GOST 9816.5-2014

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  ГОСТ 9816.5-2014

GOST 9816.5−2014 Tellurium technical. Method of atomic-absorption analysis

GOST 9816.5−2014

INTERSTATE STANDARD

TELLURIUM TECHNICAL

Method of atomic-absorption analysis

Tellurium technical. Method of atomic-absorptive analysis

ISS 77.120.99

Date of introduction 2016−01−01

Preface

Goals, basic principles and main procedure of works on interstate standardization established in GOST 1.0−92 «interstate standardization system. Basic provisions» and GOST 1.2−2009 «interstate standardization system. Interstate standards, rules and recommendations on interstate standardization. Rules of development, adoption, renewal and cancellation"

Data on standard

1 DEVELOPED by the Open joint-stock company «Scientific-research and design Institute of enrichment and mechanical processing of minerals «URALMEKHANOBR» (JSC «uralmekhanobr»), Technical Committee for standardization TC 368 «Copper"

2 as AMENDED by the Federal Agency for technical regulation and Metrology

3 ACCEPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 72-P of 14 November 2014)

The standard was accepted by voting:

4 by Order of the Federal Agency for technical regulation and Metrology from 02 APR 2015 N 208-St inter-state standard GOST 9816.5−2014 introduced as the national standard of the Russian Federation from January 01, 2016

5 REPLACE GOST 9816.5−84


Information about the changes to this standard is published in the annualreference index «National standards», and the text changes and amendments — in monthly information index «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in the monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet

1 Scope

This standard specifies a method of measuring the mass fraction of copper, iron, lead, selenium, silver technical tellurium by atomic-absorption spectroscopy in the ranges given in table 1.


Table 1

Percentage

2 Normative references

The present standard features references to the following international standards:

GOST 859−2001 Copper. Brand

GOST 1770−74 (1042−83 ISO, ISO 4788−80) Glassware volumetric laboratory glass. Cylinders, beakers, flasks, test tubes. General specifications

GOST 3118−77 Reagents. Hydrochloric acid. Specifications

GOST 3778−98 Lead. Specifications

GOST 4461−77 Reagents. Nitric acid. Specifications

GOST 5457−75 Acetylene, dissolved and gaseous. Specifications

GOST 6709−72 distilled Water. Specifications

GOST 6836−2002 Silver and alloys on its basis. Brand

GOST 9816.0−2014 Tellurium technical. General requirements for methods of analysis

GOST 9849−86 iron Powder. Specifications

GOST 20448−90 liquefied hydrocarbon Gases fuel for household consumption. Specifications

GOST 24104−2001laboratory 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 29169−91 (ISO 648−77) oils. Pipette with one mark

GOST 29227−91 (ISO 835−1-81) oils. Pipettes are graduated. Part 1. General requirements

GOST ISO 5725−6-2002Accuracy (correctness 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 5725−1-2002 «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 in the annual information index «National standards» published as on January 1 of the current year, and the editions of the monthly information index «National standards» for 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.

3 Characteristics of measurement accuracy

A measure of the accuracy of measuring the mass fraction of copper, iron, lead, selenium, silver corresponds to the characteristics given in table 2 (at P =0,95).

Limit values of repeatability and reproducibility of the measurement at a confidence probability P =0.95 is shown in table 2.


Table 2 — Values of the measure of the accuracy, limits of repeatability and reproducibility of measurements of mass fraction of copper, iron, lead, selenium, silver at a confidence probability P =0,95

Percentage

4 measurement Means, auxiliary devices, materials, solutions

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

spectrometer of atomic absorption with flame atomizer and the radiation sources for copper, iron, lead, selenium, silver;

— air compressor;

— scale special accuracy class according to GOST 24104;

slab heating [1], ensuring the heating temperature up to 350 °C or equivalent;

— bath water;

glass hour;

— volumetric flasks 2−25−2, 2−50−2, 2−100−2, 2−250−2, 2−500−2, 2−1000−2 according to GOST 1770;

— glasses-1−100 TCS, GOST 25336;

— flasks KN-2−100−19/26 KN-2−250−19/26 TCS GOST 25336;

pipettes not lower than 2nd accuracy class according to GOST and GOST 29169 29227.

