GOST 13047.16-2014

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  ГОСТ 13047.16-81

GOST 13047.16−2014 Nickel. Cobalt. Methods for determination of cadmium

GOST 13047.16−2014

Group B59

INTERSTATE STANDARD

NICKEL. COBALT

Methods for determination of cadmium

Nickel. Cobalt. Methods for determination of cadmium

ISS 77.120.40
AXTU 1732

Date of introduction 2016−01−01

Preface

Goals, basic principles and procedure of works on interstate standardization have been 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, application, renewal and cancellation"

Data on standard

1 DEVELOPED by Interstate technical committees for standardization MTK 501 Nickel and MTC 502 «Cobalt"

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

3 ACCEPTED by the Interstate Council for standardization, Metrology and certification (Protocol of October 20, 2014 N 71-N)

The adoption voted:

4 by Order of the Federal Agency for technical regulation and Metrology of June 24, 2015 N 816-St inter-state standard GOST 13047.16−2014 introduced as the national standard of the Russian Federation from 1 January 2016.

5 REPLACE GOST 13047.16−2002


Information about the changes to this standard is published in the annual reference 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 establishes the atomic absorption methods for the determination of cadmium (at a mass fraction of cadmium from 0.00001% to 0,0030%) in the primary Nickel GOST 849, Nickel powder according to GOST 9722 and GOST cobalt 123 on.

2 Normative references

This standard uses the regulatory references to the following standards:

GOST 123−2008 Cobalt. Specifications

GOST 849−2008 Nickel primary. Specifications

GOST 1467−93 Cadmium. Specifications

GOST 4461−77 Reagents. Nitric acid. Specifications

GOST 5457−75 Acetylene, dissolved and gaseous. Specifications

GOST 9722−97 Nickel Powder. Specifications

GOST 10157−79 Argon gaseous and liquid. Specifications

GOST 11125−84 nitric Acid of high purity. Specifications

GOST 13047.1−2014 Nickel. Cobalt. General requirements for methods of analysis

GOST 22860−93 Cadmium high purity. Specifications

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 General requirements and safety requirements

General requirements for methods of analysis used by the quality of distilled water and laboratory glassware and safety at work — according to GOST 13047.1.

4 Atomic absorption method with electrothermal atomization

4.1 Method of analysis

The method is based on measuring absorption at a wavelength of 228,8 nm resonance radiation by atoms of cadmium resulting from the electrothermal atomization of the sample solution.

4.2 measuring instruments, auxiliary devices, materials, reagents and solutions

Atomic absorption spectrometer for measurements with electrothermal atomization, the correction non-selective absorption and the automated flow of the solution into the atomizer.

Lamp with hollow cathode for the excitation of spectral lines of cadmium.

Argon gas according to GOST 10157.

Filters obestochennye [1] or other filter medium density.

Nitric acid according to GOST 4461, if necessary, purified by distillation, or according to GOST 11125, diluted 1:1, 1:9 and 1:19.

Nickel powder according to GOST 9722 or standard sample of Nickel, for example [2], pre-installed (certified) mass fraction of cadmium, not more than 0,00001%.

Cobalt GOST 123 or standard sample of cobalt, for example, [3], pre-installed (certified) mass fraction of cadmium, not more than 0,00001%.

Cadmium GOST 1467 or GOST 22860.

Cadmium solutions of known concentration.

The solution And the mass concentration of cadmium 0.0001 g/cmis prepared as follows: a portion of the cadmium mass 0,1000 g placed in a beaker with a capacity of 250 cm, flow 15 to 20 cmof nitric acid, diluted 1:1, dissolved by heating, boil for 3−5 minutes, cooled, transferred to a measuring flask with volume capacity of 1000 cm, 50 cm pournitric acid, diluted 1:1, and adjusted to the mark with distilled water.

Solution B mass concentration of cadmium 0,00001 g/cmis prepared as follows: into a measuring flask with a capacity of 100 cmtransfer 10 cmof solution A and bring to the mark with nitric acid, diluted 1:19.

Solution of the mass concentration of cadmium 0,000001 g/cmis prepared as follows: into a measuring flask with a capacity of 100 cmtransfer 10 cmof solution B and bring to the mark with nitric acid, diluted 1:19.

