GOST 6012-2011

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  ГОСТ 6012-2011

GOST 6012−2011 Nickel. Methods of chemical-atomic-emission spectral analysis

GOST 6012−2011

Group B59

INTERSTATE STANDARD

NICKEL

Methods of chemical-atomic-emission spectral analysis

Nickel. Methods of chemical-atomic-emission spectral analysis

ISS 77.040
AXTU 1732

Date of introduction 2013−01−01

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 the Interstate technical Committee for standardization MTK 501 Nickel

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

3 ACCEPTED by the Interstate Council for standardization, Metrology and certification (Protocol of 29 November 2011 No. 40)

The adoption voted:

4 by Order of the Federal Agency for technical regulation and Metrology dated 17 may 2012 N 70 St interstate standard GOST 6012−2011 introduced as a national standard of the Russian Federation from January 1, 2013

5 REPLACE GOST 6012−98


Information about introduction in action (termination) of this standard is published published monthly information index «National standards».

Information about the changes to this standard is published in the annually issued reference index «National standards», and the text changes and amendments — in monthly indexes published information «National standards». In case of revision or cancellation of this standard the appropriate information will be published in a monthly information index «National standards»

1 Scope

This standard specifies the methods of chemical-atomic-emission spectral analysis with a DC arc and inductively coupled plasma as a source of excitation spectrum for determination of mass fractions of elements in Nickel GOST 849, Nickel powder according to GOST 9722 and Nickel and Nickel alloys according to GOST 492 and GOST 19241.

2 Normative references

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

GOST 8.315−97 State system for ensuring the uniformity of measurements. Standard samples of composition and properties of substances and materials. The main provisions of the

GOST 12.0.004−90 System of standards of occupational safety. Organization of training safety. General provisions

GOST 12.1.004−91 System safety standards. Fire safety. General requirements

GOST 12.1.005−88 standards System of labor safety. General hygiene requirements for working zone air

GOST 12.1.007−76 System of standards of occupational safety. Harmful substances. Classification and General safety requirements

GOST 12.1.016−79 System of standards of occupational safety. The air of the working area. Requirements for measurement techniques of concentrations of harmful substances

GOST 12.1.019−79 System of standards of occupational safety. Electrical safety. General requirements and nomenclature of types of protection*
________________
* On the territory of the Russian Federation GOST R 12.1.019−2009.


GOST 12.1.030−81 System of standards of occupational safety. Electrical safety. Protective grounding, neutral earthing

GOST 12.2.007.0−75 System safety standards. Products electrical. General safety requirements

GOST 12.3.002−75 System safety standards. The process of production. General safety requirements

GOST 12.3.019−80 standards System of labor safety. Test and measurement electrical. General safety requirements

12.4.009 GOST-83 System of standards of occupational safety. Fire fighting equipment for protection of objects. Principal. The accommodation and service

GOST 12.4.021−75 System safety standards. System ventilation. General requirements

GOST 61−75 Reagents. The acetic acid. Specifications

GOST 83−79 Reagents. Sodium carbonate. Specifications

GOST 123−2008 Cobalt. Specifications

GOST 195−77 Reagents. Sodium sanitarily. Specifications

GOST 244−76 Sodium thiosulfate crystal. Specifications

GOST 492−2006 Nickel, Nickel alloys, and copper-Nickel, processed by pressure. Brand

GOST 804−93 primary Magnesium ingots. Specifications

GOST 849−2008 Nickel primary. Specifications

GOST 859−2001 Copper. Brand

GOST 860−75 Tin. Specifications

GOST 1089−82 Antimony. Specifications

GOST 1467−93 Cadmium. Specifications

GOST 2820−73 Strontium nitrate. Specifications

GOST 3118−77 Reagents. Hydrochloric acid. Specifications

GOST 3640−94 Zinc. Specifications

GOST 3778−98 Lead. Specifications

GOST 4160−74 Reagents. Potassium bromide. Specifications

GOST 4198−75 Reagents. Potassium phosphate odnosemjannyj. Specifications

GOST 4204−77 Reagents. Sulphuric acid. Specifications

GOST 4212−76 Reagents. Methods of preparation of solutions for colorimetric and nephelometric analysis

GOST 4233−77 Reagents. Sodium chloride. Specifications

GOST 4461−77 Reagents. Nitric acid. Specifications

GOST 4530−76 Reagents. Calcium carbonate. Specifications

GOST 5494−95 aluminum Dust. Specifications

GOST 5817−77 Reagents. Acid wine. Specifications

GOST 5905−2004 (ISO 10387:1994) metal Chrome. Technical requirements and delivery conditions

GOST 6008−90 metallic Manganese and nitrated manganese. Specifications

GOST 6709−72 distilled Water. Specifications

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

GOST 8655−75 red Phosphorus technical. Specifications

GOST 9147−80 Glassware and equipment lab porcelain. Specifications

GOST 9428−73 Reagents. Silicon (IV) oxide. Specifications

GOST 9722−97 Nickel Powder. Specifications

GOST 9849−86 iron Powder. Specifications

GOST 10157−79 Argon gaseous and liquid. Specifications

GOST 10298−79 Selenium technical. Specifications

GOST 10484−78 Reagents. Acid fluoride-hydrogen. Specifications

GOST 10928−90 Bismuth. Specifications

GOST 11069−2001 primary Aluminium. Brand

GOST 11125−84 nitric Acid of high purity. Specifications

GOST 12797−77 Gallium technical. Specifications

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 17299−78 ethyl Alcohol technical. Specifications

