GOST 13047.18-2014

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  ГОСТ 13047.18-81

GOST 13047.18−2014 Nickel. Cobalt. Methods for determination of arsenic

GOST 13047.18−2014

INTERSTATE STANDARD

NICKEL. COBALT

Methods for determination of arsenic

Nickel. Cobalt. Methods for determination of arsenic

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 13047.18−2014 introduced as the national standard of the Russian Federation from 1 January 2016.

5 REPLACE GOST 13047.18−2002


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 specifies the spectrophotometric and atomic absorption methods for the determination of arsenic (if arsenic mass fraction of from 0.0001% to 0,010%) in the primary Nickel GOST 849, Nickel powder according to GOST 9722 and GOST cobalt 123 on. As an arbitration method is atomic absorption method.

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 3118−77 Reagents. Hydrochloric acid. Specifications

GOST 3760−79 Reagents. The aqueous ammonia. Specifications

GOST 3765−78 Reagents. Ammonium molybdate. Specifications

GOST 3773−72 Reagents. The ammonium chloride. Specifications

GOST 4204−77 Reagents. Sulphuric acid. Specifications

GOST 4232−74 Reagents. The potassium iodide. Specifications

GOST 4328−77 Reagents. Sodium hydroxide. Specifications

GOST 4461−77 Reagents. Nitric acid. Specifications

GOST 5841−74 Reagents. Hydrazine sulfate

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 14261−77 hydrochloric Acid of high purity. Specifications

GOST 17746−96 spongy Titanium. Specifications

GOST 18300−87 ethyl rectified technical. Specifications

GOST 20288−74 Reagents. The carbon tetrachloride. Specifications

GOST 20490−75 Reagents. Potassium permanganate. Specifications

GOST 24147−80 aqueous Ammonia of 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 a spectrophotometric method

4.1 Method of analysis

The method is based on measuring light absorption at a wavelength of 610 nm or 840 solution of arsenic-molybdenum complex compound, the recovered sulfuric acid with hydrazine. Pre-allocate arsenic on iron hydroxide from ammonia environments, and then by extraction with carbon tetrachloride in the form of godenovo complex compounds from hydrochloric acid medium.

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

Spectrophotometer or photoelectrocolorimeter, which provides measurements in the wavelength range from 600 to 850 nm.

Filters obestochennye [1] or other dense filters.

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

Hydrochloric acid according to GOST 3118, if necessary, purified by distillation, or according to GOST 14261, diluted 1:1.

Sulfuric acid according to GOST 4204, diluted 1:1, 1:3 and 1:15.

Ammonia water according to GOST 3760, if necessary, cleaned, or according to GOST 24147, diluted 1:19.

Sodium hydroxide according to GOST 4328, solution mass concentration of 0.04 g/cm.

Ammonium chloride according to GOST 3773.

Ethyl alcohol according to GOST 18300.

Ammonium molybdate according to GOST 3765, recrystallized, solution mass concentration of 0.01 g/cm.

The recrystallized ammonium molybdate is prepared as follows: a sample of ammonium molybdate with a mass of 70.0 g were placed in a glass with a capacity of 600 or 1000 cm, pour 400 cmof distilled water, dissolved by heating from 70 °C to 80 °C, filtered through a filter (white or blue ribbon), heated and filtered again. To the hot solution was poured 250 cmof ethyl alcohol, cooled, kept for at least 1 h and filtered off the crystalline precipitate in the porcelain filtering funnel. The precipitate is washed two or three times with ethanol at 20−30 cmand dried in air.

Hydrazine sulfate according to GOST 5841, solution mass concentration of hydrazine sulfate 0.0015 g/cm.

The reaction mixture was prepared as follows: into a measuring flask with a capacity of 100 cmpour 50 cmof a solution of molybdate of ammonium, 5 cmof hydrazine sulfate and adjusted to the mark with distilled water.

Carbonyl iron [2] or other iron containing not less than 99.9% of the main substance.

