GOST R 52519-2006

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  ГОСТ Р 52519-2006

GOST R 52519−2006 Platinum. Method of atomic-emission analysis with inductively coupled plasma

GOST R 52519−2006

Group B59

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Platinum

METHOD OF ATOMIC-EMISSION ANALYSIS
INDUCTIVELY COUPLED PLASMA

Platinum. Method of inductively coupled plasma atomic-emission analysis

OKS 39.060

Date of introduction 2006−07−01

Preface

The objectives and principles of standardization in the Russian Federation established by the Federal law of 27 December 2002 N 184-FZ «On technical regulation», and rules for the application of national standards of the Russian Federation — GOST R 1.0−2004 «Standardization in the Russian Federation. The main provisions"

Data on standard

1 DEVELOPED by the Open joint-stock company «Prioksky nonferrous metals plant» (OJSC pztsm), an Open joint stock company «Irgiredmet» (JSC «Irgiredmet»), a Public institution on formation of the State Fund of precious metals and precious stones of the Russian Federation, storage, holiday and use of precious metals and precious stones (Gokhran of Russia) under the Ministry of Finance of the Russian Federation

2 SUBMITTED by the Technical Committee for standardization TC 102 «Platinum metals"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology from February, 6th, 2006 N 2-St

4 INTRODUCED FOR THE FIRST TIME


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 (replacement) or cancellation of this standard a notification will be published in a 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 applies to affilirovannuju platinum bullion and powder with a mass fraction of platinum not less than 99.8%, designed for the production of alloys, semi-finished products, chemical compounds of platinum and other purposes.

The standard specifies atomic emission (inductively coupled plasma) method for determination of impurities, aluminum, bismuth, iron, gold, iridium, cadmium, calcium, silicon, magnesium, manganese, copper, molybdenum, arsenic, Nickel, tin, palladium, rhodium, ruthenium, lead, silver, antimony, tellurium, chromium, zinc and zirconium / platinum. The method allows to determine the content of impurities in the intervals given in table 1.


Table 1 — Intervals of the contents of the designated elements

The analysis method is based on excitation of atoms of the sample in inductively coupled plasma and measuring the intensity of analytical lines defined element when spraying a solution of the sample into the plasma. The relationship of the intensity of lines with the concentration of the element in the solution set with the help of the calibration dependence.

2 Normative references

This standard uses the regulatory references to the following standards:

GOST R 8.563−96 State system for ensuring the uniformity of measurements. Methods of measurement

GOST R ISO 5725−1-2002 Accuracy (trueness and precision) of methods and measurement results. Part 1. General provisions and definitions

GOST R ISO 5725−3-2002 Accuracy (trueness and precision) of methods and measurement results. Part 3. Intermediate indicators the precision of a standard measurement method

GOST R ISO 5725−4-2002 Accuracy (trueness and precision) of methods and measurement results. Part 4. The main methods of determining the correctness of a standard measurement method

GOST R ISO 5725−6-2002 Accuracy (correctness and precision) of methods and measurement results. Part 6. The use of precision values in practice

