GOST 1293.2-83

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  ГОСТ 1293.2-83

GOST 1293.2−83 lead-antimony Alloys. Methods for determination of copper (with Amendments No. 1, 2)

GOST 1293.2−83*
______________________
* The designation of the standard.
Changed the wording, Rev. N 2.

Group B59

STATE STANDARD OF THE USSR

LEAD-ANTIMONY ALLOYS

Methods for determination of copper

Lead-antimony alloys. Methods for the determination of copper

AXTU 1709*
________________

* Changed the wording, Rev. N 1.

Valid from 01.07.83
prior to 01.07.88*
_______________________________
* Expiration removed by Protocol No. 7−95
The interstate Council for standardization,
Metrology and certification (I & C N 11, 1995). -
Note the manufacturer’s database.

DEVELOPED by the Ministry of nonferrous metallurgy of the USSR

PERFORMERS

A. P. Sychev, M. G. Sun, L. I. Maksay, R. D. Kogan

INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

Member Of The Board Of A. P. Snurnikov

APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on standards of February 8, 1983 N 706

REPLACE GOST 1293.2−74

MADE: the Change in N 1, approved and put into effect by the Decree of the USSR State Committee for standards from 20.11.87 N 4205 from 01.07.88, Change No. 2 adopted by the Interstate Council for standardization, Metrology and certification (minutes N 13 dated 28.05.98). The state developer of Kazakhstan. By the resolution of Gosstandart of Russia from 11.04.2001 N 173-St introduced on the territory of the Russian Federation from 01.01.2002

Change N 1, 2 made by the manufacturer of the database in the text IUS N 2, 1988, ICS # 7, 2001

This standard establishes photometric methods for determination of copper when the mass fraction of copper from 0.001 to 0.6% of lead-antimony alloys.

(Changed edition, Rev. N 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 1293.0−83.

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF COPPER WITH CUPRIZONE

2.1. The essence of the method

The method is based on formation of blue coloured complex compounds of bivalent copper with cuprizone at pH 9 and subsequent measurement of optical density at a wavelength of 595 nm.

2.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer.

Nitric acid GOST 4461−77 diluted 1:1.

Sulfuric acid GOST 4204−77, diluted 1:1 and 1:49.

Ammonia water according to GOST 3760−79 diluted 1:1.

Rectified ethyl alcohol GOST 18300−87.

Cuprizone (bicyclohexyl-oxalidaceae).

Citric acid according to GOST 3652−69.

Copper GOST 859−78*, mark M0.
______________
* On the territory of the Russian Federation GOST 859−2001. Here and further. — Note the manufacturer’s database.

(Changed edition, Rev. N 2).

2.3. Preparation for assay

2.3.1. Preparation of standard solutions of copper

Solution a: 1,0000 g of copper is dissolved in 20 cmof nitric acid (1:1). The solution was boiled to remove oxides of nitrogen, transferred to a measuring flask with volume capacity of 1000 cm. After cooling, the solution was adjusted to the mark with water and mix.

1 cmof solution A contains 1.0 mg of copper.

Solution B: 10 cmsolution And transferred into a measuring flask with volume capacity of 1000 cm, adjusted to the mark with water and mix.

1 cmof a solution contains 0.01 mg of copper.

(Changed edition, Rev. N 2).

2.3.2. Preparation of 0.5% alcohol solution cuprizone: 0.5 g cuprizone dissolved by heating in 100 cmof ethanol.

2.3.3. Preparation of buffer solution with pH 9: 300 g of citric acid dissolved in 300 cmof water is added 400 cmof ammonia solution, transferred to a measuring flask with volume capacity of 1000 cm, adjusted to the mark with water and mix.

2.3.4. To build a calibration curve in six of the seven volumetric flasks with a capacity of 50 cmeach flow 1, 3, 5, 8, 10 and 12 cmof solution B, which corresponds to 10, 30, 50, 80, 100 and 120 ág of copper. In the seventh flask and the solution would not flow. Bring the volume of each solution with water to 20 cm, and add ammonia solution dropwise until a pH of 9 to universal indicator paper. Add 10 cmof buffer solution and 3 cmof a solution cuprizone. After addition of each reagent solutions are mixed, then bring to the mark with water. After 30−40 min measure the optical density of each solution at a wavelength of 595 nm on the spectrophotometer or in a region of wavelengths 590−610 nm on a photoelectrocolorimeter. Solution comparison is the solution not containing standard copper solution.

