GOST 15483.4-78

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  ГОСТ 15483.4-78

GOST 15483.4−78 (ST SEV 4809−84) Tin. Methods for determination of copper (with Amendments No. 1, 2, 3)

GOST 15483.4−78
(ST CMEA 4809−84)

Group B59

INTERSTATE STANDARD

TIN

Methods for determination of copper

Tin. Methods for determination of copper

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, V. 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 13.12.78 N 3300

3. The standard fully complies ST SEV 4809−84

4. REPLACE GOST 15483.4−70

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)

7. REVISED (April 1999) with Amendments No. 1, 2, 3, approved in August 1984, October 1985, June 1989 (IUS 12−84, 1−86, 10−89)


This standard specifies the photometric (with mass fraction of copper from 0.002 to 0.12%) and atomic absorption (at a mass fraction of copper from 0.005 to 0.12%) methods for determination of copper in tin all brands except tin of high purity.

The standard fully complies ST SEV 4809.

(Changed edition, Rev. N 1, 2).

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 dissolving the sample in a mixture of hydrochloric and nitric acids, binding of tin in complex with tartaric acid and photometric determination extracted in the chloroform layer of complex compound of copper and diethyldithiocarbamate lead on the spectrophotometer at a wavelength of 436 nm or photoelectrocolorimeter in the wavelength interval from 400 to 450 nm.

(Changed edition, Rev. N 2).

2.2 the Instrument, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

Separating funnel with a capacity of 500 and 50 cm.

The cylinders or tubes with ground stoppers.

Nitric acid according to GOST 4461 and diluted 1:2.

Hydrochloric acid according to GOST 3118.

A mixture of hydrochloric and nitric acids to dissolve the 3:1 ratio, freshly prepared.

Ammonia water according to GOST 3760.

Tartaric acid according to GOST 5817, solution: 40 g of tartaric acid dissolved in 100 cmof water.

Chloroform (trichlormethane).

Lead acetate according to GOST 1027.

Sodium N, N-diethyldithiocarbamate according to GOST 8864.

Diethyldithiocarbaminate lead, solution in chloroform of 0.4 g of lead acetate is dissolved in 50 cmof water and 0.4 g of sodium diethyldithiocarbamate dissolved in 50 cmof water. Solutions while stirring poured into a separatory funnel with a capacity of 500 cmand the resulting white precipitate of diethyldithiocarbaminate of lead is dissolved in 250 cmof chloroform by shaking the contents of the funnel for 1 min, the chloroform Layer transferred into another separating funnel and washed with 150−200 cmof water, shaking the contents of the funnel. After liquid-liquid separation, the chloroform layer decanted through ashless filter, dry in a dark, dry flask with a glass stopper.

Electrolytic copper according to GOST 859*.
______________
* On the territory of the Russian Federation GOST 859−2001, here and hereafter. — Note the manufacturer’s database.

Solutions of copper standard.

Solution a: 0,1000 g of copper is dissolved in 10 cmof nitric acid, diluted 1:2 and boil to remove oxides of nitrogen. The solution was then cooled, transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with water and mix.

1 cmof the solution contains 1·10g of copper.

Solution B is prepared on the day of application: 10,0 smsolution 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 1·10g of copper.

(Changed edition, Rev. N 1, 2

).

2.3 analysis

2.3.1. A portion of tin mass of 0.5 g was placed in a beaker with a capacity of 100 cmand dissolved in 10 cmof the mixture of acids to dissolve. The solution was evaporated to 2−3 cm, pour 3 cmof concentrated hydrochloric acid, 10 cmof a solution of tartaric acid and heated to dissolve the salts, and cooled.

When the mass fraction of copper of 0.01% the analysis was carried out using the whole solution. At higher concentration of copper solution is transferred to a volumetric flask with a capacity of 50 cm, adjusted to the mark with water, mix and take aliquot part of the solution as listed in table.1.

Table 1

Aliquot part of the solution placed in a beaker with a capacity of 50 cm, and the solution was adjusted to 10 cmof water (if the analysis is taken 5,0 cmof solution).

The solution is neutralized with ammonia to a pH of1 by universal indicator paper, transferred into a separating funnel with a capacity of 50 cmand a glass washed with 10 cmof water in three steps. The solution is poured precisely measured 10.0 cmof a solution of lead diethyldithiocarbamate in chloroform and shake for 2 min. After separation of the liquids, the organic layer decanted into a dry cylinder or tube with a glass stopper.

