GOST 13938.3-78

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  ГОСТ 13938.3-78

GOST 13938.3−78 Copper. Method for the determination of phosphorus (with Amendments No. 1, 2, 3, 4)

GOST 13938.3−78

Group B59

INTERSTATE STANDARD

COPPER

Method of determination of phosphorus

Copper.
Method for determination of phosphorus

AXTU 1709

Date of introduction 1979−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

DEVELOPERS

G. P. Giganov, E. M. Peneva, A. A. Blyahman, E. D. Shuvalov, A. N. Savelieva

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 24.01.78 N 155

3. REPLACE GOST 13938.3−68

4. The standard corresponds to the international standard ISO 4741−84

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

_________________
* On the territory of the Russian Federation GOST 13047.9−2002, here and hereafter;
** On the territory of the Russian Federation GOST 859−2001, here and hereafter;
*** On the territory of the Russian Federation GOST 13047.9−2002, here and hereafter. — Note the manufacturer’s database.

6. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)

7. REPRINT (November 1999) with Amendments No. 1, 2, 3, 4, approved in March 1979, April 1983, June 1985, April 1988 (IUS 5−79, 7 to 83, 8−85, 7−88)


This standard sets the photometric method for the determination of phosphorus in copper grades according to GOST 859, except M00k and M00b (mass fraction in phosphorus from the 0.0003 to 0.06%).

The method is based on the formation of phosphorus-molybdenum-vanadium heteroalicyclic in 1 n nitric acid solution. Optical density of the solution measured at the wavelength or 440−453 400−413 nm depending on the content of phosphorus.

(Changed edition, Rev. N 4).

1. GENERAL REQUIREMENTS

General requirements for method of analysis and safety requirements when performing tests according to GOST 13938.1.

(Changed edition, Rev. N 4).

2. APPARATUS, REAGENTS AND SOLUTIONS

Photoelectrocolorimeter or spectrophotometer with all accessories.

Nitric acid according to GOST 4461 and diluted 2:1, 1:1, 1:5.

Ammonium undeviatingly meta GOST 9336, solution 2.5 g/l; prepared as follows: 2.5 g of ammonium anadalucia dissolved in 650 cmof water, add 10 cmof nitric acid and add water to 1 DM.

Ammonium molybdate according to GOST 3765, recrystallized a solution of 100 g/DM. The recrystallization is performed as follows: a sample of salt weighing 100−120 g dissolved in 400 cmof water at a temperature of 80 °C and filtered twice hot solution through a dense filter of «blue ribbon». To the solution was added 250 g of ethyl alcohol, cooled and allowed to settle for 1 h. Precipitated crystals was filtered on a Buechner funnel. Received ammonium molybdate solution, and again recrystallized, filtered on a Buchner funnel, washed 2−3 times with ethanol at 20−30 cm, after which they are dried in air. Before application of the recrystallized salt solution is prepared as follows: 100 g of salt was dissolved in 700−800 cmof water and add 25−30 cmof ammonia. Stirred to dissolve the sample, the solution was filtered into a measuring flask with volume capacity of 1000 cmthrough cotton or paper pulp, dilute to the mark with water and mix.

Hydrogen peroxide (perhydrol) according to GOST 10929 solution (1:9).

Potassium permanganate according to GOST 20490, solution 0,2 mol/l(1 n).

Copper according to the GOST 859.

Potassium phosphate according to GOST odnosemjannyj 4198, dried at 80−90 °C for 1 h.

Sodium phosphate disodium GOST 11773, dried at 102−105 °C.

The standard solutions of phosphorus.

Solution A, prepared as follows: 0,458 g twosemester phosphate of sodium or of single 0,439 g of potassium phosphate dissolved in 50−70 DMwater, add 2 cmof nitric acid, the solution transferred to 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 phosphorus.

Solution B is prepared as follows: 25 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.025 mg of phosphorus.

Solutions A and B freshly prepared and stored in a plastic container.

Hydrochloric acid according to GOST 3118 and diluted 1:1.

Ammonia water according to GOST 3760.

The technical rectified ethyl alcohol according to GOST 18300.

(Changed edition, Rev. N 2, 4).

3. ANALYSIS

3.1. Determination of phosphorus in the mass fraction of it less than 0,003%

A sample of copper with a mass of 5.0 g is placed in a beaker with a capacity of 250 cm, cover with a watch glass and dissolved in 30 cmof nitric acid, diluted 2:1 when heated, not allowing to boil (if necessary add the acid in portions of 10 cm). After dissolution of samples in low boiling and remove the nitrogen oxides without removing the watch glass. The solution was cooled, added 1 cmof solution of potassium permanganate and leave the solution for 5 min Then heated to boiling, boiled for 1 min and cooled to 30−40 °C. Add 2 cmof hydrogen peroxide diluted 1:9, boil for 1 min, add 5 cmof a solution of ammonium anadalucia and continue to boil for 1 min. the Solution was cooled and poured into a volumetric flask with a capacity of 50 cm. With constant stirring are added dropwise 5 cmof a solution of molybdate of ammonium. Next, the solution is topped up to the mark with water and mix.

After 20 minutes, measure the optical density of the solution at a wavelength 400−413 nm in cuvettes with the thickness of the absorbing layer 30 mm. with a Solution of comparison is the solution containing 5 g of copper and all reagents, except molybdate of ammonium.