When taking measurements, use the following products and solutions:

— air compressed under a pressure of 2·10-6·10PA;

— acetylene according to GOST 5457;

— propane-butane according to GOST 20448;

— distilled water according to GOST 6709;

— hydrochloric acid according to GOST 3118, diluted 1:1 and the molar concentration of 2 mol/l, 4 mol/l, 6 mol/DM;

— nitric acid according to GOST 4461, diluted 1:3 and 2:1;

— a mixture of hydrochloric and nitric acids 3:1 and 1:3;

— lead according to GOST 3778, marks S0 and S1;

— copper according to the GOST 859;

— iron according to GOST 9849;

— silver GOST 6836;

— selenium metal, high purity [2].

Note:

1 allowed the use of other measuring instruments of the approved type, auxiliary devices and materials, technical and metrological characteristics are not inferior to mentioned above.

2 allowed the use of reagents produced by other normative documents, provided that their metrological characteristics of measurement results, given in this standard.

5 the essence of the method

The method is based on measuring absorption of atomic resonance lines of copper, iron, lead, selenium, silver at the wave lengths specified in table 3 after the introduction of the analyzed solution in the flame acetylene-air or propane-butane-air.


Table 3 — wavelengths

6 Preparation for measurements

6.1 Preparation of solutions of known concentration

6.1.1 Preparation of solutions of copper

In preparing the solution And the mass concentration of copper of 1 mg/cm: a sample of copper weighing 1 g is placed in a conical flask with a capacity of 250 cm, is dissolved in a volume of 25 to 30 cmof a mixture of hydrochloric and nitric acids (3:1) under heating and the solution is evaporated to dryness. The residue is treated twice with a volume of 7 to 10 cmof hydrochloric acid, evaporating the solution every time dry. The dry residue is dissolved in a volume of 100 to 120 cmof hydrochloric acid diluted 1:1, boil to dissolve the salt, cooled and transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

In the preparation of a solution with a mass concentration of copper is 0.1 mg/cmof the sample solution And 50 cmplaced in a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

6.1.2 Preparation of solutions of iron

In preparing the solution And the mass concentration of iron is 1 mg/cm: a sample of iron weighing 1 g is placed in a conical flask with a capacity of 250 cm, is dissolved in a volume of 10 to 15 cmof a mixture of hydrochloric and nitric acids (3:1) under heating and the solution is evaporated to dry salts. Poured from 100 to 120 cmof hydrochloric acid diluted 1:1, boiled for 5 to 7 minutes, cool and transfer the solution into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

In the preparation of a solution with a mass concentration of iron to 0.1 mg/cmof the sample solution And 10 cmis placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

6.1.3 Preparation of solutions of lead

In preparing the solution And the mass concentration of lead of 1 mg/cma sample of lead with a mass of 1.0 g was placed in a conical flask with a capacity of 250 cm, flow 10 to 15 cmof nitric acid, diluted 1:3 when heated and evaporated up to wet salts. Poured from 5 to 7 cmof nitric acid, transfer the solution into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

In the preparation of a solution with a mass concentration of lead of 0.1 mg/cma 10 cm aliquotof solution A is placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

6.1.4 Preparation of solutions of selenium

In preparing the solution And the mass concentration of selenium of 1 mg/cma portion of the selenium mass 0.1 g is placed in a conical flask with a capacity of 100 cm, flow 10 to 15 cmof nitric acid by heating the solution is evaporated to dryness. Pour 20 cmof hydrochloric acid, cool, transfer the solution into a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

In the preparation of a solution with a mass concentration of selenium of 0.1 mg/cma 10 cm aliquotof solution A is placed in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

6.1.5 Preparation of solutions of silver

In preparing the solution And the mass concentration of silver is 0.1 mg/cma sample of silver with a mass of 0.1 g was placed in a conical flask with a capacity of 250 cm, flow 20 to 25 cmof nitric acid, diluted 1:3 under heating and the solution is evaporated to wet salts. Pour 50 to 60 cmof water, cool, transfer the solution into a measuring flask with volume capacity of 1000 cm, made up with hydrochloric acid, the molar concentration of 6 mol/DMup to the mark and mix.

In the preparation of a solution with a mass concentration of silver 0.01 mg/cma 10 cm aliquotof solution A is placed in a volumetric flask with a capacity of 100 cm, made up with hydrochloric acid, the molar concentration of 2 mol/DMup to the mark and mix.

6.2 Construction of calibration graphs

In seven volumetric flasks with a capacity of 100 cmplaced: 0,25; 0,5; 1,0; 3,0; 4,0; 5,0 and 6.0 cmB solutions of copper, iron, lead, selenium, silver, dilute to the mark with hydrochloric acid molar concentration of 2 mol/DM, or 4 mol/land stirred.