The solution G of the mass concentration of cadmium 0,0000002 g/cmis prepared as follows: into a measuring flask with a capacity of 100 cm andstand 20 cmsolution and adjusted to the mark with nitric acid, diluted 1:19.

4.3 Preparation for analysis

4.3.1 To construct a calibration chart 1 in determining the mass fraction of cadmium not more than 0,00010% sample of Nickel powder or cobalt or of a standard sample of composition of Nickel or cobalt with a mass of 1,000 grams are placed in tumblers or flasks with a capacity of 250 cm. The number of batches must match the number of points of calibration curve, including Supervisory experience.

The batches of the Nickel powder or cobalt or of a standard sample of composition of Nickel or cobalt poured from 15 to 20 cmof nitric acid, diluted 1:1 and dissolved by heating. When using the Nickel powder in the slurries was filtered through a filter (red or white ribbon), washed two or three times with nitric acid, diluted 1:9. The filter is washed two or three times with hot distilled water. The solutions were evaporated to a volume of 5 to 7 cm, flow from 40 to 50 cmof distilled water, heated to boiling, cooled and transferred to volumetric flasks with a capacity of 100 cm.

In the flask transfer 0,5; 1,0; 2,0; 4,0 and 5,0 cmof the solution In the flask with the solution in the reference experiment, the solution containing cadmium, not poured, adjusted to the mark with distilled water and measure the absorbance in accordance with 4.4.

The mass of cadmium in the calibration solutions is of 0.0000001; 0,0000002; 0,0000004; 0,0000008 and 0,0000010 G.

4.3.2 For the construction of calibration curve 2 in determining the mass fraction of cadmium more than 0,00010% sample of Nickel powder or cobalt or of a standard sample of composition of Nickel or cobalt with a mass of 0,500 g was placed in beakers or flasks with a capacity of 250 cm. The number of batches must match the number of points of calibration curve, including Supervisory experience.

Sample of Nickel powder or cobalt or of a standard sample of composition of Nickel or cobalt is dissolved in accordance with 4.3.1. In volumetric flasks transfer 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 and 6.0 cmof solution B. the flask with the solution in the reference experiment, the solution containing cadmium, not poured, adjusted to the mark with distilled water and measure the absorbance in accordance with 4.4.

The mass of cadmium in the calibration solutions is 0,0000005; 0,0000010; 0,0000020; 0,0000030; 0,0000040; 0,0000050 and 0,0000060 G.

4.4 analysis

A portion of the sample with a mass of 1,000 g (with mass fraction of cadmium not more than 0,00010%) or weighing 0,500 g (for the mass concentration of cadmium more than 0,00010%) are placed in tumblers or flasks with a capacity of 250 cm, flow 15 to 20 cmof nitric acid, diluted 1:1, evaporated to a volume of 5 to 7 cm, transferred to a volumetric flask with a capacity of 100 cm, cooled and adjusted to the mark with distilled water.

The absorbance of the sample solution and the calibration solutions at a wavelength of 228,8 nm, slit width is not more than 1.0 nm with a correction non-selective absorption in the current of argon is measured at least two times, sequentially spraying them in an atomizer. Depending on the type of spectrometer select the optimal volume of the solution from 0.005 to 0.050 cmor optimal time, aerosol spray from 5 to 50 C. Washed the spray system with distilled water, check the zero point and the stability of the calibration curve. To check the zero point solution is used, the appropriate control experience, prepared in accordance with 4.3.

Selection of optimal temperature regimes for the atomizer is carried out individually for the used spectrometer for the calibration solutions.

Recommended operating conditions of the atomizer shown in table 1.


Table 1 — operating conditions of the atomizer

The values of absorption of the calibration solutions and corresponding masses of cadmium build the calibration graph.

The value of absorbance of sample solution find the mass of cadmium in the calibration schedule.

4.5 Processing the analysis results

Mass fraction of cadmium in the sample X, %, calculated by the formula:

, (1)

where is the mass of cadmium in the sample solution, g;

 — the weight of the portion of the sample,

4.6 accuracy Control analysis

Control of accuracy of analysis results is carried out according to GOST 13047.1.