Solution mass of iron concentration of 0.01 g/cmis prepared as follows: a sample of iron weighing 10,000 g is placed in a beaker with a capacity of 600 cm, flow 20−25 cm150 to 200 cmof nitric acid, diluted 1:1, dissolved by heating, cooled, transferred into a measuring flask with volume capacity of 1000 cmand adjusted to the mark with distilled water.

To prepare the solution of iron is allowed to use other substances, providing a set value of the reference experience.

Potassium permanganate according to GOST 20490, solution mass concentration of the potassium permanganate 0.01 g/cm.

Potassium iodide according to GOST 4232.

Solution the mass concentration of the potassium iodide 0.02 g/cmin hydrochloric acid is prepared as follows: a portion of iodide of potassium with a mass of 10.0 g is placed in a beaker with a capacity of 600 or 1000 cm, dissolved in 500 cmof hydrochloric acid, transferred to a separatory funnel with a capacity of 1000 cm, flow 25 cmof carbon tetrachloride, shake 2 min, the organic phase is discarded and repeat the extraction.

Wash solution is prepared as follows: mix 3 volume of solution of potassium iodide and 1 volume of distilled water.

Titanium sponge according to GOST 17746.

Solution the mass concentration of the titanium of 0.02 g/cmis prepared as follows: a portion of sponge titanium with a mass of 2,000 g was placed in a flask with a capacity of 250 cmunder reflux, poured 40 cmof sulphuric acid diluted 1:1, dissolved by heating, cooled, transferred to a volumetric flask with a capacity of 100 cmand adjusted to the mark with distilled water.

Carbon tetrachloride according to GOST 20288.

Arsenic [3].

Sodium orthoarsenic in [4].

Arsenic (III) oxide.

Solutions of known arsenic concentrations.

The solution And the mass concentration of arsenic 0.0001 g/cmof arsenic is prepared as follows: a portion of the arsenic mass 0,1000 g placed in a beaker with a capacity of 100 cm, flow 20 cmof nitric acid, diluted 1:1, first dissolve without heating, then heated until complete dissolution of sample arsenic, poured 20 cmof sulphuric acid diluted 1:1, evaporated to release vapors of sulfuric acid, cooled, poured 40 to 50 cmof distilled water, transferred to a measuring flask with volume capacity of 1000 cmand adjusted to the mark with distilled water.

The solution And the mass concentration of arsenic 0.0001 g/cmof oxide of arsenic (III) is prepared as follows: a portion of oxide of arsenic (III) mass 0,1320 g were placed in a glass with a capacity of 100 cm, flow 10 cmof sodium hydroxide solution, distilled water to volume of 40 cm, transferred into a measuring flask with volume capacity of 1000 cm, 40 cm pouredsulphuric acid, diluted 1:3, adjusted to the mark with distilled water.

The solution And the mass concentration of arsenic 0.0001 g/cmfrom orthoarsenate sodium is prepared as follows: a portion of orthoarsenate sodium weight 0,2560 g were placed in a glass with a capacity of 250 cm, is dissolved in 50 cmof distilled water, transferred to a measuring flask with volume capacity of 1000 cm, 40 cm pouredsulphuric acid, diluted 1:3 and adjusted to the mark with distilled water.

Solution B is the mass concentration of arsenic 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 sulfuric acid, diluted 1:15.

4.3 Preparation for analysis

To build a calibration curve in a volumetric flask with a capacity of 50 cmstand 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cmof a solution, pour distilled water to a volume of 30 cm, is added dropwise a solution of potassium permanganate until a stable pink color, 4 cmof the reaction mixture. Flasks with solutions were placed in a boiling water bath, maintained for 15 min, cooled, adjusted to the mark with distilled water and measure the absorption of the calibration solutions in accordance with 4.4.

The mass of arsenic in the calibration solutions is 0,000005; 0,000010; 0,000020; 0,000030; 0,000040 and 0,000050 G.

The light absorption values of the calibration solutions and corresponding mass of arsenic build the calibration graph, given the values of absorption of the calibration solution, prepared without the introduction of a solution containing arsenic.