GOST R 52244−2004 Palladium refined. Specifications

GOST R 52245−2004 Platinum affilirovannaja. Specifications

GOST 804−93 primary Magnesium ingots. Specifications

GOST 849−97 Nickel primary. Specifications

GOST 859−2001 Copper. Brand

GOST 860−75 Tin. Specifications

GOST 1089−82 Antimony. Specifications

GOST 1467−93 Cadmium. Specifications

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

GOST 3640−94 Zinc. Specifications

GOST 3765−78 Ammonium molybdate. Specifications

GOST 3778−98 Lead. Specifications

GOST 4530−76 Calcium carbonate. Specifications

GOST 5905−2004 metal Chrome. Technical requirements and delivery conditions

GOST 6008−90 metallic Manganese and nitrated manganese. Specifications

GOST 6835−2002 Gold and gold alloys. Brand

GOST 6836−2002 Silver and silver alloys. Brand

GOST 10157−79 Argon gaseous and liquid. Specifications

GOST 10928−90 Bismuth. Specifications

GOST 11069−2001 primary Aluminium. Brand

GOST 11125−84 nitric Acid of high purity. Specifications

GOST 12338−81 Iridium powder. Specifications

GOST 12340−81 Palladium bullion. Specifications

GOST 12342−81 Rhodium powder. Specifications

GOST 12343−79 Ruthenium powder. Specifications

GOST 13610−79 carbonyl Iron radio. Specifications

GOST 14261−77 hydrochloric Acid of high purity. Specifications

GOST 14262−78 sulphuric Acid of high purity. Specifications

GOST 17614−80 Tellurium technical. Specifications

GOST 19658−81 Silicon monocrystalline in ingots. Specifications

GOST 22861−93 Lead of high purity. Specifications

GOST 24104−2001 laboratory Scales. General technical requirements

GOST 24363−80 Potassium hydroxide. Specifications

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

GOST 28058−89 Gold bullion. Specifications

GOST 28595−90 Silver bullion. Specifications

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

OST 6−12−112−73* Arsenic metal, high purity. Specifications

________________

* The document is not given. For additional information, please refer to the link. — Note the manufacturer’s database.


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 document is replaced (modified), then the use of this standard should be guided by the replaced (modified) document. If the reference document is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.

3 Terms and definitions

This standard applies the terminology according to GOST R ISO 5725−1 and GOST R 8.563.

4 Accuracy (trueness and precision) of the method

4.1 indicators of the accuracy of the method

Indicators of accuracy of the method: the limit of absolute error of the results of the analysis (the boundaries of the interval in which the measurement uncertainty is with a probability of 0.95), the standard deviation of repeatability and intermediate precision, the values of the limit of repeatability , intermediate precision and reproducibility limit depending on the mass fraction of the element — impurities are shown in table 2.


Table 2 — indicators of the accuracy of the method (0,95)

Percentage

4.2 Correctness

To estimate the systematic error of the present method for the determination of all elements (impurities) in platinum should be used as a reference certified value mass fraction of elements in the state standard samples of composition of platinum (set PL-35) GSO 7351−97 or other GEO, the next set of detectable elements and metrological characteristics.

Systematic error of the method at the significance level 5% nonsignificant according to GOST R ISO 5725−4 for all determined elements (impurities) in platinum at all levels of the designated contents.

4.3 Precision

4.3.1 the Range of results of the two determinations, obtained for the same sample by one operator using the same equipment within the shortest possible time intervals that may exceed the specified in table 2 the limit of repeatability according to GOST R ISO 5725−6 on average not more than once in 20 cases with proper use of the method.

4.3.2 within a single laboratory result analysis of the same sample obtained by different operators using the same equipment on different days, can vary with the excess specified in table 2 of the limit of intermediate precision according to GOST R ISO 5725−3 on average not more than once in 20 cases with proper use of the method.

4.3.3 the results of the analysis of the same samples, obtained in two laboratories in accordance with sections 6, 7, 8 of this standard may vary in excess of the limit of reproducibility according to GOST R ISO 5725−1 specified in table 2, on average not more than once in 20 cases with proper use of the method.

5 Requirements

5.1 General requirements and safety requirements

General requirements, requirements for security of works and environmental safety — according to the normative documents on the General requirements for methods of analysis of precious metals and alloys.

5.2 qualifications of performers

The analysis allowed persons over the age of 18, trained in the prescribed manner and allowed to work independently on the emission spectrometer.

6 measurement Means, auxiliary devices, materials and reagents

Atomic emission spectrometer with inductively coupled plasma, with a range of wavelengths from 180 to 500 nm, and with the possibility of the procedure of correction of the background.

Laboratory scales according to GOST 24104 with a limit of permissible absolute error of less than +0,0002 g.

Electric stove with a closed spiral.

Muffle furnace with temperature controller with heating temperature up to 1000 °C.

Drying Cabinet.

Argon gas according to GOST 10157.

Pipette 1−1-1−1, 1−1-1−2, 1−1-1−5, 1−1-1−10 according to GOST 29227.

