GOST 9816.3-84

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  ГОСТ 9816.3-84

GOST 9816.3−84 Tellurium technical. Methods for the determination of sulfur (with Amendments No. 1, 2, 3)

GOST 9816.3−84

Group B59

STATE STANDARD OF THE USSR

TELLURIUM TECHNICAL

Methods of determining sulphur

Technical tellurium. Methods for determination of sulphur

AXTU 1709

Valid from 01.07.85
before 01.07.90

The decision of the State Committee USSR on standards on June 27, 1984 N 2149 validity period is set with 01.07.85 before 01.07.90*
________________
* Expiration removed by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (I & C N 4, 1994). — Note the manufacturer’s database.


REPLACE GOST 9816.3−74


MADE: the Change in N 1, approved and put into effect by the Decree of Gosstandart of the USSR from 14.05.1986 N 1229 c 01.11.1986; Modification No. 2, approved and put into effect by the Decree of Gosstandart of the USSR from 20.12.1989 N c 3908 01.07.1990; Amendment No. 3, approved and put into force by the Order of Rosstandart from 26.11.2014 No. 1772-St c 01.09.2015

Change N 1, 2, 3 are made by the manufacturer of the database in the text IUS N 8, 1986, IUS N 3, 1990, IUS N 3, 2015

This standard specifies photojournalistically method for the determination of sulphur (when the mass fraction of sulfur from 0.001 to 0.1%) and gravimetric method for the determination of sulfur (with sulfur mass fraction of from 0.1 to 0.6%) in the technical tellurium.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 9816.0−84.

1A. NORMATIVE REFERENCES

This standard uses the regulatory references to the following international standards:

GOST 83−79 Reagents. Sodium carbonate. Specifications

GOST 1277−75 Reagents. The silver nitrate. Specifications

GOST 1770−74 laboratory Glassware measuring glass. Cylinders, beakers, flasks, test tubes. General specifications

GOST 3118−77 Reagents. Hydrochloric acid. Specifications

GOST 3760−79 Reagents. The aqueous ammonia. Specifications

GOST 3777−76 Reagents. Barium nitrate. Specifications

GOST 4108−77Reagents. Barium chloride 2-water. Specifications
________________
On the territory of the Russian Federation GOST 4108−72, here and hereafter. — Note the manufacturer’s database.


GOST 4145−74 Reagents. Potassium sulphate. Specifications

GOST 4233−77 Reagents. Sodium chloride. Specifications

GOST 4461−77 Reagents. Nitric acid. Specifications

GOST 6259−75 Reagents. Glycerin. Specifications

GOST 6709−72 distilled Water. Specifications

GOST 9147−80 Glassware and equipment lab porcelain. Specifications

GOST 9816.0−84 Tellurium technical. General requirements for methods of analysis

GOST 12026−76 laboratory filter Paper. Specifications

GOST 20288−74 Reagents. The carbon tetrachloride. Specifications

GOST 24104−2001* laboratory Scales. General technical requirements
_______________
* On the territory of the Russian Federation GOST R 53228−2008 «Scales non-automatic actions. Part 1. Metrological and technical requirements. Test».

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

GOST ISO 5725−6-2003** Accuracy (trueness and precision) of methods and measurement results. Part 6. The use of precision values in practice
_______________
** On the territory of the Russian Federation GOST R ISO 5725−6-2002 «Accuracy (trueness and precision) of methods and measurement results. Part 6. The use of precision values in practice».


Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet or published annually by the information sign «National standards» published as on January 1 of the current year and related information published monthly indexes published in the current year. If the reference standard is replaced (changed), when using this standard should be guided by replacing (amended) standard. If the reference standard is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.

(Added, Rev. N 3).

1B. CHARACTERISTICS OF INDICATORS OF MEASUREMENT ACCURACY

A measure of the accuracy of measuring the mass fraction of sulfur corresponds to the characteristics given in table 1 (if of 0.95).

Limit values of repeatability and reproducibility of measurements for a confidence probability of 0.95 is given in table 1.


Table 1 — values of the indicator of measurement accuracy, limits of repeatability and reproducibility of measurement with confidence probability of 0.95

Percentage

(Added, Rev. N 3).

2. PHOTOJOURNALISTICALLY METHOD

The method is based on the formation of a suspension of barium sulfate in the interaction of barium ions with sulfate ions and measuring the intensity of the turbidity of the solution. As a stabilizer of the slurry is used glycerin.

