GOST 6674.4-96

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  ГОСТ 6674.4-96

GOST 6674.4−96 copper phosphorous Alloys. Method for the determination of bismuth

GOST 6674.4−96

Group B59

INTERSTATE STANDARD

COPPER PHOSPHOROUS ALLOYS

Method for the determination of bismuth

Copper-phosphorous alloys.
Method for determination of bismuth

ISS 77.120.30
AXTU 1709

Date of introduction 2001−07−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 107, Donetsk state Institute of non-ferrous metals (Danism)

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 10 dated 3 October 1996)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated December 19, 2000 N 384-St inter-state standard GOST 6674.4−96 introduced directly as state standard of the Russian Federation from July 1, 2001

4 REPLACE GOST 6674.4−74

1 Scope

This standard establishes the atomic absorption method for the determination of bismuth the content of 0.0008% to 0.02% copper-phosphorous alloys.

2 Normative references

The present standard features references to the following standards:

GOST 3760−79 Ammonia water. Specifications

GOST 4160−74 Potassium bromide. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 5845−79 Potassium-sodium vinocity 4-water. Specifications

GOST 6674.0−96 copper phosphorous Alloys. General requirements for methods of analysis

GOST 10157−79 Argon gaseous and liquid. Specifications

GOST 10928−90 Bismuth. Specifications

3 General requirements

General requirements — according to GOST 6674.0.

4 the essence of the method

The method is based on dissolving the sample in nitric acid, extraction the extraction of bismuth from bromidic solutions of cyclohexanone and measuring the atomic absorption of bismuth in aqueous solution reextract with flameless electrothermal atomizer.

5 Apparatus, reagents and solutions

Atomic absorption spectrophotometer with electrothermal flameless atomizer and complete accessories.

Argon gas according to GOST 10157.

Nitric acid according to GOST 4461, diluted 1:1; solution 0.1 mol/DM.

Potassium bromide (potassium bromide) according to GOST 4160 solution 2 mol/DM.

Ammonia water according to GOST 3760, diluted 4:1.

Potassium-sodium vinocity (potassium-sodium tartrate) 4-water (Sagatova salt) according to GOST 5845, a solution of 200 g/DM.

Cyclohexanone according to the current normative document.

The reextractant solution: mix 50 cmof ammonia solution, 50 cmof a solution of Rochelle salt and 125 cmwater.

Bismuth brand ВИ0 according to GOST 10928.

A standard solution of bismuth: 0.1 g of bismuth dissolved in 50 cmof dilute nitric acid (1:1). After removal of oxides of nitrogen by boiling the solution was cooled, transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with water and mix.

1 cmof the solution contains 0.0001 g of bismuth.

6 analysis

6.1 a sample of alloy weighing 2 g were placed in a glass with a capacity of 400 cm, dissolved in 20 cmof dilute nitric acid (1:1), cooled, transferred to a volumetric flask with a capacity of 50 cm, is diluted to the mark with water, mix and take aliquot part of the solution in accordance with table 1.


Table 1

6.2 the Solution obtained in 6.1, is placed in a separating funnel, add 5 cmof potassium bromide solution, bring the volume of the aqueous phase to 50 cm, add 10 cmof cyclohexanone and shake for 3 min.

After separation of the phases the aqueous phase is discarded and extravert bismuth 5 cmsolution reextractant. The reextractant filtered through a dry filter «white ribbon» in dry box with a glass lid.

6.3 For the construction of calibration curve in dry buxy with a glass cover placed 0; 0,05; 0,10; 0,20; 0,30; 0,40 and 0.50 cmstandard solution of bismuth, add 5,00; 4,95; 4,90; 4,80; 4,70; 4,60 and 4.50 cmreextractant solution, close lid and mix.

6.4 Preparatory actions required to bring the spectrophotometer to select the operating mode single-beam scheme with deuterium corrector of the background, is carried out in accordance with the manual.

6.5 20·10DMobtained according to 6.2 and 6.3 solution using the pipette contribute in a graphite furnace with argon flow on the platform with a pyrolytic coating and carry out the heating furnace according to the following program: 1st stage — at 90 °C for 30 s; stage 2 is gradual heating up to 200 °C for 30 s; stage-3 — at 2300 °C for 5 seconds at the stopped flow of argon. Record the magnitude of the atomic absorption of bismuth in the sample solution and the solutions for constructing the calibration curve at a wavelength of 306,4 nm.

6.6 According to the obtained results build a calibration curve in the coordinates: «the mass of bismuth in g — value of atomic absorption». Mass fraction of bismuth in the sample is determined directly according to the calibration schedule.

6.7 along with the analysis of alloy spend control experience.

7 Processing of results

7.1 Mass fraction of bi , %, is calculated by the formula

, (1)

where is the mass of bismuth in the analyzed sample solution determined by calibration schedule g;

 — the mass of bismuth in the solution of control and experience determined by the calibration schedule g;

 — the weight of the portion of alloy, suitable aliquote part of the solution,

7.2 discrepancies in the results of parallel measurements and the results of the analysis shall not exceed allowable (at confidence probability of 0.95) of the values given in table 2.


Table 2

Percentage