GOST 17614−80 Tellurium technical. Specifications

GOST 18300−87 ethyl rectified technical. Specifications

GOST 18337−95 Thallium. Specifications

GOST 19241−80 Nickel and alloyed Nickel alloys treated under pressure. Brand

GOST 19627−74 Hydroquinone (paradoxians). Specifications

GOST 19908−90 Crucibles, bowls, beakers, flasks, funnels, test tubes and caps made of transparent quartz glass. General specifications

GOST 22860−93 Cadmium high purity. Specifications

GOST 22861−93 Lead of high purity. Specifications

GOST 23148−98 (ISO 3954−77) Powders used in powder metallurgy. Sampling

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. Testing»: from 01.01.2010 — in part newly developed and modernized scales; from 01.01.2013 — weights, designed to 01.01.2010.


GOST 24231−80 non-ferrous metals and alloys. General requirements to selection and preparation of samples for chemical analysis

GOST 25086−2011 non-ferrous metals and their alloys. General requirements for methods of analysis*
________________
* In the Russian Federation control the accuracy of the analysis carried out in accordance with GOST R ISO 5725−1-2002 and GOST R ISO 5725−2-2002, GOST R ISO 5725−4-2002 and GOST R ISO 5725−6-2002.


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

GOST 25664−83 Metol (4-methylaminophenol sulfate). Specifications

ST SEV 543−77 Number. Record rules and rounding

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.

3 General requirements

3.1 General requirements for methods of analysis should correspond to GOST 25086.

3.2 Selection and preparation of samples of Nickel and Nickel alloys is carried out according to GOST and GOST 849 24231, Nickel powder according to GOST 23148 and GOST 9722.

3.3 To establish the calibration according to recommended to use at least four standard samples according to GOST 8.315 composition of Nickel or at least four solutions of known mass concentration of elements.

3.4 When the analysis is carried out two parallel definitions.

3.5 the value of the result of the analysis should be terminated with a figure the same category as the value of expanded uncertainty guaranteed in the application of the methods of analysis prescribed by this standard.

In the preparation of quality document production on the basis of the results of the analysis allowed the measurement result of the chemical composition to represent a number with the same number of significant figures as in the tables of chemical composition to GOST 849, GOST 9722, GOST 492 and GOST 19241.

3.6 Rules for rounding of numbers shall conform to the requirements of ST CMEA 543.

4 safety Requirements

4.1 carry out All work on the appliances and electrical installations, relevant regulations for electrical [1] and requirements of GOST 12.2.007.0.

4.2 When the equipment and installations required to comply with the requirements of GOST 12.3.019 and rules [2], [3].

4.3 All equipment and installations should be equipped with devices for grounding in accordance with the requirements of GOST 12.2.007.0 and GOST 12.1.030. Grounding must conform to the rules [1].

4.4 During the execution of works are used and are formed of substances which have a deleterious effect on the human body: Nickel powder, aerosols of metal oxides, carbonaceous dust, oxides of nitrogen and carbon, vapors of hydrochloric and nitric acids and ethyl alcohol. Storage and use of hazardous substances and materials shall comply with the requirements, regulated in the normative documents for these substances and materials.

4.5 Analysis of Nickel held in a room equipped with General ventilation system according to GOST 12.4.021.

4.6 To prevent contact with the air, oxides of carbon, nitrogen and aerosols of metal oxides in quantities exceeding the maximum allowable concentration according to GOST 12.1.005, as well as protection from UV radiation of each excitation source must be placed inside devices equipped with local exhaust ventilation and protective screen according to GOST 12.1.019.

4.7 grinding Machine carbon electrodes should have a suction device to prevent the ingress of coal dust in the air of working zone in quantities exceeding the maximum allowable.

4.8 Control of content of harmful substances in the air of working zone should be carried out in accordance with the requirements of GOST 12.1.005, GOST 12.1.007 and GOST 12.1.016.

4.9 Disposal, deactivation and destruction of hazardous wastes from tests of Nickel should be carried out in accordance with the sanitary regulations [4].

4.10 the Organization of training of the working personnel to the requirements of labour safety — according to GOST 12.0.004.

4.11 Requirements for professional selection and testing of knowledge of employees — according to GOST 12.3.002.

4.12 the premises of the laboratory must comply with the fire safety requirements according to GOST 12.1.004 and have a extinguishing media in accordance with GOST 12.4.009.

4.13 laboratory Personnel must be provided with premises according to the sanitary norms and rules [5] the group IIIA of the production processes.

4.14 laboratory Personnel must be provided with overalls, special footwear and other means of individual protection according to the norms [6].

5 a Method of chemical-atomic-emission spectral analysis with a DC arc as excitation source spectrum

5.1 measurement Method

The ranges defined by the mass fraction of elements, %:

— aluminium — 0,0002−0,1;

boron 0,0001−0,001;

— bismuth — 0,00001−0,01;

— gallium — 0,00003−0,0003;

— iron — 0,001−1,0;

— cadmium — 0,00005−0,01;

— calcium 0,0005−0,05;

— cobalt of 0.0003 to 1.0;

— silicon — 0,0003−0,2;

— magnesium — 0,0001−0,2;

— manganese — 0,00005−0,2;

— copper — 0,00005−1,0;

— arsenic — 0,0001−0,01;

— tin — 0,00003−0,01;

— lead — of 0.00005 and 0.01;

— selenium — 0,0001−0,01;

— silver — 0,00001−0,002;

— strontium — 0,0001−0,001;

— antimony — 0,0001−0,01;

— thallium — 0,00002−0,003;

— Tantal — 0,0001−0,005;

— tellurium — 0,00005−0,003;

— phosphorus of 0.0001−0,005;

— chrome — 0,0001−0,001;

— zinc 0,0001−0,01.