2.1. Measurement means, auxiliary devices, materials, solutions

When performing measurements using the following measuring instruments and auxiliary devices:

— spectrophotometer or photoelectrocolorimeter with all accessories necessary for measurements at a wavelength of 364 nm;

— the stove is electric with a closed heating element for temperature up to 400 °C;

— special laboratory scales of accuracy class according to GOST 24104;

— volumetric flasks 2−25−2, 2−100−2 according GOST 1770;

— flasks KN-1−100−24/29 TCS, KN-1−200−24/29 TCS GOST 25336;

— glasses-1−100 TCS-1−200 TCS-1−1000 TCS according to GOST 25336;

— crucibles filter type TF-32-PORT 16 TCS with GOST 25336;

— a Buchner funnel 1 according to GOST 9147;

— hour glass.

When performing measurements, use the following materials, solutions:

— distilled water according to GOST 6709;

— nitric acid according to GOST 4461;

— hydrochloric acid according to GOST 3118, diluted 1:1;

the anhydrous sodium carbonate according to GOST 83, a solution with a mass concentration of 100 g/DM;

— barium chloride according to GOST 4108, a solution with a mass concentration of 100 g/DM;

— glycerin according to GOST 6259, a solution of 100 g/DM;

— potassium sulphate according to GOST 4145, recrystallized;

the filter paper according to GOST 12026;

filters obestochennye [1] or similar."

(Changed edition, Rev. N 1, 3).

2.1. Preparations for the measurements

2.1.1. For the preparation of recrystallized potassium sulfate: potassium sulfate sample weight of 100 g was placed in a beaker with a capacity of 1000 cm1000 cm pouredwater and dissolved by heating. The undissolved residue is filtered from the hot solution into the filter crucible (or Buchner funnel), the remainder is discarded. The filtrate is evaporated until crystals and cooled. The formed crystals filtered on a filter crucible (or Buchner funnel), transferred to a porcelain Cup and dried at a temperature from 70 °C to 100 °C for 1−1,5 hours the Cup with the crystals cooled and repeat the recrystallization. The resulting salt crystals from the second recrystallization was dried at room temperature.

2.1.2. Construction of calibration curve

For construction of calibration curve prepare solutions of sulfur.

In preparing the solution And the mass concentration of sulphur 0.1 mg/cma sample of potassium sulfate mass 0,0544 g placed in a beaker with a capacity of 100 cm, flow 50 to 60 cmof water was placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

In the preparation of a solution of mass concentration of sulphur of 0.01 mg/cm10 cmsolution And placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

Solution B is stable for two days.

2.1.3. Construction of calibration curve

In seven volumetric flasks with a capacity of 25 cmis placed 0; 0,5; 2,0; 4.0, 6.0 and 8.0 cmof solution B, 1 cmof solution A, which corresponds to 0,0; 0,005; 0,02; 0,04; 0,06; 0,08 and 0.1 mg of sulphur, flow from 3.5 to 4 cmof hydrochloric acid diluted 1:1, 10 cmwater 10 cmof a solution of glycerine and mix. Then pour 3 to 3.5 cmof barium chloride, made up to the mark with water and mix. After 30−40 minutes the solution is again stirred and measure the optical density of the solution at a wavelength of 364 nm in a cuvette with the thickness of the light absorbing layer was 50 mm. In a solution of comparison used water. Calibration curve building given in the reference experiment (reference solution with zero concentration of sulfur).

2.1 a (Introduced later, Rev. N 3).

2.2. Analysis

2.2.1. A portion of the tellurium by weight 0.1−0.5 g were placed in a glass (flask) with a capacity of 100−200 cm, pour 1−2 cmof sodium carbonate solution and 10−15 cmof nitric acid. Glass (the bulb) cover the watch glass and leave you without heat until the cessation of the violent reaction. Then the solution was boiled to remove oxides of nitrogen, remove the glass, wash over the glass (bulb) and the solution was evaporated to dryness at a moderate heat to prevent any splashing of the sample.

To the dry residue poured 4−4,5 cmof hydrochloric acid, 5−7 cmof water and heated to dissolve the salts. The solution is then kept in a warm place plate for 1−1,5 hours.

After cooling, the solution was placed in a volumetric flask with a capacity of 25 cm, add 1 cmof a solution of hydrochloric acid (1:1), 10 cmof a solution of glycerine and mix. Then pour 3−3. 5 cmof a solution of barium chloride, diluted to the mark with water and mix.

After 30−40 min the solution is mixed again and measured the optical density on the photoelectrocolorimeter, using a filter with maximum transmittance at a wavelength of 364 nm and a cuvette with a layer thickness of 50 mm. Solution of comparison is water.

The mass of sulphur is determined according to the calibration schedule.

(Changed edition, Rev. N 1, 3).

2.2.2. (Changed edition, Rev. N 1); (Deleted, Rev. N 3).