4.4 analysis

A portion of the sample with a mass of 5,000 g (with mass fraction of arsenic not more than 0,0010%) or weighing 0,500 g (with mass fraction of arsenic of more than 0,0010%) were placed in a glass with a capacity of 400 or 500 cm, flow 50 to 60 cmor from 15 to 20 cmof nitric acid, diluted 1:1, is dissolved when heated, is evaporated to a volume of 10 to 15 cm, pour distilled water to a volume of 100 to 150 cm, 2.0 cmof a solution of iron, heated from 60 °C to 70 °C, poured from 7 to 10 cmof ammonia. Solution under stirring was transferred to a beaker with a capacity of 600 cm, which is pre-placed 1.5 g of ammonium chloride and 100 cmof ammonia. The Cup, which was held a dissolution, washed two or three times with ammonia, diluted 1:19. Solution and the precipitate is kept for 20−30 minutes in a warm place and filter the precipitate on a filter (red or white ribbon).

Dissolve the residue in 20 cmhot hydrochloric acid, diluted 1:1, collecting the filtrate in a beaker, which was conducted evaporation, the filter washed with 20 cmof hot distilled water.

Add dropwise a solution of titanium to a bleaching solution and optionally, 2−3 drops.

Transfer the solution into the separatory funnel with a capacity of 250 cm, poured from 80 to 90 cmof a solution of potassium iodide (molar concentration of hydrochloric acid in the separating funnel should be at least 9 mol/DM), 30 cmof carbon tetrachloride and shake the separatory funnel 2 min. the Organic phase is decanted into a separating funnel with a capacity of 100 cm, and the aqueous phase poured 15 cmof carbon tetrachloride and repeat the extraction. The organic phases are combined, and the aqueous phase discarded.

To the combined organic phase poured 20 cm ofwash solution, shake the funnel for 30 s. the Aqueous phase is discarded and the organic phase poured 15 cmof distilled water separatory funnel and shake for 2 min. the Organic phase was drained into another separatory funnel with a capacity of 100 cm, and the aqueous phase transferred to a volumetric flask with a capacity of 50 cm. Stripping with distilled water again, the organic phase discarded and the aqueous phase attached to the solution in a volumetric flask.

The flask is added dropwise a solution of potassium permanganate until a stable pink color and 4 cmof the reaction mixture, placed the flask with the solution in a boiling water bath, maintained for 15 min, cooled, adjusted to the mark with distilled water and measure the light absorption of the sample solution on the spectrophotometer at a wavelength of 610 nm or 840 or photoelectrocolorimeter in the wavelength range from 590 to 640 or 820 to 860 nm, using the solution comparison distilled water.

The value of the light absorption of the sample solution find the mass of arsenic in the calibration schedule.

4.5 Processing the analysis results

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

, (1)

where Mis the mass of arsenic in the sample solution, g;

Mis the mass of arsenic in solution in the reference experiment, g;

M — weight of sample, g.

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 1.


Table 1 — Requirements of control precision (limits of repeatability and reproducibility) and the increased control precision — the expanded uncertainty of the results of the analysis at a confidence probability P=0,95

Percentage

5 Atomic absorption method

5.1 Method of analysis

The method is based on measuring absorption at a wavelength of 193.7 nm resonance radiation by arsenic atoms generated by the electrothermal atomization of the sample solution.

5.2 measurement Means, 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 hollow cathode or electrodeless discharge lamp for excitation of spectral lines of arsenic.

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.

Sodium hydroxide according to GOST 4328.

Nickel powder according to GOST 9722 or standard sample of Nickel, for example [5], pre-installed (certified) mass fraction of arsenic not more than 0.0001%.

Cobalt GOST 123 or standard sample of cobalt, for example, [6], pre-installed (certified) mass fraction of arsenic not more than 0.0001%.

Arsenic [3].

Sodium orthoarsenic in [4].

Arsenic (III) oxide.

Solutions of known arsenic concentrations.