Volumetric flasks 1−25−2, 1−50−2, 1−100−2 according GOST 1770.

Beakers 50, 100, 500 and 1000 according to GOST 1770.

The glasses are In 1−100 TCS-1−250 TCS according to GOST 25336.

Funnel In-56−80 TC GOST 25336.

Cups for weighing (buxy) glass according to GOST 25336.

Teflon beakers with lids capacity from 50 to 100 cm.

Polyethylene or Teflon jars with a capacity of 100 cm.

Watch-glasses.

The agate mortar.

The corundum crucibles.

Medical forceps.

The filter paper obestochennye «blue ribbon» at [1].

Water, double-distilled in a glass apparatus.

Nitric acid is the OS.h. according to GOST 11125 and diluted 1:1.

Hydrochloric acid OS.h. according to GOST 14261 and diluted 1:1, 1:3, 1:5.

Sulfuric acid OS.h. according to GOST 14262 and diluted 1:9.

Barium peroxide (barium peroxide) OS.h. in [2].

Potassium hydroxide (potassium hydroxide) according to GOST 24363 and solutions of concentration 500 g/land 5 g/DM.

Ammonium molybdate (NH)MoO·4HO according to GOST 3765.

Gold GOST 6835 or GOST 28058.

Silver at 6836 or GOST GOST 28595.

Platinum brand PLA-0, Plap-0 in accordance with GOST R 52245 with a mass fraction of each impurity determined by no more than the lower limit of the interval content specified in table 1.

Palladium according to GOST 12340 or GOST R 52244.

Rhodium powder according to GOST 12342.

Iridium powder according to GOST 12338.

Ruthenium powder according to GOST 12343.

Copper according to the GOST 859.

Radio engineering carbonyl iron according to GOST 13610.

Lead of high purity according to GOST 22861 or GOST 3778.

Zinc GOST 3640.

Nickel GOST 849.

Tin GOST 860.

Antimony GOST 1089.

Silicon monocrystalline in ingots according to GOST 19658.

Aluminium metal according to GOST 11069.

Magnesium GOST 804.

Calcium carbonate according to GOST 4530.

Zirconium (IV) oxychloride according to [3].

Bismuth GOST 10928.

Manganese metal according to GOST 6008.

Chrome metal according to GOST 5905.

Arsenic metal OS.h. for OST 6−12−112.

Tellurium GOST 17614.

Cadmium metal according to GOST 1467.

Standard samples of composition of platinum with an error of certified values of the content of impurities not exceeding 1/3 of the value characteristics error of the present method for each level of content.

Mass fraction of main substance in the metals used and the reagents is at least 99.9%, unless otherwise specified.

Allowed the use of other measurement means, auxiliary devices, materials and reagents, subject to obtaining accuracy rate that rivals those in table 2.

7 Preparation for assay

7.1 Preparation of basic solutions

7.1.1 Solutions containing 2 mg/ cmof rhodium, iridium, ruthenium

A portion of the metal mass of 200.0 mg was mixed thoroughly with 5-fold quantity of peroxide of barium, fray in an agate mortar, transferred to a corundum crucible and sintered in air for 2−3 h at temperatures from 800 °C to 900 °C (put the crucible in a cold muffle furnace). Sintered is cooled, transferred to a beaker with a capacity of 200 cm, moistened with water and dissolved in a solution of hydrochloric acid (1:1) until complete dissolution. If, after the dissolution of SPECA in hydrochloric acid solution precipitate, sintering and dissolution repeat. The resulting solution is diluted with water to a volume of 50 cmand precipitated barium sulfate by adding sulfuric acid solution (1:9) portions with constant stirring. The solution is heated to a temperature of from 60 °C to 70 °C. after 2−3 hours check the completeness of the precipitation of barium sulfate and filtered through filter «blue ribbon» in a volumetric flask with a capacity of 100 cm. The filter cake was washed 4−5 times with hot hydrochloric acid (1:5), and then 5−6 times with hot water. The solution was adjusted to the mark with hydrochloric acid (1:5) and stirred.