The method is based on the excitation spectrum of the element in the arc of DC, with the subsequent registration of the radiation of spectral lines photographic, or photoelectric means. The analysis uses the dependence of the intensities of spectral lines of the elements from their mass fraction in the sample. The sample is pre-transferred to the oxide form.

Items and options that apply only to photographic or photoelectric method of registration of the spectrum, indicated in the text of FG and FE, respectively.

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

A multichannel photoelectric spectrometer type IFS-8 (FE) or a type spectrograph STE-1 (FG), or any other spectrometer or spectrograph for ultraviolet region of the spectrum with an inverse linear dispersion of 0.6 nm/mm.

Power source DC arc type, UGE-4, or any other, providing a voltage up to 400 V and currents up to 20 A.

Microphotometer geregistreerde of any type (FG).

Laboratory scales special or high precision of any type according to GOST 24104.

Libra technical of any type that provides the measurement of weight up to 500 g.

Standard samples of composition of the Nickel produced in accordance with Appendix A or other method approved in the prescribed manner.

Muffle furnace of any type with thermostat providing temperatures up to 850 °C.

Press which provides sufficient force for tabletting the crushed metal oxides.

Mold alloy steel punch with a diameter of from 4 to 8 mm.

Varicellae bowls or crucibles made of quartz glass according to GOST 19908 or bowls, crucibles and cups of glassy carbon according to [7] for dissolution of samples, evaporation of the solution and calcination of a mixture of salts. Allowed for dissolution and evaporation apply flask and glasses from chemically and thermally resistant glass according to GOST 25336. Allowed for the analysis of samples of Nickel grades N-3 and N-4, electrolytic Nickel powder and Nickel alloys to use bowls and crucibles made of porcelain to GOST 9147.

The machine with a set of shaped cutters for sharpening electrodes.

Graphite electrodes with a diameter of 6 mm as an upper electrode and a diameter of from 6 to 15 mm as electrodes-stand by [8], [9].

Wool.

Cups for weighing according to GOST 25336 or porcelain pumps type LZ GOST 9147.

Caps glass or plastic to protect from contamination prepared for analysis of tablets of samples, standard samples and sharpened electrodes.

A pair of tweezers.

Mortar with pestle, agate or Jasper.

Photographic plates spectrographic contrast (FG) [10].

Distilled water according to GOST 6709, further purified by distillation or otherwise.

Nitric acid is the OS.h. according to GOST 11125 or qualification H. h or h. d. a. according to GOST 4461, further purified by distillation or otherwise, and diluted 1:1.

Hydrochloric acid according to GOST 3118, diluted 1:10.

Sodium chloride according to GOST 4233, H. h

The technical rectified ethyl alcohol according to GOST 18300 or technical ethyl alcohol according to GOST 17299, further purified by distillation or otherwise.

Sodium salitsilovaya, solution in ethyl alcohol mass concentration of 60 g/DM(FG).

The developer consisting of two solutions (FG).

Solution 1:

— metol (parameterindependent) according to GOST 25664 — 2.5 g;

— hydroquinone (paradoxians) according to GOST 19627 — 12 g;

— sanitarily anhydrous sodium GOST 195 — 55 g;

— distilled water according to GOST 6709 — 1 DM.

Solution 2:

the anhydrous sodium carbonate according to GOST 83 — 42 g;

— potassium bromide according to GOST 4160 — 7 g;

— distilled water according to GOST 6709 — 1 DM.

Before the manifestation of the solutions 1 and 2 mixed in a volume ratio of 1:1. Allowed to apply contrast working developer of a different composition.

Fixing solution (FG):

— sodium thiosulfate crystal according to GOST 244 — 400 g;

— sanitarily anhydrous sodium GOST 195 — 25 g;

— acetic acid according to GOST 61 — 8 cm;

— distilled water according to GOST 6709 — 1 DM.

5.3 Preparation for assay

A portion of the sample weighing 5 to 10 g placed in a Cup made of quartz glass or another utensil to dissolve. To remove accidental contamination of samples with iron is recommended in the analysis of Nickel cathode marks N-0, N-1au, N-1U N-1 sample pre-processing 30 to 50 cmof hydrochloric acid, diluted 1:10, stirring for 1 min. Acid is drained by decantation and rinsed with the sample two or three times with water portions of 50 cmby decantation.

To the sample flow portions from 3 to 5 cmof nitric acid diluted 1:1, until complete dissolution of the sample when heated. If you want to determine the mass fraction of selenium in dilute nitric acid is replaced by concentrated.

The solution was evaporated in a bowl of quartz glass or other utensils to remove the excess of nitric acid to the receipt of dry salts, to prevent any decomposition of the nitrate salts to oxides (the appearance of dark inclusions in the sample material). A bowl of dry salt is placed in a muffle furnace, heated to a temperature of (825±25) °C and maintained at this temperature for 15 to 20 min. the resulting oxides are cooled, then comminuted to obtain a powder in a mortar or other method eliminating contamination of sample material.

