77 |
4.2 |
| GOST 4461−77 |
2.2, 3.1, 4.2 |
| GOST 5456−79 |
2.2 |
| GOST 10929−76 |
2.2 |
| GOST 19251.0−79 |
1.1 |
| GOST 20490−75 |
2.2, 4.2 |
| GOST 22159−76 |
4.2 |
6. Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)
7. REPRINT (January 1998) with Amendments No. 1, 2, 3, approved in October 1984, April 1989, June 1996 (ICS 1−85, 7−89, 9−96)
This standard specifies the photometric and polarographic methods for the determination of antimony in its mass fraction of from 0.0005 to 0.025%.
(Changed edition, Rev. N 3).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis and security requirements — according to GOST 19251.0.
(Changed edition, Rev. N 1).
2. PHOTOMETRIC METHOD WITH CRYSTAL VIOLET
2.1. The essence of the method
The method is based on dissolving the sample in nitric acid, the separation of antimony from other elements in the manganese dioxide and its photometric determination with crystal violet after extraction with trichloroethylene at a wavelength of 595 nm.
The sensitivity of the method is 5 micrograms of antimony in the amount of 25 cm.
(Changed edition, Rev. N 3).
2.2. Apparatus, reagents and solutions
Spectrophotometer or photoelectrocolorimeter of any kind for measurements in the visible region of the spectrum.
Nitric acid according to GOST 4461 diluted 1:2, 1:200 and a solution of 5 mol/DM.
Hydrochloric acid according to GOST 3118 and diluted 7:3 and 1:3.
Sulfuric acid according to GOST 4204, diluted 1:4, and the solutions are 2.5 and 0.25 mol/DM.
Ammonia water according to GOST 3760.
Hydrogen peroxide according to GOST 10929.
Potassium permanganate according to GOST 20490, a solution of 10 g/DM.
Manganese nitrate, solution 20 g/DM.
Cerium (IV) sulfate solution 4 g/lsolution sulfuric acid 0.25 mol/DM
.
Hydroxylamine dihydrochloride according to GOST 5456, a solution of 10 g/DM.
Crystal violet solution 2 g/DM.
The trichloroethylene.
Antimony brand Su00 according to GOST 1089.
Standard solutions of antimony.
Solution a: a suspension of finely divided antimony mass 0,1000 g is placed in a conical flask with a capacity of 500 cm, 150 cm poured
sulfuric acid, heated to complete dissolution of the sample, cooled, carefully poured 200 cm
of a hydrochloric acid solution 1:3, cooled, quantitatively 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 g of antimony.
Solution B: in a volumetric flask with a capacity of 100 cmwith a pipette measure out 10 cm
of solution A, made up to the mark with sulfuric acid solution 2.5 mol/l
and stirred.
1 cmof a solution contains 0.01 mg of antimony.
(Redrafted From
m. N 2, 3).
2.3. Analysis
2.3.1. Suspension zinc weight 0,5000 g is placed in a conical flask with a capacity of 250 cm, flow 15 cm
of nitric acid, diluted 1:2, and dissolved under heating. After removal of the oxides of nitrogen, the solution was diluted to 50 cm
with water, neutralized with ammonia before formation of the disappearing under stirring the precipitate, add 20 cm
of a solution of nitric acid 5 mol/DM
, top up with water to 100 cm
. Add 5 cm
of a solution of nitrate of manganese, heated to boiling, pour 5 cm
of a solution of potassium permanganate, and boil for 2−3 min. after 30 min the precipitate was filtered off on a medium density filter and washed 4−5 times with hot solution of nitric acid 1:200. The deployed filter is washed with water in the same flask in which precipitation was carried out.
The filter is washed with 10 cmof hot sulfuric acid, diluted 1:4, which added 5−6 drops of hydrogen peroxide and then several times with hot water. The resulting solution is poured into a glass with a capacity of 100 cm
, was evaporated until the appearance of sulphuric acid fumes, cooled, rinse the walls of the glass 3−4 cm
of water and evaporated to a moist residue.