7.1.2 Solution containing 1 mg/cmsilver

A portion of silver with a mass of 100.0 mg dissolved in 10 cmof nitric acid (1:1) under heating, and then add 50 cmof hydrochloric acid and boil to complete dissolution of the precipitate of silver chloride. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with hydrochloric acid (1:1) and stirred.

7.1.3 Solutions containing 2 mg/cmof gold, antimony, arsenic, tellurium, tin

A portion of the metal mass of 200.0 mg dissolved in a mixture of hydrochloric and nitric acids (3:1) under heating. The solution is evaporated to a volume of 2 to 3 cm, add 20 cmof a hydrochloric acid solution (1:5), transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with the same acid solution and stirred.

7.1.4 the Solutions containing 2 mg/cmiron, copper, bismuth, Nickel

A portion of the metal mass of 200.0 mg dissolved in 10 cmof nitric acid (1:1) under heating. The solution is evaporated to a volume of 2 to 3 cm, add 20 cmof a hydrochloric acid solution (1:5), transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with the same acid solution and stirred.

7.1.5 Solution containing 2 mg/cmof lead

A portion of lead with a mass of 200.0 mg dissolved in 10 cmof nitric acid (1:1) under heating. The solution was transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

7.1.6 Solution containing 2 mg/cm palladium

The linkage of palladium with a mass of 200.0 mg dissolved in 20 cmof nitric acid when heated. The solution is evaporated to a volume of 2 to 3 cm, add 20 cmof a hydrochloric acid solution (1:5), transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with the same acid solution and stirred.

7.1.7 Solutions containing 2 mg/cmof aluminium, cadmium, chromium, manganese, zinc

A portion of the metal mass of 200.0 mg dissolved in 10 cmof hydrochloric acid (1:1) under heating. The solution was transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with hydrochloric acid (1:5) and stirred.

7.1.8 Solution containing 2 mg/cmmagnesium

A sample of magnesium with a mass of 200.0 mg dissolved in 10 cmof hydrochloric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with hydrochloric acid (1:5) and stirred.

7.1.9 Solution containing 2 mg/cmcalcium

Calcium carbonate is dried to constant weight at a temperature of from 100 °C to 105 °C, selected weighed mass 0,4994 g and dissolved in 10 cmof hydrochloric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

7.1.10 Solution containing 2 mg/cmof Zirconia

A sample of zirconium oxychloride mass of 0.7060 g dissolved in 10 cmof hydrochloric acid solution (1:3). The solution was transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with hydrochloric acid (1:5) and stirred.

7.1.11 Solution containing 2 mg/cmof molybdenum

A portion of molybdate of ammonium mass 0,3680 g dissolved in 20 cmof water. The solution was transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

7.1.12 Solution containing 1 mg/cmof silicon

A portion of the silicon mass of 100.0 mg dissolved in 20 cmof potassium hydroxide solution of concentration 500 g/DMin a Teflon-glass, closed the lid, under intense heating. The solution was cooled to room temperature and transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with a solution of potassium hydroxide concentration of 5 g/DMand immediately transferred into a polyethylene jar.

The use of other methods of preparation of key solutions and ready-to-use solutions of standard samples and certified mixtures, subject to receipt of the accuracy rate that rivals those in table 2.

7.2 Preparation of solution of platinum mass concentration of 100 mg/cm

A sample of platinum weighing 10.0 g is placed in a Teflon beaker with a capacity of 100 to 200 cm, add 50,0 cmwith a freshly prepared mixture of hydrochloric and nitric acids (3:1) the glass is closed with Teflon cap and dissolve platinum when heated. Every 2−3 hours add 10−15 cmof this mixture of acids to dissolve the sample. The solution is evaporated to a volume of 5−10 cm, add 10 cmof hydrochloric acid solution (1:5), transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with the same acid solution, stirred and transferred into dry plastic or Teflon jar

.