From powder taken three sample weighing 0.200 to 1,000 g each, depending on conditions analysis and a mass fraction of detectable elements and their tableted using a press and molds.

When determining the mass fraction of gallium, thallium, and zinc to reduce the intensity of the continuous background, if necessary, the imposition of emissions from several tablets on the same place of photographic plates allowed to use the buffer substance is sodium chloride. For this purpose a portion of the sample and the standard sample mixed with sodium chloride in a weight ratio of 1:100.

Mold clean residue from the sample with cotton wool soaked with ethyl alcohol. Consumption of ethanol is 10 cmon the sample.

Standard samples of composition of Nickel in the form of metal prepared for analysis in the same way as the sample. Standard samples of composition of Nickel in the form of oxides prepared for analysis, not by swiping them through a stage of dissolution in nitric acid.

5.4 analysis

Preparing the spectrometer to the measurements carried out in accordance with the manual for operation and maintenance of the spectrometer (FE).

Recommended wavelengths of the analytical lines and the ranges of detectable concentrations of elements are given in table 1.


Table 1 — Recommended wavelengths of the analytical lines and the ranges of detectable concentrations of the elements

Allowed to use other analytical lines, if they provide a determination of mass fraction of elements in the required range of uncertainty, do not exceed this standard.

Pill sample or standard sample is placed on the electrode stand. The upper electrode should be sharpened to a truncated cone.

The electrode pre-calcined in the arc of DC current for 10 to 20 s at a current of from 6 to 10 And including them as anode in the arc. The electrodes of the OS.h. not allowed to be heated up.

The shape and dimensions of the electrodes and their location during the analytical exposure is shown in figure 1.

Figure 1. The shape and dimensions of the electrodes and their location during the analytical exposition

and — before exposure; b — at the anode the polarity of the sample; in — at the cathode the polarity of the sample

Figure 1

Spectrograms photographed through a three-stage attenuator. When working in a narrow range of detectable concentrations of the elements of the photographing can be performed without the attenuator (FG).

The electrode stand is placed on it a tablet of sample or standard sample is composed of the anode of the arc. The spectrum starts only after the transition of the anode spot of the arc on the melt sample. Transition speed up shutdown current after a few seconds of arc and re-enabling until the melt has not yet had time to cool down. Originally established arc gap adjusted periodically throughout the exposure on a zoomed image of the arc on the screen of the objective lens of the lighting system or with a special short throw projection lens. The spectrum carried out under the following conditions: the width of the entrance slit of the spectral device is from 0.010 to 0.015 mm, the illumination slits being a condenser, the aperture height in the middle of the condenser lens is 5 mm, current intensity — 5 to 10 A, exposure — from 40 to 60, weight pills is from 0.200 to 1,000 g. the measurements obtained in the first stage, determine the volatile elements bismuth, cadmium, arsenic, tin, lead, selenium, silver, antimony, thallium, tellurium, zinc, phosphorus and gallium.

Formed during the first stage, the Wren is placed on sweetalicious the stand and include it as the cathode of the arc. The spectrum begins after the transition of the cathode spot of the arc from the cradle to the molten portion of the bead and hold it under the following conditions: the width of the entrance slit is from 0.010 to 0.015 mm, the illumination slits being a condenser, the aperture height in the middle of the condenser lens — 3 mm, current — from 3 to 6, exposure — 20 to 40 C. the measurements obtained in the second stage, determine the semi-elements — aluminum, iron, calcium, cobalt, silicon, magnesium, manganese, copper, tantalum, chromium, boron and strontium.

Allowed to carry out the second stage without removing the bead from the base at the end of the first stage, automatically changing the polarity of the electrodes and the current arc (FE).

When determining the mass fraction of selenium and the need to reduce detection limits of volatile elements analytical lines with wavelengths less than 230 nm, the additional third stage. Photographic plates are treated in a solution of sodium salicylanilide for 60 s and dried. Pill sample or standard sample is composed of the anode of the arc. Conditions of registration of the spectrum: the slit width of the spectrograph is from 0.018 to 0.020 mm, the illumination slits being a condenser, the aperture height in the middle of the condenser lens is 5 mm, the current strength is between 18 to 20 And exposure — from 45 to 60 s, electrode stand with a diameter of 15 mm with a recess on the end of the 1.5 mm, weight-pills — from 0,700 to 1,000 g (FG).

Photographic plates show within 4 to 6 minutes at a temperature of from 18 °C to 20 °C, fixed, washed and dried (CF).

Optimization of conditions for the analysis of a specific type or brand of products is carried out by selection of the values of variables parameters (mass of tablets, arc current, exposure, width of the entrance slit of the spectral device), selection of optimum analytical lines, of the type of photographic plates, the shape of the upper electrode, etc.

5.5 Processing and presentation of results of analysis

In the spectra of samples and standard samples to measure the intensity of the analytical lines of the elements and lines of comparison of Nickel. Permitted instead of the intensity of the comparison lines to use the undecomposed light intensity (PE) and the minimum value of the optical density of the background measured near the analytical line (FG).

While photographic registration of the spectrum in the spectrograms of the samples and the standard sample and measure the blackening of analytical lines of the determined elements and lines comparison, choosing the level of attenuation with optimum values of pucherani. The results of the three measurements of intensity values calculates the difference pucherani and their arithmetic mean values for each standard sample and each individual sample determination. Before averaging, it is recommended to check the suitability of the measurement results in accordance with Annex B.

