GOST 1953.5-79

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  ГОСТ 1953.5-79

GOST 1953.5−79 Bronze tin. Methods for determination of Nickel (with Amendments No. 1, 2)

GOST 1953.5−79

Group B59

INTERSTATE STANDARD

BRONZE TIN

Methods for determination of Nickel

Tin bronze.
Methods for the determination of nickel

AXTU 1709

Date of introduction 1981−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

2. APPROVED AND ENTERED INTO EFFECT by the Decree of the USSR State Committee for standards from 10.10.79 N 3899

3. The standard fully complies ST SEV 1535−79

4. REPLACE GOST 1953.5−74

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Limitation of actions taken by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification (ICS 11−12−94)

7. EDITION with Amendments No. 1, 2 approved in February 1983, August 1990 (IUS 6−83,11−90)

This standard specifies the photometric (with a mass fraction of Nickel from 0.05% to 2.5%), gravimetric (mass fraction in Nickel from 0.9% to 2.5%) and atomic absorption (at a mass fraction of Nickel from 0.05% to 2.5%) methods for determination of Nickel in tin bronze according to GOST 5017, GOST GOST 613 and 614.

The standard fully complies ST SEV 1535−79.

(Changed edition, Rev. N 1, 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 25086 with the Supplement according to claim 1.1 GOST 1953.1.

(Changed edition, Rev. N 1, 2).

2A. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF NICKEL

2A.1. The essence of the method

The method is based on formation of Nickel coloured compounds with dimethylglyoxime in an alkaline medium in the presence of an oxidant and measuring the optical density of colored solution.

Sec. 2A. (Added, Rev. N 1).

2. APPARATUS, REAGENTS AND SOLUTIONS

Photoelectrocolorimeter or spectrophotometer.

Installation of electrolysis.

The electrodes are platinum according to GOST 6563.

Nitric acid according to GOST 4461, diluted 1:1 and 1:100

Sulfuric acid according to GOST 4204, diluted 1:4.

Citric acid according to GOST 3652, a solution of 100 g/DM.

Sodium hydroxide according to GOST 4328, 2 mol/DMsolution.

Ammonium nitrate according to GOST 22867, solution 20 g/lin nitric acid, diluted 1:100.

Ammonium neccersarily (persulfate) according to GOST 20478, a freshly prepared solution of 20 g/DM.

Dimethylglyoxime according to GOST 5828, a solution of 10 g/DM2 mol/DMsolution of sodium hydroxide.

Nickel GOST 849, stamps D0.

Standard solutions of Nickel.

Solution A, prepared as follows: 0.2 g of Nickel dissolved in 20 cmof nitric acid, diluted 1:1. Remove the oxides of nitrogen by boiling. The solution was transferred to volumetric flask with a capacity of 1 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.0002 g of Nickel.

Solution B is prepared as follows: 25 cmsolution And placed in a volumetric flask with a capacity of 250 cm, made up to the mark with water and mix.

1 cmof solution B contains 0,00002 g of Nickel.

(Changed edition, Rev. N 2).

3. ANALYSIS

3.1. The weight of bronze weighing 0.5 g were placed in a glass with a capacity of 250 cm, add 15 cmof nitric acid, diluted 1:1, cover with a watch glass and dissolved under heating. After dissolution, the watch glass and walls of glass is then rinsed with water and the solution is evaporated to 5−10 cm. To the residue add 50 cmof hot water, 20 cmof hot ammonium nitrate solution and allowed to stand in a warm place for 1 h. the Precipitate metalbands acid is filtered off on a tight filter with filtrowanie mass and washed the filter with the precipitate in hot nitric acid, diluted 1:100 prior to the complete removal of Nickel (test with dimethylglyoxime).

The filtrate, whose volume is 150 cm, is electrolyzed for separating lead and copper when a current of 1.5−2 And with stirring. After 30 min after the start of electrolysis, add 7 cmof sulphuric acid, diluted 1:4.

After the separation of copper and lead electrodes are removed, washed their 20−25 cmof water, the solution was transferred to volumetric flask with a capacity of 250 cm, the glass is rinsed 3−4 times with water (10−12 cm), made up to the mark with water and mix.