The resulting solutions injected into the flame of acetylene-air atomic absorption spectrophotometer and measure the absorption component at the appropriate wavelength (table 3).

Note — Concentrations of the calibration solutions are for guidance only and depend on the characteristics of the used atomic absorption spectrometer, the interval defined concentrations. For constructing a calibration curve allowed to use from 3 to 7 calibration solutions, but not less than 3.

The abscissa shows the delay of mass concentration defined component in the calibration solution, expressed in milligrams per cubic centimeter, and the y — axis the corresponding values of the analytical signals.


Note — it is allowed to Express the concentration of the calibration solutions in other mass units.

7 performance measurement

7.1 General requirements for the method of measurement and safety requirements when performing measurements according to GOST 9816.0.

7.2 Suspension of tellurium weighing from 1 to 2 g (depending on the mass fraction of the component and the sensitivity of the instrument) is placed in a conical flask with a capacity of 250 cmor a glass with a capacity of 100 cm. Into the flask pour 40 to 50 cmof a mixture of hydrochloric and nitric acids (1:3), and dissolved by heating to obtain a volume of 3 to 5 cm. Poured from 5 to 10 cmof hydrochloric acid, from 10 to 20 cmof water and heated to dissolve the salts. In a glass poured from 7 to 10 cmof nitric acid, diluted 2:1, cover the watch glass and slightly heated at a temperature of from 30 °C to 40 °C to dissolve the sample. The solution was then heated in a water bath to remove oxides of nitrogen. Glass glass is removed, wash it with water above the glass and to the obtained solution poured from 5 to 10 cmof hydrochloric acid and heated to dissolve the salts.

The solution was cooled and placed in a volumetric flask with a capacity from 25 to 250 cm, made up to the mark with hydrochloric acid molar concentration of 2 mol/DM(decomposition in the flask) and 4 mol/DM(decomposition in a glass) and stir.

The analyzed solution is injected into the flame of acetylene-air atomic absorption spectrophotometer and measure the absorption component at the appropriate wavelength (table 3). The absorbance of each solution is measured at least twice and for calculating take arithmetic mean value. When changing solutions, the spray system was washed with water to obtain the zero readings.

The recommended maximum value of measured absorbance of approximately 0.5 units. If necessary to reduce its value is allowed to carry out measurements at less sensitive wavelengths or deploy the burner.

The found value of the absorbance of the analyzed solution minus the absorbance of the blank solution experience find the mass concentration of the component defined by the calibration schedule. If the concentration of the analyte in the test solution exceeds the concentration in solutions to construct the calibration curve (the value of absorbance of the analyzed solution above absorption of the last points of the graph), carried out a dilution of the test solution. For this, an aliquot of the analyzed solution is placed in a flask with a capacity of 100 cm, pour the hydrochloric acid to create the acidity is 5% by volume, made up to the mark with water and mix.

Be used for the atomization of sample flame propane-butane-air, if the differences between parallel determinations match those listed in table 2.

8, the Processing of the measurement results

8.1 Mass fraction of component , %, is calculated by the formula

, (1)

where is the mass concentration of the component was found in the calibration schedule, taking into account the value of the idle experience, mg/cm;

 — the volume of the analyzed solution, cm;

 — the weight of the portion of the sample,

8.2 Mass fraction component (additional dilution), %, is calculated by the formula

, (2)

where is the mass concentration of the component was found in the calibration schedule, taking into account the value of the idle experience, mg/cm;

 — the volume of the analyzed solution, cm;

 — the final volume of the analyzed solution, cm;

 — volume aliquot of the solution, cm;

 — the weight of the portion of the sample,

8.3 For the measurement result taking the arithmetic mean of two parallel definitions, provided that the absolute difference between them in terms of repeatability does not exceed the value (at confidence probability P=0,95) repeatability limit rgiven in table 2.

If the difference between the highest and lowest results of parallel measurements exceeds the limit value of the frequency of occurrence, perform the procedure described in [3] (paragraph 5.2.2.1).

8.4 Discrepancies between the results of measurements obtained in two laboratories, should not exceed the values of the limit of reproducibility shown in table 2. In this case, the final result may be decided to their arithmetic mean value. At default of this condition can be used the procedures outlined in [3].

Bibliography

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* The one referred to here and hereinafter, not shown. For additional information, please refer to the link;
** Access to international and foreign documents mentioned here can be obtained by clicking on the link to the site shop.cntd.ru. — Note the manufacturer’s database.