2.3. Processing of the results

2.3.1. Mass fraction of sulfur (X) in percent is calculated by the formula

,

where is the mass of sulfur was found in the calibration graphics mg;

 — the volume of solution in a volumetric flask, cm;

 — volume aliquote part of the solution, cm;

m — weight of tellurium, g;

 — the mass of sulfur in solution in the reference experiment, was found in the calibration graphics mg;

1000 — conversion factor of milligrams to grams.

(Changed edition, Rev. N 3).

2.3.2. The measurement results take the arithmetic mean of two parallel definitions, provided that the absolute difference between them in terms of repeatability does not exceed the values (with confidence probability of 0.95) limit of repeatability in table 1.

If the discrepancy between the results of parallel measurements exceeds the limit value of the frequency of occurrence, perform the procedure described in GOST ISO 5725−6 (paragraph 5.2.2.1).

(Changed edition, Rev. N 2, 3).

3. GRAVIMETRIC METHOD

The method is based on the allocation of sulfur in the form of sulfate ions with a solution of nitrate of barium, and weighing the resulting precipitate. Pre-sulfur should be separated from interfering elements by extraction with a mixture of tributyl phosphate with carbon tetrachloride.

3.1. Measurement means, auxiliary devices, materials, solutions

When performing measurements using the following measuring instruments and auxiliary devices:

— the stove is electric with a closed heating element for temperature up to 350 °C;

— special laboratory scales of accuracy class according to GOST 24104;

— drying Cabinet, providing a heating temperature of from 100 °C to 105 °C;

oven muffle with heating temperature up to 1000 °C;

— bath water;

— volumetric flasks 2−1000−2 according GOST 1770;

— flasks KN-2−100−29/32 KN-2−250−29/32 according to GOST 25336;

— glasses-1−250 TCS according to GOST 25336;

— funnel filtering laboratory according to GOST 25336;

— separating funnel VD-1−50 TC GOST 25336;

— porcelain crucibles according to GOST 9147;

— dryer 2−100 according to GOST 25336;

— hour glass.

When taking measurements, use the following products and solutions:

— distilled water according to GOST 6709;

— nitric acid according to GOST 4461;

— hydrochloric acid according to GOST 3118;

sodium chloride according to GOST 4233, solution of molar concentration 0.1 mol/DM;

— barium nitrate according to GOST 3777, saturated solution;

— silver nitrate according to GOST 1277, solution mass concentration of 0.1 g/DM;

— carbon tetrachloride according to GOST 20288;

— ammonia according to GOST 3760;

— tributyl [2];

— a mixture of tributyl phosphate with carbon tetrachloride in the ratio 3:7;

— methyl orange indicator [3], a solution of 0.01 g/DM;

filters obestochennye [1] or similar;

the filter paper according to GOST 12026, brands f, FS.

(Changed edition, Rev. N 2, 3).

3.1. Preparations for the measurements

3.1.1. In the preparation of sodium chloride solution of molar concentration 0.1 mol/DMpre-dried at a temperature of 120 °C to constant weight weighed salt weight 5,8440 g placed in a beaker with a capacity of 250 cm, dissolved in 100−150 cmof water, the solution is poured into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix. The solution was stored in a flask with a glass stopper.

(Added, Rev. N 3).

3.2. The measurement results take the arithmetic mean of two parallel definitions, provided that the absolute difference between them in terms of repeatability does not exceed the values (with confidence probability of 0.95) limit of repeatability in table 1.

If the discrepancy between the results of parallel measurements exceeds the limit value of the frequency of occurrence, perform the procedure described in GOST ISO 5725−6 (paragraph 5.2.2.1).

(Changed edition, Rev. N 3).

3.3. Processing of the results

3.3.1. Mass fraction of sulfur (X) in percent is calculated by the formula

,

where is the mass of the precipitate of barium sulfate, g;

0,1373 — factor for recalculation of mass of barium sulfate on sulfur;

m — weight of tellurium,

3.3.2. Allowable absolute differences of the results of two parallel measurements at p = 0.95 does not exceed the values given in the table.

3.3.2. The absolute value allowable discrepancies between the two measurement results obtained in different laboratories, should not exceed the limit values for the reproducibility given in table 1 at a confidence level of 0.95. At default of this condition can be used the procedure set out in GOST ISO 5725−6.

(Added, Rev. N 3).

3.3.3. The difference between the largest and smallest results of two parallel measurements with a confidence probability P=0.95 does not exceed the allowable absolute values of the differences given in the table

(Changed edition, Rev. N 2).

Bibliography

Bibliography (added, Rev. N 3).