Aliquot part of the solution (see table.1) is placed in a volumetric flask with a capacity of 50 cm, is diluted with water to 20 cm, and was added with stirring 5 cmof the citric acid solution, 3 cmsolution naternicola ammonium 8 cmof sodium hydroxide solution and 5 cmof the solution dimethylglyoxime, made up to the mark with water and mix.

Table 1

After 20−30 min, measure the optical density of the solution in cuvette with thickness of absorbing layer 1 cm relative to the solution in the reference experiment on the spectrophotometer at a wavelength of 450 nm or photoelectrocolorimeter with a blue filter.

(Changed edition, Rev. N 1).

3.2. (Deleted, Rev. N 2).

3.3. Construction of calibration curve

In a volumetric flask with a capacity of 50 cmplaced consistently 0; 1,0; 2,0; 3,0; 4,0; 5,0; 6,0 and 8.0 cmof a standard solution B of Nickel, dilute with water to 20 cmand then do as described in claim 3.1.

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of Nickel () in percent is calculated by the formula

,

where is the mass of Nickel was found in the calibration schedule g;

 — the weight of the portion corresponding to aliquote part of the solution,

4.2. Discrepancies between the results of the parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3) specified in table.2.

Table 2

(Changed edition, Rev. N 2).

4.3. Discrepancies in the results analysis, obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values specified in table.2.

4.4. Control of accuracy of analysis results is carried out according to State standard samples of tin bronzes, re-approved by GOST 8.315, or comparison of results obtained by gravimetric or atomic absorption methods, in accordance with GOST 25086.

4.5. The photometric method is used in case of disagreement in assessing the quality of tin bronzes.

4.3−4.5. (Added, Rev. N 2).

5. GRAVIMETRIC METHOD FOR THE DETERMINATION OF NICKEL

5.1.The essence of the method

The method is based on the deposition of Nickel from ammoniacal solution by dimethylglyoxime in the presence of citric and tartaric acids in the form of insoluble chelate dimethylglyoximate of Nickel, and weighing the resulting precipitate.

5.2. Apparatus, reagents and solutions

Electrolysis setup with a platinum mesh electrode according to GOST 6563.

Crucibles filter according to GOST 25336, types TF 3−20, 3−22.

Nitric acid according to GOST 4461, diluted 1:1 and 1:99.

Tartaric acid according to GOST 5817, a solution of 250 g/DM.

Citric acid according to GOST 3652, a solution of 250 g/DM.

Ammonia water according to GOST 3760 and diluted 1:50.

Ammonium nitrate according to GOST 22867, a solution of 100 g/DM.

Ammonium chloride according to GOST 3773, a solution of 200 g/DM.

Sodium acetate according to GOST 199.

Ammonium vinocity according to GOST 4951.

The solution for washing the precipitate; prepared as follows: 10 g Vinokurova ammonium dissolved in water, add 1 cmof ammonia and add water to 1000 cm.

Urea according to GOST 6691, a solution of 50 g/DM.

Ethyl alcohol, rectified according to GOST 18300.

Dimethylglyoxime according to GOST 5828, alcoholic solution of 10 g/DM.

Bronchiology blue, alcoholic solution of 10 g/d

m.

5.3.Analysis

The weight of bronze weighing 1.0 g was placed in a beaker with a capacity of 250 cm, and dissolved in 10 cmof nitric acid, diluted 1:1, when heated. Boiling removes oxides of nitrogen, add 50 cmof hot water, 20 cmof hot ammonium nitrate solution and gently heated for 10 min. if necessary filter the solution through a dense filter, filtrowanie mass in a beaker with a capacity of 250 cm. The filter cake was washed 7−8 times with hot solution of nitric acid, diluted 1:99, and the precipitate discarded. The filtrate is diluted with water to 150 cmand a copper and lead by electrolysis according to GOST 1953.1. When you are prompted during the electrolysis of pink color (oxidized form of manganese) is added dropwise a solution of urea or hydrazine sulphate to a bleaching solution.