At the same time carried out two test experience: 30 cmof nitric acid, diluted 2:1, evaporated to 3−4 cmand diluted with 25 cmof water. Then add 1 cmof solution of potassium permanganate and do as stated above in the determination of phosphorus in copper.

The comparison solution is a solution containing 3−4 cmof nitric acid, 25 cmwater and 5 cmof the solution vadeevaloo ammonium. The solution was boiled for 1 min, transferred to a volumetric flask with a capacity of 50 cmand top up with water to the mark.

The average value of the optical density of solutions of control experiments is subtracted from the value of the optical density of the analyzed solution. The amount of phosphorus set by the calibration schedule, constructed as described in section 3.4.1.

(Changed edition, Rev. N 2).

3.2. Determination of phosphorus in the mass concentration from 0,002 to 0,006%

The determination is carried out according to claim 3.1, however, the measurement of the optical density of the solution is performed in cuvettes with a layer thickness of 20 mm, and the amount of phosphorus set by the calibration schedule, constructed as described in section 3.4.2.

3.3. Determination of phosphorus at a mass fraction from 0.001 to 0.06 percent

A sample of copper with a mass of 2.0 g was placed in a conical flask with a capacity of 100 cm, 18−20 cm, pour themixture of hydrochloric and nitric acids in the ratio 1:3 and heated to remove oxides of nitrogen, avoiding boiling point of the solution. Then add 20−25 cmof water and boil for 3−4 min. Cool and place the solution in a volumetric flask with a capacity of 50 cm.

To the obtained solution poured with stirring 5 cmsolution vadeevaloo ammonium and 5 cmof ammonium molybdate solution, dilute to the mark with water and mix. After 5 min measure the optical density of the solution at a wavelength of 400−453 nm in a cuvette with a layer thickness of 30 mm. with a Solution of comparison is the solution not containing ammonium molybdate.

The mass of phosphorus determined according to the calibration schedule.

(Added, Rev. N 4).

3.3. Determination of phosphorus in the mass fraction of from 0.005 to 0.06 percent

A sample of copper with a mass of 2.0 g was placed in a beaker with a capacity of 250 cm, and dissolved in 30 cmof nitric acid, diluted 2:1, not boiling if heated. After dissolution of copper at a low boil and remove the nitrogen oxides without removing the watch glass. Add 2 cmof hydrogen peroxide diluted 1:9, and boil for 30 seconds, then add 10 cmof a solution vadeevaloo ammonium and boil for 1 min.

The solution was cooled and poured into a volumetric flask with a capacity of 100 cm.

Add 10 cmof molybdate ammonium solution with continuous stirring. Solution in a volumetric flask immediately topped up to the mark with water and mix. After 20 minutes, measure the optical density of the solution at a wavelength of 440−453 nm in a cuvette with a layer thickness of 30 mm.

Solution comparison in the measurement of the optical density is a solution containing 2 g of copper (with a mass fraction of phosphorous is less than 0.0005%) and all reagents.

The mass of phosphorus in the solution set for the calibration graphics constructed as described in section 3.4.3.

3.4. Construction of calibration curve

3.4.1. For the mass concentration of phosphorus less than 0,003%

In a volumetric flask with a capacity of 50 cmplaced 0; 1,0; 2,0; 3,0; 4,0; 5,0 and 6.0 cmstandard solution B, which corresponds to 0; 25; 50; 75; 100; 125 and 150 µg phosphorus, add 3−4 cmof nitric acid, add water to volume of 30−35 cm, pour 5 cmof a solution of ammonium anadalucia 5 cmof molybdenic acid ammonium solution and add water to the mark. After the addition of each solution during perelivania of molybdate ammonium solution the contents of the tubes mixed well. After 20 minutes, measure the optical density of the solutions at the wavelength 400−413 nm in a cuvette with a layer thickness of 30 mm relative to the solution without added phosphorus.

3.4.2. When the mass fraction of phosphorus from 0.002 to 0,006% do the same as in section 3.4.1, however, the amount of standard solution B is 0; 2; 4; 6; 8; 10 and 12 cm, which corresponds to 0; 50; 100; 150; 200; 250 and 300 µg phosphorus.

The optical density of solutions measured at a wavelength 400−413 nm in cuvettes with a layer thickness of 20 mm relative to the solution without added phosphorus.

3.4.3. When the mass fraction of phosphorus from 0.005 to 0.06% in eight cups with a capacity of 250 cmweigh 2.00 g of copper, add 0; 1,0; 2,5; 5,0; 7,5; 10,0; 12,0; 13,0 cmof solution A, which corresponds to 0; 100; 250; 500; 750; 1000; 1200; 1300 mcg phosphorus. Then dissolved in 30 cmof nitric acid and then act as described in claim 3.3.

The values of optical densities found in PP.3.4.1−3.4.3, and their respective contents of phosphorus build calibration graphs.

(Changed edition, Rev. N 2).

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of phosphorus () in percent is calculated by the formula

,

where is the mass of phosphorus was found in the calibration schedule, mcg;

 — weight of copper,

4.2. Discrepancies in the results of two parallel measurements and the two tests should not exceed the values given in the table.

(Changed edition, Rev. N 4).

4.3. Allowed determination of phosphorus GOST and GOST 741.8 13047.5.

(Added, Rev. N 4).


APP. (Deleted, Rev. N 4).