According to calculated values for the standard sample and the corresponding values of the mass fraction of detectable elements to build calibration graphs in the coordinate: .

Values for samples find the mass fraction of detectable elements on the respective calibration graphs.

By the photoelectric registration of spectrum according to the obtained results of the three measurements of intensity of analytical lines of elements determined by calculating the arithmetic mean values for each standard sample and each individual sample determination. Before calculating the arithmetic mean value is recommended to check the suitability of the measurement results in accordance with Annex B. the calculated values for the standard samples and their corresponding values of mass fraction of detectable elements to build calibration graphs in the coordinate: or .

When working on the spectrometer with a computer the values of the mass fraction of elements in standard samples and their corresponding arithmetic mean values of measurements of the intensity of the analytical lines of the determined elements is introduced into a computer system that generates the equation of the calibration dependence.

Values or samples to find the mass fraction of detectable elements on the respective calibration graphs.

The test of admissibility analysis results in terms of repeatability is carried out by comparing the discrepancies in the results of two parallel measurements with a limit of repeatability in table 2. The results of the parallel definitions recognize acceptable and it calculates the arithmetic mean value of results of parallel measurements when the condition , for a confidence level of 95%, where  — standard deviation results of parallel measurements obtained in conditions of repeatability.

When the divergence of the results of parallel measurements more than the permissible limit of the repeatability analysis is repeated, earning another two results of parallel measurements. If the range () of the results of the four definitions of equal or less value of the critical range for probability level 95% at 4, the final result should be recorded, the arithmetic mean value of the results of the four definitions.

The critical range for four parallel measurements is calculated by the formula where  — the standard deviation results of parallel measurements obtained in conditions of repeatability.

If the range of four measurements greater than the critical range for 4, then proceed as follows: to investigate the cause of exceedance of critical range and repeat the analysis on samples obtained by repeated sampling. Allowed as a final result to record the median of the results of the four definitions

. (1)

The result of the analysis in the papers for his performance, are or when , where the enrolment rate for recommendations [11]. In case the results of the analysis indicate a link to a document that establishes the value of the expanded uncertainty (error bound) test results.

Values of expanded uncertainty of results of the analysis are shown in table 2.

5.6 Control of accuracy of analysis

The control accuracy of the analysis carried out in accordance with GOST 25086 at least once a quarter. The frequency of operational monitoring of the accuracy of analysis and control procedures stability analysis results reglamentary in the documents of the laboratory. As standard for the control of accuracy using the values of extended uncertainty analysis method in [11], are shown in table 2.

Regulations control precision — the repeatability limit and the reproducibility limit of the two results and the standard of the accuracy control — the expanded uncertainty given in table 2.


Table 2 — Requirements of control precision (repeatability and reproducibility) and the ratio control accuracy (expanded uncertainty) at a confidence probability of 0.95

Percentage

For intermediate values of the mass fraction of elements, calculate values , and is carried out by linear interpolation.

6 a Method of chemical-atomic-emission spectral analysis with inductively coupled plasma as the excitation source spectrum

6.1 measurement Method

The ranges defined by the mass fraction of elements, %:

aluminum of 0.0005−0.3;the

— iron — 0,001−1,0;

cadmium of 0.0002−0,005;

— cobalt — 0,0005−1,0;

— silicon 0,001−0,3;

— magnesium — 0,0005−0,01;

— manganese is from 0.0002−0.3 mm;

— copper — 0,0005−0,3;

— selenium is 0.0001−0,005;

— strontium — 0,0001−0,001;

— Tantal — 0,0001−0,001;

— phosphorus 0,001−0,01;

— chrome — 0,0001−0,001;

— zinc — 0,0003−0,01.

The method is based on the excitation spectrum of an element inductively coupled plasma with the subsequent registration of the spectral emission lines of the elements of the PV method. The analysis uses the dependence of the intensities of spectral lines of the elements from their mass fraction in the sample. The sample is dissolved in a mixture of hydrochloric and nitric acids.

6.2 measurement Means, auxiliary devices, materials, reagents, solutions

The automated spectrometer (or monochromator polychromator) atomic emission with inductively coupled plasma as the excitation source spectrum with all peripherals.

Laboratory scales special or high precision of any type according to GOST 24104.

Argon according to GOST 10157.

Distilled water according to GOST 6709, further purified by distillation or otherwise.

Nitric acid is the OS.h. according to GOST 11125 or qualification H. h according to GOST 4461, or qualifications h. d. a. according to GOST 4461, further purified by distillation or otherwise, and diluted 1:1 and 1:10.

Tartaric acid according to GOST 5817, solution mass concentration of 150 g/DM.

Hydrochloric acid OS.h. according to GOST 14261.

A mixture of acids: 800 cmof water was added 300 cmof hydrochloric acid and 100 cmof nitric acid.

Acid fluoride-hydrogen GOST 10484.

Aluminium GOST 11069 or aluminum powder according to GOST 5494.

Cadmium GOST 1467 or GOST 22860.

Potassium phosphate according to GOST 4198, dried at a temperature of (105±2) °C for 1 h.

Cobalt GOST 123.

Magnesium primary GOST 804.

Manganese GOST 6008.

Copper according to the GOST 859.

Sodium silicate 9-water [12].

Sodium carbonate according to GOST 83, solution of the mass concentration of 200 g/DM.

Iron powder brand MLB-1 according to GOST 9849 or carbonyl iron OS.h. in [13].