The solution And the mass concentration of arsenic 0.0001 g/cmof arsenic is prepared as follows: a portion of the arsenic mass 0,1000 g placed in a beaker with a capacity of 100 cm, flow 20 cmof nitric acid, diluted 1:1, first dissolve without heating, then heated until dissolved, transfer the solution into a measuring flask with volume capacity of 1000 cm, 50 cm pournitric acid, diluted 1:1, and adjusted to the mark with distilled water.

The solution And the mass concentration of arsenic 0.0001 g/cmof oxide of arsenic (III) is prepared as follows: a portion of oxide of arsenic (III) mass 0,1320 g were placed in a glass with a capacity of 100 cm, is dissolved in 10 cmof sodium hydroxide solution, poured distilled water to a volume of 40 cm, transfer the solution into a measuring flask with volume capacity of 1000 cm, 100 cm pournitric acid, diluted 1:1, cooled and adjusted to the mark with distilled water.

The solution And the mass concentration of arsenic 0.0001 g/cmfrom orthoarsenate sodium is prepared as follows: a portion of orthoarsenate sodium weight 0,2560 g were placed in a glass with a capacity of 250 cm, dissolve the salt in 50 cmof distilled water, transfer the solution into a measuring flask with volume capacity of 1000 cm, 50 cm pournitric acid, diluted 1:1, adjusted to the mark with distilled water.

Solution B is the mass concentration of arsenic 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 arsenic 0,000002 g/cmis prepared as follows: into a measuring flask with a capacity of 100 cm andstand 20 cmof solution B and bring to the mark with nitric acid, diluted 1:19.

5.3 Preparation for assay

5.3.1 To construct a calibration chart 1 in determining the mass fraction of arsenic not more than 0,0010% sample of Nickel powder or cobalt or of a standard sample of composition of Nickel or cobalt with a mass of 1,000 grams is placed in glasses 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 by heating in the amount of 15 to 20 cmof nitric acid, diluted 1:1, boiled for 2−3 min. When using 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 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 is transferred 0,5; 1,0; 2,0; 3,0; 4,0; 5,0 cmof solution B. the flask with the solution in the reference experiment, the solution containing the arsenic, not poured, adjusted to the mark with distilled water and measure the absorbance in accordance with 5.4.

The mass of arsenic in the calibration solutions is 0,000001; 0,000002; 0,000004; 0,000006; 0,000008; 0,000010 G.

5.3.2 For the construction of calibration curve 2 in determining the mass fraction of arsenic of more than 0,0010% in volumetric flasks with a capacity of 100 cmshift 10 cmof the solution in the reference experiment, prepared in accordance with 5.3.1, poured 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cmof solution V. one of the flasks with a solution of the reference experiment a solution containing arsenic, not poured, adjusted to the mark with nitric acid, diluted 1:19, and measure absorption in accordance with 5.4.

The mass of arsenic in the calibration solutions specified in 5.3.1.

5.4 analysis

A portion of the sample with a mass of 1,000 g was placed in a beaker with a capacity of 250 cm, flow 15 to 20 cmof nitric acid, diluted 1:1, is dissolved when heated, is evaporated to a volume of 5 to 7 cm, transferred to a volumetric flask with a capacity of 100 cm, cooled, adjusted to the mark with distilled water.

For the mass concentration of arsenic more than 0,0010% in a volumetric flask with a capacity of 100 cmstand aliquot part of the solution volume of 10 cmand was adjusted to the mark with nitric acid, diluted 1:19.

The absorbance of the sample solution and the calibration solutions at a wavelength of 193.7 nm, slit width is not more than 2.0 nm with the 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 to select the optimal amount of solution injected into the atomizer, from 0.010 to 0.050 cmor optimal time of the aerosol spraying of the solution 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 5.3.

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 2.


Table 2 — operating conditions of the atomizer

The values of absorption of the calibration solutions and corresponding mass of arsenic build the calibration graph.

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

5.5 Processing of analysis results

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

, (2)

where Mis the mass of arsenic in the sample solution, g;

K — dilution factor of sample solution;

M — weight of sample, g.

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

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* Valid on the territory of the Russian Federation.