The electrolyte was transferred to a beaker with a capacity of 500 cmand dilute with water to 200 cm, add 10 cmof a solution of tartaric or citric acid, 25 cmof a solution of ammonium chloride and neutralized with ammonia to slightly acid reaction (рН4−5) on universal indicator paper or add a few drops of blue bromtimol and ammonia to alkaline reaction, then add dropwise nitric acid diluted 1:1, to change the color of the solution. The solution is heated to 70 °C, add 30 cmdimethylglyoxime alcohol solution, 5 g sodium acetate, mix, add 2−3 cmof ammonia solution until slightly alkaline reaction solution and incubated at 50 °C for 2 hours (can leave overnight). The resulting precipitate was filtered on pre-weighed dry filter crucible in the extraction solution water-jet pump. The residue in the crucible was washed 3 times with hot solution of washing 6−8 times with hot water, the crucible and the precipitate was dried at 120 °C to constant

mass.

5.4. Processing of the results

5.4.1. Mass fraction of Nickel () in percent is calculated by the formula

,

where is the mass of sediment dimethylglyoximate Nickel, g;

0,2032 — the ratio of the mass of dimethylglyoximate of Nickel mass of Nickel;

 — the weight of the portion,

5.1−5.4.1. (Changed edition, Rev. 1).

5.4.2. Discrepancies in the results of parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3) specified in table.2.

(Changed edition, Rev. N 2).

5.4.3. Discrepancies in the results analysis, obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values specified in table.2.

5.4.4. Control of accuracy of analysis results is carried out according to State standard samples of tin bronzes, re-approved by GOST 8.315, or a comparison of the results obtained photometric or atomic absorption method, in accordance with GOST 25086.

5.4.3, 5.4.4. (Added, Rev. N 2).

6. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF NICKEL

6.1.The essence of the method

The method is based on measuring the absorption of light by atoms of Nickel, formed during the introduction of the analyzed solution in the flame acetylene-air.

6.2. Apparatus, reagents and solutions

Atomic absorption spectrometer with a radiation source for Nickel.

Nitric acid according to GOST 4461 and diluted 1:1.

Hydrochloric acid according to GOST 3118 and 2 mol/DMsolution.

A mixture of acid: mix one volume of nitric acid with three volumes of hydrochloric acid.

Nickel GOST 849.

Standard solutions of Nickel.

Solution a: 1 g of Nickel is dissolved by heating in 10 cmof nitric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 1 DMand topped to the mark with water.

1 cmof the solution contains 0.001 g of Nickel.

Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cmand top up with water to the mark.

1 cmof a solution contains 0.0001 g of Nickel

.

6.3. Analysis

6.3.1. A portion of the bronze mass, given in table.3, is dissolved by heating in 10 cmof a mixture of acids. The solution is transferred to the appropriate volumetric flask (see table 3) and top up with water to the mark. When the content of Nickel of more than 0.1% of aliquot part of the solution (table.3) is placed in a volumetric flask with a capacity of 100 cm, flow 10 cmof 2 mol/DMof hydrochloric acid and add water to the mark.

Table 3

Measure the atomic absorption of Nickel in the flame acetylene-air at a wavelength of 232,0 nm parallel to the calibration solutions.

6.3.2. Construction of calibration curve

In six of the seven volumetric flasks with a capacity of 100 cmplaced 1,0; 2,0; 4,0; 6,0; 8,0; and 10.0 cmof a standard solution of Nickel B.

To all flasks add 10 cmof 2 mol/DMhydrochloric acid solution and add water to the mark.

Measure the atomic absorption of Nickel, as specified in clause 6.3.1. According to the obtained results build a calibration curve.

6.4. Processing of the results

6.4.1. Mass fraction of Nickel () in percent is calculated by the formula

,

where is the concentration of Nickel was found in the calibration schedule, g/cm;

 — the volume of the final sample solution, cm;

 — the weight of the portion of the sample,

6.4.2. Discrepancies in the results of parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3) specified in table.2.

6.4.3. Discrepancies in the results analysis, obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values specified in table.2.

6.4.4. Control the accuracy of the results of the analysis carried out according to State standard samples of tin bronzes, re-approved by GOST 8.315, or by additives or by comparison of the results obtained photometric or gravimetric methods in accordance with GOST 25086.

Sec. 6. (Added, Rev. N 2).