GOST 9853.14-96

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  ГОСТ 9853.14-96

GOST 9853.14−96 Titan spongy. Method for determination of magnesium

GOST 9853.14−96

Group B59

INTERSTATE STANDARD

TITANIUM SPONGE

Method for determination of magnesium

Sponge titanium.
Method for determination of magnesium

ISS 77.120*
AXTU 1709
____________________
* In the index «National standards» in 2007.
77.120 ISS and ISS 77.120.50. — Note the manufacturer’s database.

Date of introduction 2000−07−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 105, Ukrainian research and design Institute of titanium

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 9 dated April 12, 1996)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated 19 October 1999 No. 353-St inter-state standard GOST 9853.14−96 introduced directly as state standard of the Russian Federation from July 1, 2000.

4 INTRODUCED FOR THE FIRST TIME

1 Scope

This standard establishes the atomic absorption method for the determination of magnesium (with a mass fraction of magnesium from 0.001% to 0.1%) in the spongy titanium according to GOST 17746.

The method is based on measuring atomic absorption of magnesium in the flame acetylene-air at a wavelength of RUB 285.2 nm. The determination is carried out by standard addition.

2 Normative references

The present standard features references to the following standards:

GOST 8.315−97 State system for ensuring the uniformity of measurements. The standard samples. The main provisions, the order of development, certification, approval, registration and application

GOST 804−93 primary Magnesium ingots. Specifications

GOST 4517−87 Reagents. Methods for the preparation of accessory reagents and solutions used in the analysis

GOST 5457−75 Acetylene, dissolved and gaseous. Specifications

GOST 11125−84 nitric Acid of high purity. Specifications

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 17746−96 spongy Titanium. Specifications

GOST 23780−96 spongy Titanium. Methods of sampling and sample preparation

GOST 25086−87 non-ferrous metals and their alloys. General requirements for methods of analysis

GOST 25336−82 Glassware and equipment laboratory glass. The types, basic parameters and dimensions

3 General requirements

3.1 General requirements for the method of analysis according to GOST 25086.

3.2 Selection and preparation of samples is carried out according to GOST 23780.

3.3 Mass fraction of magnesium is determined in two batches.

4 measuring instruments and auxiliary devices

Spectrophotometer of atomic absorption with the source of radiation spectral lines of magnesium.

Acetylene according to GOST 5457.

Nitric acid according to GOST 11125.

Hydrochloric acid according to GOST 14261, diluted 1:1 and 1:99.

Magnesium brand Мг96 according to GOST 804.

Standard samples according to GOST 8.315.

Titanium sponge grade TG-100 GOST 17746.

Bidistilled water, prepared according to GOST 4517, tested for purity by magnesium; the magnesium concentration is not higher 0,00005 g/cm. Store in a plastic container.

Conical flasks with a capacity of 100 cm, volumetric flasks with a capacity of 100 cmand 1000 cmfrom pritertymi or plastic tubes according to GOST 25336.

Standard solutions of magnesium.

Solution a: 0.1 g of magnesium metal is placed in a beaker with a capacity of 300 cm, flow 10 cmof water, 30 cmof hydrochloric acid (1:1) and lead dissolution initially at room temperature and then under heating. The solution was cooled to room temperature, transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix; best to use within 3 months.

1 cmof the solution contains 0.0001 g of magnesium.

Solution B: 5 cmsolution And placed in a volumetric flask with a capacity of 100 cm, is poured a solution of hydrochloric acid (1:99) to the mark and mix; prepare before use.

1 cmof solution B contains 0,000005 g of magnesium.

5 procedures for measuring

5.1 the sample the sample weight of 0.5−1.0 g was placed in a conical flask with a capacity of 100 cm, 70 cm pour thehydrochloric acid solution (1:1), beaker cover watch glass or funnel glass and lead dissolving when heated, keeping the volume of the solution in the flask about 50 cmby the addition of the same solution of hydrochloric acid.

After complete dissolution of the sample is added dropwise nitric acid until the disappearance of the violet color of the solution and boiled for 3−5 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

To prepare the solution in the reference experiment in the conical flask with a capacity of 100 cmis placed 70 cmof a hydrochloric acid solution (1:1), heated to boiling, add 3−4 drops of nitric acid and boiled for 3−5 min. the solution was Then cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

Before measuring the atomic absorption of the sample solutions and control experience to produce the construction of calibration curve or the graduation of the instrument, if it works in automatic mode.

Solution comparison is the solution of the reference experiment

.

5.2 Construction of calibration curve

5.2.1 When the mass fraction of magnesium from 0.001% to 0.003% in six conical flasks with a capacity of 100 cmplaced at 1.0 g of sponge titanium with a magnesium content less than 0.001% and conduct dissolution as specified in 5.1.

The solutions were transferred to volumetric flasks with a capacity of 100 cm, in five out of six volumetric flasks add 1,0; 1,5; 2,0; 2,5; 3,0 cmstandard solution B, which corresponds to the mass concentration of the added magnesium 0,000050; 0,000075; 0,000100; 0,000125; 0,000150 mg/cm.

The sixth solution of the flask is a solution of titanium.

5.2.2 When the mass fraction of magnesium in excess of 0.003% to 0.01% in six conical flasks with a capacity of 100 cmis placed 0.5 g of sponge titanium with a magnesium content less than 0.001% and conduct dissolution as specified in 5.1.

