GOST 9519.3-77

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  ГОСТ 9519.3-77

GOST 9519.3−77 Babbit calcium. The method of atomic absorption spectral analysis (with Amendments No. 1, 2)

GOST 9519.3−77

Group B59

INTERSTATE STANDARD

CALCIUM BABBITS

The method of atomic absorption spectral analysis

Lead-calcium bearing alloys. Method of atomic-absorbing spectral analysis

AXTU 1709

Date of introduction 1978−01−01

INFORMATION DATA

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

DEVELOPERS

B. C. Chumachenko, L. I. Punin, V. I. Petrov, A. I. Pogonina, S. D. Demchenko, R. P. Petrova

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 15.04.77 N 946

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)

6. EDITION (July 2000) with Amendments No. 1, 2, approved in October 1982, June 1987 (ICS 1−83, 10−87)


This standard establishes the method of atomic absorption spectral analysis of calcium babbits.

The method is based on measurement of absorption spectra when introduced into the flame the calibration solutions and solutions of analyzed samples.

Method sets the determination of impurities and main components of calcium babbits in the range of mass fraction of, %:

calcium is from 0.1 to 1.2;

sodium is from 0.1 to 1.2;

of zinc, from 0.001 to 0.06.

(Changed edition, Rev. N 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis and security requirements — according to GOST 9519.0.

Sec. 1. (Changed edition, Rev. N 1).

2. EQUIPMENT AND REAGENTS

Spectrophotometer atomic absorption.

Air compressor providing air pressure of 1.5−2 at.

Analytical scale type ADV-200.

Cylinders with acetylene.

Sources of resonant radiation: the spectral lamp with a hollow cathode calcium lamp high quality, providing the emission of sodium and zinc.

Nitric acid according to GOST 4461, diluted 1:3 and 1:1.

Lead oxide by ND.

Calcium carbonate according to GOST 4530.

Sodium chloride according to GOST 4233.

Zinc metal according to GOST 3640 brand C0.

Distilled water.

Standard solutions of lead.

Solution And; is prepared as follows: 5 g of lead oxide is dissolved without heating in 40−50 cmof nitric acid, diluted 1:3. The solution was transferred to a volumetric flask with a capacity of 200 cm, made up to the mark with water and mix thoroughly.

Solution B; prepared as follows: 20 g of lead oxide is dissolved without heating in the 60−80 cmof nitric acid, diluted 1:3. The solution was transferred to a volumetric flask with a capacity of 250 cm, made up to the mark with water and mix thoroughly.

Standard solutions of calcium.

Solution And; prepare the following: 0.625 g of calcium carbonate, dried to constant weight, dissolve in nitric acid, diluted 1:1. The solution was transferred to a volumetric flask with a capacity of 250 cm, made up to the mark with water and mix thoroughly.

1 cmof solution A contains 1.0 mg of calcium.

Solution B; prepare by diluting 10 times a solution And.

1 cmof solution B contains 0.1 mg of calcium.

Standard solutions of sodium

Solution And; is prepared as follows: to 1.271 g of sodium chloride, dried to constant weight, dissolve in water. The solution was transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix thoroughly.

1 cmof solution A contains 1.0 mg sodium.

Solution B; prepare by diluting 10 times a solution A.

1 cmof solution B contains 0.1 mg of sodium.

Standard solutions of zinc

Solution And; is prepared as follows: 0.5 g of zinc metal is dissolved in nitric acid, diluted 1:1, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix thoroughly.

1 cmof solution A contains 1.0 mg of zinc.

Solution B; prepare by diluting 10 times a solution And.

1 cmof solution B contains 0.1 mg of zinc.

3. PREPARATION FOR ASSAY

3.1. For analysis of calcium babbits are preparing two series of calibration solutions. The contents of the designated impurities in a series must match the interval content of these impurities in the analyzed samples.

3.2. The first series of calibration solutions for the determination of calcium and sodium are prepared in accordance with the table.1.

Table 1

3.3. A second series of calibration solutions for the determination of zinc is prepared in accordance with the table.2.

Table 2

3.4. Aliquote of the typical solutions the first series is transferred to a volumetric flask with a capacity of 250 cm, the second series — with a capacity of 100 cm, injected at the 10 cmof nitric acid, diluted 1:3, made up to the mark with water and mix thoroughly.

3.5. To determine sodium and calcium weighed samples of 0.5 g, weighed with accuracy up to 0.0002 g, is dissolved without heating to 30−40 cmof nitric acid, diluted 1:3.

The solution was transferred to a volumetric flask with a capacity of 250 cm, made up to the mark with water and mix thoroughly.

3.6. To determine the zinc weighed sample 2 g, weighed with accuracy of 0.0002 g, is dissolved without heating in 40−50 cmof nitric acid, diluted 1:3.

The solution was transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix thoroughly.

4. ANALYSIS

4.1. The monochromator atomic absorption spectrophotometer derive the analytical line of the element, include a lamp with a hollow cathode, the emitting spectrum of the corresponding element, and sets the slit width of the monochromator.

4.2. Measurement conditions determined elements are given in table.3.

Table 3

4.3. The calibration solutions and the sample solution are sequentially sprayed into the flames, registering the magnitude of the photocurrent on the meter before and after spraying, find its average value and the average value of the photocurrent during spraying .

4.4. For each solution, the measurements produce three times.

4.5. According to the measured values of the photocurrent calculated values of optical density () according to the formula

and find the average values of optical density on parallel measurements for each solution .

Calibration curve based on the measurement results of the calibration solutions, plotting on the y-axis values and x — axis is the concentrations of the analyzed element .

For the linear part of calibration curve passing through the origin, the concentration of the analyzed element in the sample () in percent is calculated by the formula

,

where is the tangent of the angle of slope of calibration curve, calculated by the method of least squares according to the formula

,

where is the concentration of the element in the -th standard sample of the enterprise.

For the interval of concentrations with a nonlinear dependence , it is recommended to construct the calibration graphs in the coordinate .

4.6. Position monitoring of the calibration curve carried out according to standard samples periodically. The offset of the calibration curve is considered valid when the condition

,

where the result of the analysis, %;

 — mass fraction, given in the certificate of standard sample, %;

 — the allowable difference specified in table.4, %;

the value of the certified characteristics, %.

4.5, 4.6. (Added, Rev. N 2).

5. PROCESSING OF THE RESULTS

5.1. (Deleted, Rev. N 2).

5.2. For the results analysis be the arithmetic mean of results of three parallel measurements. The allowable divergence between the most differing data at a confidence level of 0.95 does not exceed the values given in table.4.

The numerical values of the results of the analysis should end with the figure of the same kind, and corresponding standard indicators of the chemical composition specified in the standards for grades.

Table 4

(Changed edition, Rev. N 1, 2).

5.3. The reproducibility of the analysis of the same samples (and ), made at different times in different laboratories according to this method, must satisfy the condition:

,

where  — the allowable difference in % specified in the table.4.

5.4. In case of contact with the result of the analysis of the critical region of the tolerance field on the element content in the alloy of a given brand (normalized border vintage composition according to GOST 1209), the sample is analyzed by chemical methods 1219.1 according to GOST-GOST 1219.8.

5.3, 5.4. (Added, Rev. N 2).