Nickel powder carbonyl group «U» or «0» according to GOST 9722 or Nickel stamps N-0 GOST 849 with established mass proportions of elements.

Selenium technical GOST 10298.

Strontium nitrate according to GOST 2820.

Foil tantalum [14].

Chrome metal according to GOST 5905.

Zinc GOST 3640.

A solution of Nickel mass concentration of 200 g/DM: a suspension of Nickel powder or Nickel with a mass of 100.00 g were placed in a glass with a capacity of 1000 cm, add 50 cmof water and portions of 5 to 10 cmpour 400 cmof nitric acid. The solution was evaporated to a volume of from 250 to 300 cm, cooled, transferred to a volumetric flask with a capacity of 500 cmand topped to the mark with water. When using the Nickel powder in the solution was filtered through a filter medium density, pre-washed with nitric acid, diluted 1:10.

Solution of iron and cobalt mass concentration of 1 g/DM: hanging iron weight 0,5000 g was dissolved with heating in 30acid mixtures, boiled for 5 to 10 minutes, cooled and transferred to volumetric flask with a capacity of 500 cm. A portion of the cobalt weight 0,5000 g was dissolved with heating in 25 cmof nitric acid, diluted 1:1, the solution was cooled, transferred to the same volumetric flask and topped to the mark with water.

Solution of manganese and copper mass concentration of 1 g/DMand of magnesium mass concentration of 0.1 g/DM: sample of manganese and copper for weight 0,5000 g of magnesium with a mass 0,1000 g separately dissolved by heating in 25 cmof nitric acid, diluted 1:1, boiled for 5 to 10 minutes, cooled, each solution was transferred to volumetric flasks with a capacity of 100 cmand then filled to the mark with water. In a volumetric flask with a capacity of 100 cmis taken at 20 cmobtained solutions of manganese and copper, and 10 cmof a solution of magnesium and topped to the mark with water.

A solution of aluminium mass concentration of 1 g/DM: a portion of the aluminum or aluminum powder weighing 0,4000 g was dissolved with heating in 25 cmof hydrochloric acid diluted 1:1, transferred into a volumetric flask with a capacity of 100 cmand then filled to the mark with water. In a volumetric flask with a capacity of 100 cmselect the 25 cmof this solution and topped up to the mark with water.

The solution of cadmium and zinc mass concentration 0.02 g/land phosphorus mass concentration of 0.04 g/DM: sample of cadmium and zinc by mass 0,1000 g separately dissolved by heating in 25 cmof nitric acid, diluted 1:1, cooled, each solution was transferred to volumetric flasks with a capacity of 500 cmand topped to the mark with water. Weighed potassium phosphate mass 0,4393 g dissolved in water, the solution was transferred to volumetric flask with a capacity of 500 cmand topped to the mark with water. In a volumetric flask with a capacity of 100 cmtaken at 10 cmthe obtained solutions of cadmium and zinc, and 20 cmof a solution of phosphorus and topped to the mark with water.

A solution of a silicon mass concentration of 0.5 g/DM: suspension of silicate of sodium with a mass 2,5297 g dissolved in 50 cmof sodium carbonate solution, the solution was transferred to volumetric flask with a capacity of 500 cmand topped to the mark with water.

Selenium solution, strontium and chromium mass concentration of 0.04 g/DM: a sample selenium of high purity by the mass of 0.2000 g was dissolved in nitric acid, the solution transferred to a flask with a capacity of 500 cmand topped to the mark with water. A portion of nitrate of strontium with a mass 0,2410 g dissolved in water containing 0.5 cmof nitric acid, the solution transferred to a volumetric flask with a capacity of 250 cm, and topped to the mark with water. A sample of chromium weighing of 0.2000 g was dissolved in hydrochloric acid, diluted 1:1, and the solution transferred to a flask with a capacity of 500 cmand topped to the mark with water. In a volumetric flask with a capacity of 100 cmis taken as 10 cmof solutions of selenium, strontium and chromium and topped to the mark with water.

A solution of tantalum mass concentration of 0.04 g/DM: a sample of tantalum metal mass 0,1000 g dissolved in platinum or Teflon Cup 5 cmhydrofluoric acid, dropwise adding nitric acid until complete dissolution of the sample. The solution is heated with 10 cmof nitric acid to remove excess of fluoride ion, cooled and diluted to a volume of 250 cmwith a solution of tartaric acid mass concentration of 150 g/DM. In a volumetric flask with a capacity of 100 cmis taken 10 cmof the resulting solution of tantalum and topped to the mark with water.

For the preparation of solutions of known mass concentrations of the elements use oxides or salts of stable composition, as well as state standard samples of solutions of metals.

Solutions of known concentrations of the elements stored in a plastic container. The conditions of storage and use of the solutions — in accordance with GOST 4212.

6.3 Preparation for analysis

6.3.1 Preparation of calibration mixtures

For the preparation of the calibration solutions 1−11, the recommended composition of which is given in table 3 in volumetric flasks with a capacity of 100 cmselect the calculated volumes of solutions with known concentrations of elements and topped to the mark with water. If necessary, make amendments to the mass fraction of element in carbonyl Nickel powder or Nickel, is used for preparation of a solution of Nickel. The calibration solutions are stored in a container made of polyethylene and is used for no more than three months.


Table 3 — Composition of the calibration mixtures

In milligrams per cubic decimeter

Mass concentration of Nickel in the calibration solutions 1 to 5 is 50 g/DM, in the calibration solutions 6−11−10 g/DM.