To the cooled residue add appropriate amount of hydrochloric acid (table.1) and leave to dissolve the residue. When the mass fraction of antimony to 0.005% pour the solution into the separatory funnel with a capacity of 150 cm, add 3 cm
of water and at a higher antimony content of the solution was transferred to a volumetric flask with a capacity of 25 cm
, top up to the mark with water, mix and take 5 or 10 cm
of the solution in the separatory funnel with a capacity of 150 cm
. When aliquotes pieces of 5 cm
in the separatory funnel add 5 cm
of hydrochloric acid of 7:3.
Table 1
| Mass fraction of SB, % |
The volume of hydrochloric acid, see |
The volume of solution after dilution, see |
The solution volume selected for analysis, see |
| From 0.0005 to 0.005 |
7 | 10 | All |
| SV. 0,005 «0,01 |
17,5 | 25 | 10 |
| «0,01» 0,025 |
17,5 | 25 | 5 |
To the whole solution or its aliquote parts placed in separating funnel, add 0.5 cmof the solution of cerium sulfate, stirring after 1 min. pour 1 cm
of a solution of hydroxylamine dihydrochloride and mix again. After 1 min pour 19 cm
water, 10 cm
of trichloroethylene, 1 cm
of a solution of crystal violet and extracted for 1 min. After phase separation, the organic layer was transferred to a dry volumetric flask with a capacity of 25 cm
, and the aqueous layer again extracted with 10 cm
of trichloroethylene. The combined organic phase was diluted in volumetric flask to the mark with trichloroethylene and stirred.
The optical density of colored solution is measured in the relevant cuvette at a wavelength of 595 nm. Solution comparison is the solution of the reference experiment.
The antimony content is set according to the calibration schedule.
(Changed edition, Rev. N 2, 3)
.
2.3.2. To build a calibration curve in five of the six separatory funnels with a capacity of 150 cm, respectively, measure off microburette 0,5; 1,0; 1,5; 2,0 and 2,5 cm
standard solution B (equivalent to 5, 10, 15, 20 and 25 micrograms of antimony), poured into each of the separatory funnels 7.5 cm
of hydrochloric acid and, if necessary, top up with water to a volume of 10 cm
. Pour 0.5 cm
of the solution of cerium sulfate, and then do as described in claim
According to the obtained values of optical density of the solutions and the corresponding content of antimony building a calibration curve.
2.4. Processing of the results
2.4.1. Mass fraction of antimony (), %, is calculated by the formula
where is the mass of antimony in the solution was found in the calibration schedule, mcg;
— the weight of the portion contained in the selected part of the solution,
2.4.2. The absolute values of the differences between the results of two parallel measurements (rate of convergence) and the results of the two tests (index of reproducibility) with the confidence coefficient =0.95 does not exceed values of allowable differences specified in table.2.
Table 2
| Mass fraction of SB, % |
The permissible difference for parallel definitions % |
The permissible discrepancy between the results of the analysis % |
| From 0.0005 to 0,0030 incl. |
0,0003 | 0,0004 |
| SV. 0,0030 «0,010 « |
0,0010 | 0,0015 |
| «Of 0.010» to 0.025 |
0,003 | 0,004 |
(Changed edition, Rev. N 2).
3. PHOTOMETRIC METHOD WITH RHODAMINE B
The method is based on extraction of ions of antimony (V) Diisopropylamine ether from hydrochloric acid sample solution, elution of interfering ions of thallium (III) solution semitecolo of sodium, the formation of colored complex of rhodamine B with hexachloroantimonate (V) and measuring its light absorption at a wavelength of 550 nm.
3.1. Apparatus, reagents and solutions
Spectrophotometer or photoelectrocolorimeter of any kind for measurements in the visible region of the spectrum.
Nitric acid according to GOST 4461, diluted 1:1.
Hydrochloric acid according to GOST 3118 and solutions 12 and 1 mol/DM.
Sulfuric acid according to GOST 4204, diluted 1:1 and a solution of 0.25 mol/DM.
Sodium sanitarily according to GOST 195, a solution of 0.5 g/DM.
Live diisopropylamide.
Rhodamine B, a solution of 1 g/DM: 0.5 g of 3,6-bis-diethylamino-fluoran (rhodamine B) was placed in a volumetric flask with a capacity of 500 cm
, is dissolved in a solution of hydrochloric acid 1 mol/DM
, adjusted to the mark with hydrochloric acid 1 mol/l
and stirred.