7.3 Preparation of intermediate solutions

7.3.1 Preparation of intermediate solutions containing palladium, rhodium, iridium, ruthenium, gold, iron, copper, lead, Nickel, tin, zinc, aluminum, magnesium and antimony

Solution a: a pipette is taken at 5.00 cmcore solutions of palladium, rhodium, iridium, ruthenium, gold, iron, copper, lead, Nickel, tin, zinc, aluminum, magnesium and antimony, and placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with hydrochloric acid (1:5) and stirred.

The mass concentration of each of the elements in the solution is of 100.0 µg/cm.

The limit of the absolute error values of the mass concentration of each element in the solution is 0.5 mg/ cm.

Solution B: take a pipette 10.00 cmof solution A and placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with hydrochloric acid (1:5) and stirred.

Mass concentration of each of these elements in solution is 10.00 µg/cm.

The limit of the absolute error values of the mass concentration of each element in solution is 0.07 mg/ cm

.

7.3.2 Preparation of intermediate solutions containing silver

Solution A1: taken with a pipette 10.00 cmof the basic silver solution and placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with hydrochloric acid (1:3) and stirred.

Mass concentration of silver in solution is of 100.0 µg/cm.

The limit of the absolute error values of the mass concentration of the solution is 0.5 mg/cm.

Solution B1: taken with a pipette 10.00 cmof the solution A1 and placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with hydrochloric acid (1:5) and stirred.

Mass concentration of silver in solution is 10.00 µg/cm.

The limit of the absolute error values of the mass concentration of a solution is 0.07 µg/s

m.

7.3.3 Preparation of intermediate solution containing a silicon

Solution A2: taken with a pipette 10.00 cmof the solution of the basic silicon and placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with water, mixed and immediately transferred to a Teflon or plastic jar.

Mass concentration of silicon in solution is of 100.0 µg/ cm.

The limit of the absolute error values of the mass concentration of the solution is 0.5 mg/cm.

Solution B2: taken with a pipette 10.00 cmof the solution A2 and placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with water, mixed and immediately transferred to a Teflon or plastic jar.

Mass concentration of silicon in solution is 10.00 µg/cm.

The limit of the absolute error values of the mass concentration of a solution is 0.07 µg/s

m.

7.3.4 Preparation of intermediate solutions containing arsenic, molybdenum, chromium, tellurium, cadmium, bismuth, manganese, calcium and zirconium

Solution A3: a pipette is taken at 5.00 cmcore solutions of arsenic, molybdenum, chromium, tellurium, cadmium, bismuth, manganese, calcium and zirconium and is placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with hydrochloric acid (1:5) and stirred.

The mass concentration of each of the elements in the solution is of 100.0 µg/cm.

The limit of the absolute error values of the mass concentration of each element in the solution is 0.5 mg/cm.

Solution BZ: taken with a pipette 10.00 cmof the solution A3 and placed in a volumetric flask with a capacity of 100 cm. The volume of the solution was adjusted to the mark with hydrochloric acid (1:5) and stirred.

Mass concentration of each of these elements in solution is 10.00 µg/cm.

The limit of the absolute error values of the mass concentration of each element in solution is 0.07 µg/s

m.

7.4 labelling Requirements and storage conditions of primary and intermediate solutions

On the flasks and jars with the basic and intermediate solutions should be affixed label indicating the mass concentration of the elements and date of preparation.

Basic and intermediate solutions are stored at room temperature in a container made of plastic (polyethylene, Teflon, etc.) with caps or plugs to ensure adequate tightness. Term storage of the basic solutions — 1 year. The shelf life of the interim solution is not more than 1 month at a mass concentration of 100 µg/cmand not more than 5 days at a mass concentration of 10 µg/cm.

7.5 sample Preparation for calibration

7.5.1 For the determination of impurities in platinum using samples for calibration: solutions with the mass concentration of determined elements is from 0.2 to 20 ug/cmof platinum and 40 mg/cm. Samples for calibration are prepared from intermediate solutions for 7.5.2 or from standard samples of composition of platinum at 7.5.3.