6.3.2 Preparation of solutions samples

A portion of the sample with a mass of 5,000 grams are placed in a beaker with a capacity of 250 or 400 cm, dissolved in 100 cmof the mixture of acids, adding the mixture of portions from 5 to 10 cm, the solution was evaporated to a volume of 25 to 30 cm, transferred into a volumetric flask with a capacity of 100 cmand then filled to the mark with water. The initial a sample solution is used for the determination of cadmium, zinc, phosphorus, selenium, strontium, tantalum and chromium.

In a volumetric flask with a capacity of 100 cmselect 20 cmof the primary sample solution and topped up to the mark with water. The diluted sample solution used for determination of cobalt, iron, copper, manganese, silicon, aluminum and magnesium.

6.4 analysis

Preparing the spectrometer to the measurements carried out in accordance with the instruction manual and maintenance spectrometer. The parameters of the spectrometer and the flow rate of argon is set within the range for maximum sensitivity to determine the mass fractions of elements.

Recommended wavelengths of the analytical lines and the ranges of detectable concentrations are given in table 4.


Table 4 — Recommended wavelengths of the analytical lines and the ranges of detectable concentrations of the elements

Allowed to use other analytical lines, if they provide a determination of mass fraction of elements in the required range of uncertainty, do not exceed this standard.

When working at the monochromator position check of the analytical lines, using the calibration solution of 5 or 10.

The calibration dependence for cadmium, zinc, phosphorus, selenium, strontium, tantalum and chromium find using the calibration solutions 1 to 5, and cobalt, iron, manganese, copper, magnesium, aluminum and silicon — calibration solutions 6−11.

For each calibration solution perform at least five parallel measurements of the intensities of the analytical lines of the determined elements. By calculating the arithmetic mean of the intensity values and corresponding mass concentrations of the elements determined the parameters of the calibration graphs, which are introduced into the computer memory at the stage of creating analytical programs.

Before the beginning of measurements and after every two hours of operation of the device adjust the calibration graphs for the two calibration solutions of 2 and 5 or 7 and 11.

For each of the sample solution and perform three parallel measurements of the intensity of analytical lines of the determined elements.

6.5 Processing and presentation of results

The mass fraction of detectable elements in the sample and their arithmetic mean values read from the screen or the tape printing device.

Records of the mass of sample dilution solutions of the sample and other variables is carried out automatically at the stage of introduction of analytical program in the computer.

The test of admissibility analysis results in terms of repeatability is carried out by comparing the discrepancies in the results of two parallel measurements with a limit of repeatability are given in table 5. The results of the parallel definitions recognize acceptable and it calculates the arithmetic mean value of results of parallel measurements when the condition , for a confidence level of 95%, where  — standard deviation results of parallel measurements obtained in conditions of repeatability.

When the divergence of the results of two parallel measurements more than the permissible limit of the repeatability analysis is repeated, earning another two results of parallel measurements. If the range () of the results of the four definitions of equal or less value of the critical range for probability level 95% at 4, the final result should be recorded, the arithmetic mean value of the results of the four definitions.

The critical range for four parallel measurements is calculated by the formula where  — the standard deviation results of parallel measurements obtained in conditions of repeatability.

If the range of four measurements greater than the critical range for 4, then proceed as follows: to investigate the cause of exceedance of critical range and repeat the analysis on samples obtained by repeated sampling. Allowed as a final result to record the median of the results of the four definitions

. (2)

The result of the analysis in the documents providing for its use, are or in . In case the results of the analysis indicate a link to a document that establishes the value of the expanded uncertainty (error bound) test results.

Values of expanded uncertainty of results of the analysis are shown in table 5.

6.6 accuracy Control analysis

The control accuracy of the analysis carried out in accordance with GOST 25086 at least once a quarter. The frequency of operational monitoring of the accuracy of analysis and control procedures stability analysis results reglamentary in the documents of the laboratory. As standard for the control of accuracy using the values of extended uncertainty analysis method in [11], are given in table 5.

Regulations control precision — the repeatability limit and the reproducibility limit of the two results and the standard of the accuracy control — the expanded uncertainty given in table 5.


Table 5 — Requirements of control precision (repeatability and reproducibility) and the ratio control accuracy (expanded uncertainty) at a confidence probability of 0.95

Percentage

For intermediate values of the mass fraction of elements, calculate values , and is carried out by linear interpolation.

Annex a (recommended). The method of preparation of standard samples for calibration

Appendix A
(recommended)

Standard samples for the calibration represent the crushed Nickel oxide with additives introduced the identified elements. The composition of the standard samples to develop a given mass fraction of elements in the analyzed products. Metrological characteristics of standard samples is set in accordance with the requirements of GOST 8.315. Standard samples can be used as samples for calibration when the ratio of the error of the certified values of standard samples and estimation methods (method) of measurements-not more than 1:3.

A. 1 measurement Means, auxiliary devices, materials, reagents, solutions

Laboratory scales special or high precision of any type according to GOST 24104.

Muffle furnace of any type with thermostat providing temperatures up to 850 °C.

Bowl varicellae quartz glass according to GOST 19908 or glassy carbon [7].

Mortar with pestle, agate or Jasper.

Distilled water according to GOST 6709, further purified by distillation or otherwise.

