GOST 12697.4-77

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  ГОСТ 12697.4-77

GOST 12697.4−77 Aluminum. Method for the determination of sodium (with Amendments No. 1, 2, 3)

GOST 12697.4−77

Group B59

INTERSTATE STANDARD

ALUMINIUM

Method for the determination of sodium

Aluminium. Method for determination of sodium

ISS 77.120.10
AXTU 1709

Date of introduction 1979−01−01

The decision of the State standards Committee of the Council of Ministers of the USSR from 27.09.77 N 2315 date of introduction is established 01.01.79

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

REPLACE GOST 12700−67 in part of sec. 2

EDITION with Amendments No. 1, 2, 3, approved in November 1981, November 1985, may 1988 (ICS 1−82, 2−86, 8−88).


This standard specifies the method of emission of flaming photometry for determination of sodium in aluminum (with a mass fraction of sodium from 0.001 to 0.05%).

The method is based on measuring the intensity of radiation of sodium in the flame of air-acetylene or air-propane-butane in nm.

(Changed edition, Rev. N 1, 3).

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis according to GOST 12697.1−77 and GOST 25086−87.

(Changed edition, Rev. N 3).

2. APPARATUS, REAGENTS AND SOLUTIONS

Photometer ardent for emission measurements ПЖ1 or similar type.

Laboratory scales according to GOST 24104−88* 2nd accuracy class with the weighing error of 0.0002 g.
________________
* From 1 July 2002 was put into effect GOST 24104−2001**.

** On the territory of the Russian Federation GOST R 53228−2008. — Note the manufacturer’s database.

Hydrochloric acid of high purity according to GOST 14261−77 (concentration of sodium should not be more than 0.01 mg/DM), diluted 1:1, 1:5.

Acetylene dissolved technical GOST 5457−75.

Propane-butane.

Aluminum brand А999 according to GOST 11069−74 (mass fraction of sodium should not be more than 0.001%).

Sodium chloride according to GOST 4233−77.

Mercury GOST 4658−73.

Nickel chloride according to GOST 4038−79, a solution with a mass fraction of 1%.

Distilled water (concentration of sodium should not be more than 0.01 mg/DM).

The solution-background; solution 1 is prepared as follows: chips of aluminum etched for 10 min in hydrochloric acid, diluted 1:5, washed in distilled water and dried at a temperature of 105−110 °C. Then take the two hanging at 10,00 g in two quartz flasks with a capacity of 400 cmwith reverse air refrigerator, pour 200 cmof hydrochloric acid diluted 1:1 and heated in a sand bath to dissolve the aluminium (to accelerate the dissolution of aluminium add a drop of metallic mercury or 2−3 drops of solution of chloride of Nickel). Then the contents of the flask was transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water, mixed and transferred to plastic dishes.

Solution 1 contained 20 g/lof aluminum.

Solution 2; is prepared as follows: a background solution 1 diluted with water twice.

Solution 2 contains 10 g/lof aluminum.

Solutions of sodium standard.

Solution A, prepared as follows: 2,5420 g of sodium chloride, previously calcined at 500 °C, dissolve in water, transfer the solution into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmof the solution contains 1 mg of sodium (Na).

Solution B is prepared as follows: into a measuring flask with a capacity of 100 cmis placed 10 cmsolution A, made up to the mark with water and mix.

1 cmof a solution contains 0.1 mg of sodium (Na).

Calibration solutions of sodium prepared as follows: into a measuring flask with a capacity of 200 cmplaced 100 cmof solution 1, add 10 cmto the standard solution, made up to the mark with water and mix. Get the calibration solution with a mass fraction of sodium of 0.05% relative to aluminum.

Calibration solutions with mass fractions of 0.025, 0,0125, 0,0063, and 0,0032 0,001% prepare serial dilution of twice the previous solution solution 2. For this five dry tubes with a pipette, take 100 cmof solution 2. In the first flask with the same pipette select a calibration solution with a mass fraction of sodium of 0.05% and stirred well. Get the calibration solution with a mass fraction of sodium 0,025%. Taking the same pipette into the second flask 100 cmof solution with a mass fraction of sodium 0.025% and stirring with a solution of 2, get the calibration solution with a mass fraction of sodium of 0.0125%. Similarly prepare the remaining solutions. The prepared solutions were stored in a quartz or plastic container.

(Changed edition, Rev. N 3).

3. ANALYSIS

3.1. Shavings of aluminium etched with hydrochloric acid diluted 1:5, washed with distilled water and dried at a temperature of 105−110 °C.

Weighed aluminium weighing 1 g is placed in a quartz flask with a capacity of 100−200 cmwith reverse air refrigerator or in a quartz glass with a capacity of 100−200 cm, covered with a quartz watch glass, add 20 cmof hydrochloric acid diluted 1:1, heated in a sand bath until complete dissolution of the sample. The solution was transferred to volumetric flask with a capacity of 100 cm, made up to the mark with water and mix. In the analysis of high purity metal to accelerate the dissolution it is necessary to add a drop of metallic mercury or 2−3 drops of chloride of Nickel.

(Changed edition, Rev. N 3).

3.2. Prepared calibration solutions and solutions of the investigated samples photometric at a wavelength of 589 nm. At the same time photometric solution 2, which is the control experiment for the calibration solutions and the solution obtained simultaneously with the preparation of samples from high-purity aluminium, which is the control experiment for the investigated samples.

After each measurement the water spray.

3.3. First photometric solution 2, then the calibration solutions solution reference experiment and researched solutions. Repeat the measurements in reverse order. Find the arithmetic mean of the emission intensity of sodium for each solution. From the thus obtained values subtracted for the calibration mixtures the emission intensity of solution 2, and the studied solutions, the emission intensity of the solution in the reference experiment.

3.4. Based on the obtained digital values of intensity of radiation and the known mass fraction of sodium in the calibration solutions graphical or mathematical method to find the mass percent of sodium in the samples.

(Changed edition, Rev. N 3).

3.5. Permissible discrepancies in the results of parallel definitions should not exceed the values given in the table.

(Changed edition, Rev. N 1, 3).