The solutions were transferred to volumetric flasks with a capacity of 100 cm, in five out of six volumetric flasks add 3,0; 5,0; 6,0; 8,0; 10,0 cmstandard solution B, which corresponds to the mass concentration of the added magnesium 0,00015; 0,00025; 0,00030; 0,00040; 0,00050 mg/cm.

The sixth solution of the flask is a solution of titanium.

5.2.3 When the mass fraction of magnesium above 0.01% to 0.03% in five conical flasks with a capacity of 100 cmis placed 0.5 g of sponge titanium with a magnesium content less than 0.001% and conduct dissolution as specified in 5.1.

The solutions were transferred to volumetric flasks with a capacity of 100 cm, in four of the five volumetric flasks add 0,50; 0,75; 1,00; 1,50 cmstandard solution A, which corresponds to the mass concentration of the added magnesium 0,00050; 0,00075; 0,00100; 0,00150 mg/cm.

The fifth solution of the flask is a solution of titanium.

5.2.4 When the mass fraction of magnesium in excess of 0.03% to 0.1% in six conical flasks with a capacity of 100 cmis placed 0.5 g of sponge titanium with a magnesium content less than 0.001% and conduct dissolution as specified in 5.1.

The solutions were transferred to volumetric flasks with a capacity of 100 cm, in five out of six volumetric flasks add 1,5; 2,0; 3,0; 4,0; 5,0 cmstandard solution A, which corresponds to the mass concentration of the added magnesium 0,0015; 0,0020; 0,0030; 0,0040; 0,0050 mg/cm.

The sixth solution of the flask is a solution of titanium.

5.2.5 the Solutions in all flasks is poured to the mark with water, mixed and sprayed in the flame acetylene-air in the following sequence: solution the reference experiment, a solution of titanium and in order of increasing concentration of the magnesium solutions containing additives of a standard solution of magnesium. Measurement of atomic absorption of magnesium is carried out at a wavelength of RUB 285.2 nm.

From the values of atomic absorption solutions containing the administered amount of a standard solution of magnesium, subtract the value of atomic absorption of a solution of titanium. According to the obtained values of the difference between of atomic absorption and corresponding values of mass concentration of magnesium added (mg/cm) build a calibration curve.

Mass concentration of magnesium in solution in the reference experiment and the sample is calculated according to the calibration schedule.

5.3 Calibrating spectrophotometer

5.3.1 In the case when the instrument is in automatic mode and made it to graduation, a charge of titanium sponge containing magnesium less than 0.001% by weight according to 5.2.1−5.2.4 is placed in four conical flasks with a capacity of 100 cmand conduct dissolution as specified in 5.1. The solutions were transferred to volumetric flasks with a capacity of 100 cm.

5.3.2 When the mass fraction of magnesium from 0.001% to 0.003% in three of the four volumetric flasks with a capacity of 100 cmwith solutions of titanium, prepared according to 5.3.1 add 1,0; 2,0; 4,0 cmstandard solution B, which corresponds to the mass concentration of the added magnesium 0,00005; 0,00010; 0,00020 mg/cm.

The solution to the fourth flask is a solution of titanium.

5.3.3 When the mass fraction of magnesium in excess of 0.003% to 0.01% in three of the four volumetric flasks with a capacity of 100 cmwith solutions of titanium, prepared according to 5.3.1 add 2,5; 5,0; 10,0 cmstandard solution B, which corresponds to the mass concentration of the added magnesium 0,000125; 0,000250; 0,000500 mg/cm.

The solution to the fourth flask is a solution of titanium.

5.3.4 for the mass concentration of magnesium above 0.01% to 0.03% in three of the four volumetric flasks with a capacity of 100 cmwith a solution of titanium prepared according to 5.3.1 add 0.5; 1,0; 2,5 cmstandard solution A, which corresponds to the mass concentration of the added magnesium 0,0005; 0,0010; 0,0025 mg/cm.

The solution to the fourth flask is a solution of titanium.

5.3.5 When the mass fraction of magnesium in excess of 0.03% to 0.1% in three of the four volumetric flasks with a capacity of 100 cmwith solutions of titanium, prepared according to 5.3.1 add 1,25; 2,5; 5,0 cmstandard solution A, which corresponds to the mass concentration of the added magnesium 0,00125; 0,00250; 0,00500 mg/cm.

The solution to the fourth flask is a solution of titanium.

5.3.6 the Solutions in all flasks is poured to the mark with water, mixed and sprayed in the flame acetylene-air in the following sequence: a solution of titanium, then in ascending order of the concentration of the magnesium solutions containing additives of a standard solution of magnesium, a solution of the reference experiment and the sample solution.

Measurement of atomic absorption of magnesium is carried out at a wavelength of RUB 285.2 nm.

6 Processing of measurement results

Mass fraction of magnesium in % is calculated by the formula

, (1)

where is the mass concentration of magnesium in the sample solution, corresponding to its atomic absorption, mg/cm;

mass concentration of magnesium in solution in the reference experiment corresponds to its atomic absorption, mg/cm;

 — the volume of the sample solution, cm;

 — the weight of the portion,

7 the Permissible error of measurement

7.1 the discrepancy between the measurement results and analysis results (at a confidence probability of 0.95) shall not exceed the permissible values given in table 1.


Table 1

Percentage

7.2 accuracy Control of the results of the analysis carried out according to standard sample in accordance with GOST 25086.

Allowed to monitor the accuracy of analysis results by the method of additives in accordance with GOST 25086.

Additives are standard solutions A or B.

8 qualifications

To perform analysis allowed the analyst qualification not less than 4th level.