Optical density of the solution measured on a spectrophotometer at a wavelength of 436 nm or photoelectrocolorimeter using the filter with the area of light transmission in the wavelength range of from 430 nm to 450 nm and cuvettes with an optimum thickness of the layer.

Solution comparison is the solution of lead diethyldithiocarbamate in chloroform.

From the value of the optical density of the sample solution is subtracted the value of the optical density of the solution in the reference experiment and for the calibration schedule find the mass of copper in solution.

(Changed edition, Rev. N 1, 2, 3)

.

2.3.2. To build a calibration curve in seven of the eight glasses with a capacity of 50 cmmeasure 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 and 6.0 cmstandard solution B, which corresponds to 0,005; 0,01; 0,02; 0,03; 0,04; 0,05 and 0.06 mg of copper. All glasses poured 3 cmof hydrochloric acid, neutralized with ammonia to pH=1 and then analysis is conducted as in claim 2.3.1. Solution comparison is the solution not containing standard copper solution. According to the obtained values of optical density and corresponding mass fractions of copper to build the calibration graph.

(Changed edition, Rev. N 2).

2.4 Processing of results

2.4.1. Mass fraction of copper () in percent is calculated by the formula

,

where is the mass of copper was found in the calibration schedule g;

 — the weight of the portion of tin corresponding to the taken aliquote part of the solution,

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.2.

Table 2

3. ATOMIC ABSORPTION METHOD

3.1 the essence of the method

The method is based on dissolving the sample in a mixture of hydrofluoric and nitric acids with water and measuring the atomic absorption of copper in the flame acetylene-air at a wavelength of 324,7 nm.

(Changed edition, Rev. N 2).

3.2 Equipment, reagents and solutions

Spectrometer of atomic absorption.

The glasses are made of PTFE with a capacity of 50 cmor Cup platinum with a capacity of not less than 50 cm.

Nitric acid according to GOST 4461 and diluted 1:2.

Hydrofluoric acid according to GOST 10484.

Tin of high purity according to GOST 860.

Mix to dissolve; cook according to GOST 15483.2.

Copper according to the GOST 859.

The copper solution standard: 0,1000 g of copper is dissolved in 20 cmof nitric acid, diluted 1:2 and boil to remove oxides of nitrogen. The solution was cooled, transferred to a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 1·10g of copper.

(Changed edition, Rev. N 1, 2).

3.3 analysis

3.3.1. Depending on the mass fraction of copper in the sample tin weight in accordance with table.3 is placed in a beaker made of PTFE with a capacity of 50 cmor a platinum Cup and poured in small portions to 10 cmof the mixture for dissolution. Further analysis are as specified in GOST 15483.2.

Table 3

Fotometrirovanie is carried out at a wavelength of 324,7 nm under the conditions specified in GOST 15483.2.

The copper concentration set at the calibration schedule, fotometriya simultaneously with the analyzed solutions a series of solutions with known content of copper and Supervisory experience.

(Changed edition, Rev. 1, 2).

3.3.2. For construction of calibration curve six glasses of PTFE or platinum Cup is placed a portion of tin of high purity in accordance with the table.3, then dissolved in 10 cmof the mixture for dissolution, making sure that the reaction did not proceed rapidly. After dissolving the contents of the beaker heated for 1−2 minutes, without boiling, and cooled.

The resulting solutions are transferred to volumetric flask with a capacity of 50 cm. Five of them measure 0,4; 1,0; 1,5; 2,0 and 2,5 cmof a standard solution of copper, which corresponds to 0,04; 0,1; 0,15; 0,2 and 0,25 mg of copper, adjusted to the mark with water and mix.

Photometric solutions, as specified in clause 3.3.1.

According to the obtained average values of absorbance and known concentrations of copper to build the calibration graph.

(Changed edition, Rev. N 2).

3.4 processing of the results

3.4.1.Mass fraction of copper () in percent is calculated by the formula

,

where is the concentration fotometricheskogo solution, g/cm;

 — the concentration of copper in solution in the reference experiment, was found in the calibration schedule, g/cm;

 — volume fotometricheskogo solution, cm;

 — weight of tin, g

.

3.4.2. 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.

3.4.1, 3.4.2. (Changed edition, Rev. N 2).