Cerium (IV) sulfate solution 4 g/lsolution sulfuric acid 0.25 mol/DM
: 8.3 g of cerium sulfate (IV) poured 8 cm
of sulfuric acid and heated to release vapors of sulfuric acid. Cool. Carefully dilute with water to 100 cm
and again cooled. Sulphate solution is transferred to volumetric flask with a capacity of 250 cm
, was adjusted to the mark with water and mix.
Antimony brand Su00 according to GOST 1089.
Standard solutions of antimony.
Solution a: melkorublenoy 0,1000 g of antimony is placed in a beaker with a capacity of 250 cm, dissolved in 20 cm
of sulphuric acid at boiling temperature, cooled and diluted with sulfuric acid of 1:1 to 50 cm
. Transfer the solution into a measuring flask with a capacity of 1 DM
, adjusted to the mark with sulfuric acid solution 1:1, mix.
1 cmof solution A contains 0.1 mg of antimony.
Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with sulfuric acid solution 1:1 and stirred.
1 cmof a solution contains 0.01 mg of antimony.
Solution: 10 cmof a solution transferred to a volumetric flask with a capacity of 100 cm
, adjusted to the mark with sulfuric acid solution 1:1 and stirred.
1 cmof the solution contains 0.001 mg of antimony.
(Modified redakts
ia, Rev. N 1, 3).
3.2. Analysis
3.2.1. The weight of the portion selected depending on the mass fraction of antimony (tab.3), placed in a beaker with a capacity of 250 ml and dissolved in specified quantity of nitric acid solution.
Table 3
| Mass fraction of SB, % |
The mass of charge, g | The volume of nitric acid, see |
The volume aliquote part of the solution, cm |
| From 0.0005 to 0.001 | 2,5000 |
15 | 20 |
| SV. Of 0.001 «to 0.003 to | 1,0000 |
10 | 20 |
| «Of 0.003» to 0.01 | 0,5000 |
5 | 10 |
| «0,01» 0,025 | 0,5000 |
5 | 5 |
The solution is evaporated to dryness. After cooling, add 5 cmof sulphuric acid and again evaporated until the appearance of sulphuric acid fumes. The residue is dissolved in 10 cm
of hydrochloric acid. The solution was cooled, transferred to a volumetric flask with a capacity of 50 cm
, adjusted to the mark with hydrochloric acid and stirred.
Select aliquot part of the solution (table.3) in a separating funnel with a capacity of 150 cmand, if necessary, the volume was adjusted to 20 cm
by applying a solution of hydrochloric acid of 12 mol/DM
. To the solution was added 2 cm
of sulfate solution of cerium (IV) and 10 cm
diisopropylamido of ether and shaken for 30 s. After extraction, add 20 cm
of water and again shaken. After settling, the aqueous phase is drained and discarded. The organic phase is washed with a mixture of 5 cm
of hydrochloric acid of 1 mol/DM
and 2 cm
of a solution of sodium semitecolo.
The obtained aqueous phase is drained and discarded. The organic phase was again washed with 5 cmof hydrochloric acid of 12 mol/DM
and 1 cm
of sulfate solution of cerium (IV). Wash solution is discarded. To the organic phase add 2 cm
of a solution of rhodamine B and perform the extraction for 15 s. the Aqueous phase is discarded. Converting a portion of organic phase in the cuvette and measure the absorption of colored complex of antimony with rhodamine B at a wavelength of 550 nm. As a solution comparison at the same time apply the prepared solution in the reference experiment.
The antimony content is set according to the calibration schedule.
(Amended,
Izm. N 2).
3.2.2. To build a calibration curve in 10 of the 11 cups with a capacity of 250 cmmeasured with a burette 2,0; 5,0; 7,5 and 12,5 cm
standard solution b and 1,5; 2,0; 2,5; 3,0; 3,5 and 4,0 cm
standard solution B, that corresponds to the content 2,0; 5,0; 7,5; 12,5; 15,0; 20,0; 25,0; 30,0; 35,0 and 40.0 µg of antimony. The solutions were evaporated to remove sulfuric acid. After cooling, all the glasses are poured 10 cm
of hydrochloric acid, dissolve the salt and transfer the solutions into volumetric flasks with a capacity of 50 cm
. Solutions was adjusted to the mark with hydrochloric acid and stirred. Taken at 20 cm
from each solution and then act as described in section
According to the obtained values of optical density of the solutions and the corresponding content of antimony building a calibration curve.