According to the obtained values of optical density of the solutions and the corresponding content of copper to build the calibration graph.

(Changed edition, Rev. N 1).

2.4. Analysis

2.4.1. A portion of the alloy weight 1,0000 g is placed in a conical flask with a capacity of 250 cm, and dissolved in 20 cmof a solution of nitric acid.

After dissolution, the flask content was evaporated to wet salts. To the residue add 50 cmof water and 10 cmof sulphuric acid solution (1:1), boiled for 10 min and left for 2 h. the Solution was filtered through a dense filter, washed several times with sulphuric acid solution (1:49), collecting the filtrate and washings in a conical flask with a capacity of 250 cm, and evaporated to a volume of 20 cm. The solution was cooled, adjusted with ammonia solution to pH 9 to universal indicator paper and add a 10 cmbuffer solution. To the obtained solution are added 2 cmcuprizone solution, the solution transferred to a volumetric flask with a capacity of 50 cm, adjusted to the mark with water and mix.

If the mass fraction of copper in the alloy exceeds 0.01%, the filtrate and the washings collected in a conical flask with a capacity of 250 cm, neutralized with ammonia solution to pH 7 and transferred to a volumetric flask with a capacity of 250 cm. From the solution taken aliquot part, as specified in accordance with table.1. Aliquot part of the solution was transferred to a volumetric flask with a capacity of 50 cm, add ammonia solution dropwise until a pH of 9 to universal indicator paper, then 10 cmof buffer solution and 2 cmof mortar cuprizone. After each addition of the reagent the solution was stirred. The resulting solution was adjusted to the mark with water and mix.

Table 1

After 30−40 min measure the optical density of the solution at a wavelength of 595 nm on the spectrophotometer or in a region of wavelengths 590−610 nm on a photoelectrocolorimeter. Solution comparison is the solution of the reference experiment.

Mass of copper found by the calibration schedule.

(Changed edition, Rev. N 1, 2).

2.5. Processing of the results

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

,

where is the mass of copper in the sample solution, found by calibration schedule, mcg;

 — volume of initial solution, cm;

 — weight alloy, g;

 — volume aliquote part of the solution, cm.

2.5.2. The discrepancy between the results of parallel measurements (the difference between the largest and smallest results of parallel measurements) and the discrepancy between the results of the analysis (the difference between the larger and the smaller of the results of the analysis) at a confidence level =0.95 does not exceed the permissible values of absolute differences are given in table.2.

Table 2

The control accuracy of the analysis is carried out using standard samples or by other methods stipulated by GOST 1293.0−83.

The error analysis results (at a confidence probability =0,95) does not exceed the limit values given in table.2, if the following conditions are true: the discrepancy between the results of parallel measurements does not exceed the permissible, the results of the monitoring of the accuracy of positive analysis.

(Changed edition, Rev. N 2).

2.5.3. The method used in the disagreement in assessing the quality of the alloy.

3. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF COPPER AND DIETHYLDITHIOCARBAMATE LEAD

3.1. The essence of the method

The method is based on photometric determination of copper by the yellow color it diethyldithiocarbamate complex. Optical density of the solution is measured at a wavelength of 436 nm.

(Changed edition, Rev. N 1, 2).

3.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer with all accessories.

Nitric acid GOST 4461−77 diluted 1:1.

Tartaric acid according to GOST 5817−77, a solution of 500 g/DM.

Lead acetate according to GOST 1027−67.

Chloroform (trichlormethane), distilled or carbon tetrachloride according to GOST 20288−74.

Copper GOST 859−78 marks M0.

Sodium N, N-diethyldithiocarbamate according to GOST 8864−71.

(Changed edition, Rev. N 2).

3.3. Preparation for assay

3.3.1. Preparation of standard solutions of copper

Solution a: 0,1000 g of copper is dissolved in 5 cmof nitric acid (1:1), dilute with water to 50−60 cm, boil to remove oxides of nitrogen, transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof solution A contains 0.1 mg of copper.

Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

1 cmof a solution contains 0.002 mg of copper.

(Changed edition, Rev. N 2)

.