7.5.2 Preparation of samples for the calibration of the intermediate solutions

Pipettes are selected aliquote part mixes A, A1, A2 and A3, or B, B1, B2, and B3 (table 3), placed in a volumetric flask with a capacity of 25 cm, add 10 cmof a solution containing 100 mg/cmof platinum, adjusted to the mark with hydrochloric acid (1:5), stirred and immediately poured into plastic containers with caps or plugs to ensure adequate tightness.


Table 3 — Samples for calibration

Preparing a control sample to account for the purity of platinum and reagents used for preparing samples for calibration. This 10 cmof a solution containing 100 mg/cmof platinum, is placed in a volumetric flask with a capacity of 25 cm, adjusted to the mark with hydrochloric acid (1:5), stirred and immediately poured into plastic containers with lids or stoppers to ensure a good seal.

Solutions 1−4 (table 3) prepared on the day of use and stored for not more than 2 days, solutions, 5−7 (table 3) store no more than 5 days at room temperature.

7.5.3 Preparation of samples for the calibration of standard samples of composition of platinum

For graduation choose two or more standard samples of composition of platinum so that the content of each analyzed element — impurities in the analyzed sample was in the range interval between the lowest and highest values of the content of this element in the standard samples.

From each standard sample and take a weighed 1,000 g and translate it into a solution for 8.1.2−8.1.4. The resulting solutions stored for 5 days at room temperature.

8 analysis

8.1 Selection and preparation of samples

8.1.1 the Selection of laboratory samples for analysis from the ingot or powder / platinum is carried out in accordance with the procedure described in GOST R 52245. Laboratory a sample of platinum in the form of a powder or sponge is dried in a drying Cabinet at 105 °C — 110 °C to constant weight.

8.1.2 From laboratory sample of platinum taken two sample for 1,000 g each. In the analysis of platinum in the form of powder or sponge go to 8.1.3. In the analysis chip of platinum weighed pre-cleaned from impurities on the surface. For this the sample was placed in a Teflon beaker with a capacity of 50−100 cm, add 20 cmof hydrochloric acid (1:1) and boiled for 3−5 min. the Solution is decanted and the sample washed 6−7 times with water by decantation.

8.1.3 In a glass of linkage adds 20 cm ofa freshly prepared mixture of hydrochloric and nitric acids (3:1), closed with Teflon cap and dissolved platinum for 4−5 hours at high heat, adding every 30 min 5 cmof a mixture of hydrochloric and nitric acids (3:1). After complete dissolution of the sample Cup is removed from the plate, cooled, open the lid and carefully wash internal surface of the cap water in the beaker. The solution is evaporated to a volume of 3−5 cmand add 10 cmof hydrochloric acid solution (1:5).

8.1.4 the Solution was transferred to a volumetric flask with a capacity of 25 cm, adjusted to the mark with the same acid solution, mixed and immediately transferred to a plastic jar and close the lid. The resulting solution was supplied to the measurement.

8.1.5 Simultaneously through all stages of sample preparation to the analysis carried out control and experience on the purity of reagents used. To do this in two Teflon beakers with a capacity of 50−100 cmcarried out all the procedure 8.1.3 in the absence of the batches of platinum. The resulting solutions are transferred to volumetric flask with a capacity of 25 cm, adjusted to the mark with hydrochloric acid (1:5), stirred, and immediately transferred to a plastic jar and close the lid. The result is two solutions in the reference experiment.

If samples for calibration prepared from standard samples of composition of platinum, control and experience on the purity of reagents used is not carried out, provided that the dissolution of batches of standard samples and analyzed samples using the same acid solutions.

8.2 measurements

8.2.1 Spectrometer is prepared to work according to the instruction manual of the device. Enter into a program of measurements of the wavelengths of the analytical lines and background correction. Measurements are to begin not less than 30 min after ignition of the plasma to stabilize the measurement conditions. Time prezentirana — 30, the integration time is not less than 5 s.

The wavelengths of the analytical lines recommended for the analysis shown in table 4.


Table 4 — wavelengths of the analytical lines

The use of other analytical lines subject to receipt of the accuracy rate that rivals those in table 2.