Processing of results is carried out according to claim 2.4.
4. POLAROGRAPHIC METHOD
4.1. The essence of the method
The method is based on dissolving the sample in nitric acid, deposition of antimony on manganese dioxide from nitric acid 1 mol/DMand polarography of antimony in acidic netrevolution background electrolyte at a potential of minus 0.18 V relative to the saturated calomel electrode.
The sensitivity of the method of determination of antimony on the oscilloscope polarography 0.1 mg/DM, alternating current — 0,05 mg/DM
.
(Changed edition, Rev. N 3).
4.2. Apparatus, reagents and solutions
Polarography oscillographic or polarograph AC.
Nitric acid according to GOST 4461 diluted 1:2 and a solution of 5 mol/DM.
Hydrochloric acid according to GOST 3118.
Sulfuric acid according to GOST 4204, and diluted 1:5.
Ammonia water according to GOST 3760.
Manganese (II) nitrate.
Potassium permanganate according to GOST 20490, a solution of 10 g/DM.
Hydrazine dihydrochloride according to GOST 22159.
Sodium chloride according to GOST 4233.
Antimony brand Su00 according to GOST 1089.
Standard solution of antimony: a portion of finely powdered antimony with a mass 0,1000 g is placed in a conical flask with a capacity of 250 cm, flow 20 cm
of sulphuric acid, heated to dissolve, cooled, poured into a volumetric flask with a capacity of 1 DM
, made up to the mark with sulfuric acid diluted 1:5, and stirred.
1 cmof the solution contains 0.1 mg of antimony.
Calibration solutions of antimony in seven volumetric flasks with a capacity of 100 cmmeasured respectively 0,2; 0,5; 1,0; 1,5; 2,0; 2,5 3.0 cm and
a standard solution of antimony, made up to the mark and the background electrolyte and stirred. Solutions contain respectively 0,2; 0,5; 1,0; 1,5; 2,0; 2,5 and 3.0 mg/l
of antimony.
Background electrolyte: in a vessel with a capacity of 2 DMare placed 200 g of sodium chloride, 40 g of hydrazine dihydrochloride, 500 cm
of hydrochloric acid, poured water to a volume of 2 DM
and mixed.
(Changed edition, Rev. N
2, 3).
4.3. Analysis
The weight of zinc weight of 2,5000 g (with mass fraction of antimony 0.002%), 1,0000 g (with mass fraction of antimony from 0.002 to 0.005%) and 0,5000 g (with mass fraction of antimony 0.005%) was placed in a conical flask with a capacity of 250 cm, flow in line with its linkage 40, 20 or 15 cm
of nitric acid 1:2, heated to dissolve the sample and remove the nitrogen oxides. Diluted to 50 cm
with water, neutralized with ammonia before formation of the disappearing under stirring the precipitate, add 20 cm
of a solution of nitric acid 5 mol/DM
and top up with water to 100 cm
(the label on the bulb). Add 5 cm
of a solution of nitrate of manganese, heated to boiling, poured 5cm
of potassium permanganate solution, boil for 2−3 minutes and leave on the warm stove for 30 minutes to coagulate the precipitate.
The precipitate was filtered off on a paper filter of medium density. The filter cake and flask are washed 5−6 times with hot water. The deployed filter wash 30−35 cmhot background electrolyte in a flask in which to carry out the precipitation, cover the flask with a watch glass, boil for 2 min, cooled, transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark and the background electrolyte and stirred.
Part of the solution was placed in a polarographic cell and conduct polarography of antimony with a corresponding current range and the half-wave potential of minus 0.18 V relative to the saturated calomel electrode.
(Changed edition, Rev. N 2,
3).
4.4. Processing of the results
4.4.1. Mass fraction of antimony (), %, is calculated by the formula
where the wave height of antimony in solution, mm;
— volume of the volumetric flask, cm
;
— the concentration of antimony in calibration solution, mg/DM
;
wave height of antimony in the calibration solution, mm;
— weight of charge, g
.
4.4.2. The absolute values of the differences between the results of two parallel measurements (rate of convergence) and the results of the two tests (index of reproducibility) with the confidence coefficient =0.95 does not exceed values of allowable differences specified in table.2.
(Changed edition, Rev. N 2).