3.3.2. Preparation of the solution of lead diethyldithiocarbamate in chloroform or carbon tetrachloride

0.2 g of lead acetate dissolved in 100 cmwater; 0.2 g of sodium diethyldithiocarbamate and dissolved in 100 cmof water and filtered through a dense filter. Then a solution of acetate of lead transferred to a separatory funnel with a capacity of 300 cm, add 2 cmof a solution of sodium diethyldithiocarbamate, 10 cmof chloroform or carbon tetrachloride and shaken out with 1 min. If the layer of chloroform or carbon tetrachloride are brown, discard it. The extraction is repeated until, until the layer of chloroform or carbon tetrachloride becomes colorless. Then to the contents of the funnel pour the entire solution of sodium diethyldithiocarbamate, 100 cmof chloroform or carbon tetrachloride and shaken for 1 min. Extraction is repeated three times, adding 100 cmof chloroform or carbon tetrachloride and each time merging a layer of chloroform or of carbon tetrachloride in a dry volumetric flask with a capacity of 1000 cm. The volume in the volumetric flask was adjusted to the mark with chloroform or carbon tetrachloride and mix well; the solution is kept in a dark bottle for a long time.

(Changed edition, Rev. N 2).

3.3.3. To build a calibration curve in six of the seven separatory funnels with a capacity of 100 cmselect 1, 2, 3, 4, 5 and 6 cmof solution B, which corresponds to 2, 4, 6, 8, 10 and 12 mcg of copper. The seventh funnel, the solution is not administered. Poured in the funnel all the water up to 20 cm, 25 cmsolution of lead diethyldithiocarbamate in chloroform or carbon tetrachloride and shake for 1 min. the Extracts decanted into a clean dry flask with a capacity of 50 cm. After 10 minutes measure the optical density of the extracts in the region of wavelengths at 430−455 nm or photoelectrocolorimeter at a wavelength of 436 nm on the spectrophotometer. Solution comparison is chloroform or carbon tetrachloride.

According to the obtained values of optical density of the extracts (minus the optical density of the solution, which was not administered the standard copper solution) and their corresponding grades of copper to build the calibration graph.

3.4. Analysis

A portion of the alloy weight 1,0000 g when the mass fraction of copper of 0.02% or 0,5000 g when the mass fraction of copper in excess of 0.02% is placed in a conical flask with a capacity of 250 cmand dissolved with slow heating in 20 cmof nitric acid (1:1) supplemented with 2 cmof a solution of tartaric acid, cover the flask with a watch glass. Then remove the watch glass, the solution was boiled to remove oxides of nitrogen, cooled and transferred to volumetric flask with a capacity of 100 or 500 cm.

The solutions were diluted to the mark with water and mix. Depending on the mass fraction of copper taken aliquot part of the solution in accordance with the table.3 and placed in a separating funnel with a capacity of 100 cm.

Table 3

Pour water up to 20 cm. From the burette is poured into the same separating funnel 25 cmof a solution of lead diethyldithiocarbamate in chloroform or carbon tetrachloride and shake for 1 min. the Organic layer decanted into a clean dry flask with a capacity of 50 cmand after 10 min measure the optical density of the solution in the region of wavelengths of 430−455 nm on or photoelectrocolorimeter at a wavelength of 436 nm on the spectrophotometer.

A solution of comparison is used, chloroform or carbon tetrachloride.

Mass of copper found by the calibration schedule.

3.3.3, 3.4. (Changed edition, Rev. N 1, 2).

3.5. Processing of the results

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

,

where is the mass of copper in the sample solution, found by calibration schedule, mcg;

 — the mass of copper in solution in the reference experiment, was found in the calibration schedule, mcg;

 — volume of initial solution alloy, cm;

 — weight alloy, g;

 — volume aliquote part of the solution, cm

.

3.5.2. The discrepancy between the results of parallel measurements (the difference between the largest and smallest results of parallel measurements) and the discrepancy between the results of the analysis (the difference between the larger and the smaller of the results of the analysis) at a confidence level =0.95 does not exceed the permissible values of absolute differences are given in table.2.

The control accuracy of the analysis is carried out using standard samples or by other methods stipulated by GOST 1293.0−83.

The error analysis results (at a confidence probability =0,95) does not exceed the limit values given in table.2, if the following conditions are true: the discrepancy between the results of parallel measurements does not exceed the permissible, the results of the monitoring of the accuracy of positive analysis.

(Changed edition, Rev. N 2).