The regulations control the precision — limits of repeatability and reproducibility and increased control precision — the expanded uncertainty of the results of the analysis are shown in table 2.


Table 2 — Specifications control precision — limits of repeatability and reproducibility and increased control precision — the expanded uncertainty of the results of the analysis at a confidence probability P=0,95

Percentage

5 Atomic absorption method with flame atomization (at a mass fraction of cadmium from from 0.0002% to 0,0030%)

5.1 Method of analysis

The method is based on measuring absorption at a wavelength of 228,8 nm resonance radiation by atoms of cadmium resulting from atomization when spraying the sample solution in flame acetylene-air.

5.2 measurement Means, auxiliary devices, materials, reagents and solutions

Atomic absorption spectrometer for measurements in the flame acetylene-air.

Lamp with hollow cathode for the excitation of spectral lines of cadmium.

Acetylene gas according to GOST 5457.

Filters obestochennye [1] or other filter medium density.

Nitric acid according to GOST 4461, if necessary, purified by distillation, or according to GOST 11125, diluted 1:1,1:9 and 1:19.

Nickel powder according to GOST 9722 or standard sample of Nickel, for example [2], pre-installed (certified) mass fraction of cadmium is not more than 0,0002%.

Cobalt GOST 123 or standard sample of cobalt, for example, [3], pre-installed (certified) mass fraction of cadmium is not more than 0,0002%.

Cadmium GOST 1467 or GOST 22860.

Cadmium solutions of known concentration.

The solution And the mass concentration of cadmium 0.0001 g/cmat 4.2.

Solution B mass concentration of cadmium 0,00001 g/cmat 4.2.

5.3 Preparation for assay

For constructing the calibration curve sample of Nickel powder or cobalt or of a standard sample of composition of Nickel or cobalt with a mass of 3,000 g were placed in beakers or flasks with a capacity of 250 cm. The number of batches must match the number of points of calibration curve, including Supervisory experience.

The batches of the Nickel powder or cobalt or of a standard sample of composition of Nickel or cobalt go from 25 to 30 cmof nitric acid, diluted 1:1 and dissolved by heating. When using the Nickel powder in the solutions were filtered through filters (red or white ribbon), washed two or three times with nitric acid, diluted 1:9. The filters are washed two or three times with hot distilled water. The solutions were evaporated to a volume of 10 to 15 cm, flow from 40 to 50 cmof distilled water, heated to boiling, cooled and transferred to volumetric flasks with a capacity of 100 cm.

In the flask is transferred 0,5; 1,0; 2,0; 4,0; 6,0; 8,0 and 10.0 cmof solution B. the flask with the solution in the reference experiment, the solution containing cadmium, not poured, adjusted to the mark with distilled water and measure the absorbance in accordance with 5.4.

The mass of cadmium in the calibration solutions is 0,000005; 0,000010; 0,000020; 0,000040; 0,000060; 0,000080 and 0,000100 G.

5.4 analysis

A portion of the sample with a mass of 3,000 g were placed in a glass or flask with a capacity of 250 cm, flow 25 to 30 cmof nitric acid, diluted 1:1, dissolved by heating, boil for 2−3 min, evaporated to a volume of 15 to 20 cm, pour the distilled water from 50 to 60 cm, cooled, transferred to a volumetric flask with a capacity of 100 cmand adjusted to the mark with distilled water.

The absorbance of the sample solution and the calibration solutions at a wavelength of 228,8 nm, slit width is not more than 1.0 nm is measured at least two times, sequentially spraying them in the flame acetylene-air, spray rinsed the system with distilled water, check the zero point and the stability of the calibration curve. To check the zero point of the solution is used in the reference experiment, prepared in accordance with 5.3.

The values of absorption of the calibration solutions and corresponding masses of cadmium build the calibration graph.

The value of absorbance of sample solution find the mass of cadmium in the calibration schedule.

5.5 Processing of analysis results

Mass fraction of cadmium in the sample X, %, is calculated by the formula (1).

5.6 Control of accuracy of analysis

Control of accuracy of analysis results is carried out according to GOST 13047.1.

The regulations control the precision — limits of repeatability and reproducibility and increased control precision — the expanded uncertainty of the results of the analysis are shown in table 2.

Bibliography