8.2.2 To build the calibration dependencies used samples for calibration, prepared according to 7.5.2 or 7.5.3.

When performing measurements sequentially injected into the plasma samples for calibration and measure the intensity of the analytical lines of the determined elements minus background (the intensity of the radiation spectrum near the analytical line of the designated element). For each solution perform three measurements of the intensity of analytical lines of each element minus the background and calculate the average value.

8.2.3 If to obtain the calibration dependencies used samples for calibration, prepared according to 7.5.2, introduce a correction for the purity of platinum and reagents used for preparing samples for calibration. To do this, from the average value of the intensity of analytical lines of each element of the sample for calibration is subtracted the average value of the intensity of the analytical line of element control solution. Allowed to use other methods of accounting for the purity of reagents used subject to receipt of the accuracy rate that rivals those in table 2.

8.2.4 Calibration relationships are obtained in the coordinates: the average intensity value (adjusted the control solution) — mass concentration of the analyzed element in the sample for calibration (or mass fraction of the element in the standard sample of platinum).

8.2.5 Introduced sequentially into the plasma solutions in the reference experiment and analyze samples. Measured intensity of analytical lines of the determined elements (minus background). For each solution perform three measurements and calculate the average value. Using the calibration dependences find the value of the mass concentration of the element in the sample solution and platinum in solution in the reference experiment (when the samples for calibration were prepared 7.5.2) or from the mass share of element — impurities in the sample of platinum (if the samples for calibration were prepared by 7.5.3).

9 Calculation results of single definitions, evaluation of their acceptability and the achievement of a final result of the analysis

9.1 Mass fraction of the element in platinum in percent is calculated as follows.

9.1.1 If the solutions for calibration were prepared from standard samples of composition of platinum in 7.5.3, the mass fraction of the element in platinum obtained directly from the calibration dependence.

9.1.2 If the solutions for calibration were prepared from intermediate solutions for 7.5.2, the mass fraction of the element in platinum , %, is calculated by the formula

, (1)

where is the concentration of the analyzed element in the sample solution, µg/ cm;

 — the average value of the concentration of the element in solution in the reference experiment, µ g/cm;

 — the volume of the analyzed solution cm;

 — hanging platinum,

The median concentration of the element in solution in the reference experiment is calculated as the arithmetic mean value of results of parallel measurements of this element in two solutions controlling experience

.

9.2 the acceptability of the results of parallel measurements was evaluated in accordance with GOST R ISO 5725−6 by comparing the absolute differences of the results of two parallel measurements with a limit of repeatability in table 2.

If not exceed , the results of two parallel definitions recognize acceptable and for the final result of the analysis taking the arithmetic mean value of these results.

If exceeds , hold two parallel definitions. If the range of the results of four parallel samples () does not exceed the critical range for 4, as test results take the arithmetic mean value of the results of four parallel measurements.

The critical range is calculated by the formula

, (2)

where the 3.6 — the ratio of the critical range for four parallel measurements;

 — standard deviation of repeatability.

The values given in table 2.

If the range of the results of four parallel measurements exceed , as a final result of the analysis taking the median of the results of four parallel definitions, if normative documents of the enterprise provide otherwise.

10 Control of accuracy of analysis results

10.1 Control of intermediate precision and reproducibility

When monitoring intermediate precision (variable factors of the operator and time) is the absolute difference of the two results of the analysis of the same sample obtained by different operators using the same equipment on different days, should not exceed the limit of intermediate precision specified in table 2.

Under the control of the reproducibility of the absolute disparity of the two results of the analysis of the same samples, obtained in two laboratories, in accordance with the requirements of this standard must not exceed the limit of reproducibility shown in table 2.

10.2 verification of correct

The checking is carried out by analyzing standard samples of composition of platinum or samples for calibration, prepared at 7.5. The samples used for control of correctness should not be used to obtain the calibration dependencies.

When checking the difference between the analysis result and the accepted reference (certified) value of the content of element impurities in the standard sample should not exceed a critical value .

The critical value is calculated by the formula

, (3)

where  — the error of setting the reference (certified) value of the content of element impurities in the standard sample;

 — the limit of absolute error of the result of the analysis (values shown in table 2).