Nitric acid is the OS.h. according to GOST 11125 or skill hç and h. d. a. according to GOST 4461, further purified by distillation or otherwise, and diluted 1:1 and 1:2.

Sulfuric acid according to GOST 4204, diluted 1:2.

Tartaric acid according to GOST 5817.

Hydrochloric acid according to GOST 3118, diluted 1:1.

The technical rectified ethyl alcohol according to GOST 18300 or technical ethyl alcohol according to GOST 17299, further purified by distillation or otherwise.

Boron [15].

Bismuth GOST 10928.

Gallium GOST 12797.

Cadmium GOST 1467 or GOST 22860.

Calcium carbonate according to GOST 4530.

Acid fluoride-hydrogen GOST 10484.

Cobalt GOST 123.

Silicon (IV) oxide according to GOST 9428, crushed and sifted through a sieve with cell size 0,074 mm, or tetraethyl ester of silicic acid solution in ethyl alcohol.

Magnesium primary GOST 804.

Manganese GOST 6008.

Copper cathode according to the GOST 859.

Arsenic [16].

Aluminum powder according to GOST 5494.

Iron powder brand MLB-1 according to GOST 9849 or carbonyl iron OS.h. in [13].

Nickel powder carbonyl group «U» or «0» according to GOST 9722 or Nickel stamps N-0 GOST 849 with established mass proportions of the identified elements.

Tin GOST 860 or powder tin.

Lead at 3778 or GOST GOST 22861.

Selenium GOST 10298.

Silver GOST 6836.

Strontium GOST 2820.

Antimony GOST 1089.

Thallium GOST 18337.

Foil tantalum [14].

Tellurium GOST 17614.

Red phosphorus according to GOST 8655 or potassium phosphate according to GOST 4198, dried at a temperature of (105±2) °C for 1 h.

Chrome according to GOST 5905.

Zinc GOST 3640.

For the preparation of solutions of the input elements use oxides or nitrate salt of stable composition, as well as state standard samples of solutions of metals.

A. 2 Fabrication of standard samples

To prepare the solution framework of the standard samples a sample of Nickel powder or Nickel estimated mass is dissolved by heating in nitric acid, diluted 1:1.

Sample the calculated masses of iron, cobalt, copper, magnesium, manganese, aluminum powder, zinc, lead, bismuth, cadmium, silver, thallium, phosphorus, gallium, and calcium carbonate is dissolved by heating in nitric acid, diluted 1:1. Antimony is dissolved in the presence of tartaric acid at a weight ratio of antimony and tartaric acid 1:5. Boron, arsenic, selenium and tellurium is dissolved in hot nitric acid. Potassium phosphate is dissolved in water. Chromium is dissolved in hydrochloric acid, diluted 1:1, followed by repeated Stripping of chlorine ion in hot nitric acid. Strontium nitrate is dissolved in nitric acid, diluted 1:2.

The solutions were transferred to volumetric flasks and topped up to the mark with nitric acid, diluted 1:2. The shelf life of solutions of known concentration according to GOST 4212.

Tin dissolves in sulphuric acid, the solution was transferred to volumetric flask and topped to the mark with sulfuric acid diluted 1:2.

Powder of tin dissolved in nitric acid, diluted 1:2, in an ice bath with stirring, the solution is used within 1 h.

Tantalum is dissolved in a mixture of nitric and fluoride-hydrogen acid, followed by repeated Stripping of the fluoride ion hot nitric acid.

The resulting solution was cooled, transferred to a volumetric flask and topped to the mark with a solution of tartaric acid mass concentration of 0.15 g/cm. A solution of tantalum is stored in a plastic container.

The estimated volumes of solutions with known content of elements enter into the solution of Nickel and mixed. If necessary, take into account the mass fraction of impurities in the metal used to prepare the solution of Nickel.

After that injected silicon in the form of an aqueous slurry of silicon oxide or solution tetrachloro ester of silicic acid in ethyl alcohol, the solution is used within 1 h.

The resulting solutions evaporated to dry salts and calcined in a muffle furnace at a temperature of (825±25) °C. the Calcined mixture of oxides is cooled, crushed to a powder in a mortar or other method eliminating contamination of material from the standard samples. The average material mixing and is used for determining the metrological characteristics.

Material of standard samples stored in tightly closed cans or buksh under conditions that exclude contamination and moisture.

Appendix B (recommended). The procedure for verifying the suitability of the results of measurements of the intensity of analytical lines of elements when calculating the result of a single definition

Appendix B
(recommended)

Three difference values of pucherani (or intensity) of the analytical spectral lines find the mass fraction of the determined elements in the calibration schedule. Suitable considered three dimensions for which the condition

, (B. 1)

where , and are the values on the mass fraction of the element corresponding to highest, lowest and average of the three difference values of pucherani (or intensity);

 — relative value allowable discrepancies between and , the recommended value for aluminum, bismuth, gallium, indium, cadmium, calcium, silicon, copper, arsenic, magnesium, selenium, silver, antimony, thallium, tellurium and phosphorus to 0.50, other elements of 0.33.

If this condition is not met, it is allowed to exclude the result, the most remote of the average. The remaining two dimensions are considered suitable, if the condition

, (B. 2)

where , and are the values on the mass fraction of the element corresponding to highest, lowest and average of the two remaining values of the difference of pochernenija (or intensity). If this condition is not fulfilled, then carry out the analysis of additional tablets of the same sample to obtain results that satisfy the conditions (B. 1) (B. 2).

Bibliography