GOST 12227.0-76

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  ГОСТ 12227.0-76

GOST 12227.0−76 Rhodium. Method of spectral analysis (with Amendments No. 1, 2, 3)

GOST 12227.0−76

Group B59

STATE STANDARD OF THE USSR

RHODIUM

Method of spectral analysis

Rodium. Method of 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

V. A. Korneev; V. E. Avramov, PhD. tech. Sciences; M. A. Gavrilov; A. K. Dementiev, head of the work; I. I., Karshakevich

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 23.07.76 N 1774

3. The frequency of inspection 5 years

4. REPLACE GOST 12227−66 in part of sec. 1, 2

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Limitation of actions taken on the Protocol, the Interstate Council for standardization, Metrology and certification (ICS 2−93)

7. REVISED (June 1997) with Amendments No. 1, 2, 3, approved in January 1982, June 1987-February 1993 (IUS 4−82, 10−87, 9−93)

This standard applies to rhodium and sets the spectral method of determining the mass fraction of platinum, palladium, iridium, ruthenium, gold, silver, copper, Nickel, iron, titanium, silicon, barium, lead, aluminum, tin, magnesium.

The method is based on evaporation of metal from the crater of the graphite electrode arc AC. The impurities determined in the following concentrations: platinum, palladium, iridium, ruthenium from 0.005 to 0.1% each; iron, Nickel, titanium, silicon, gold, and lead from 0.001 to 0.05% each; silver, copper, tin, barium, aluminium — 0.001 to 0.01 percent of magnesium, from 0.0005 to 0.01%.

(Changed edition, Rev. N 1, 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis according to GOST 22864.

1.2−1.4. (Deleted, Rev. N 2).

1.5. Sample taking with an accuracy of 0.005 g.

(Added, Rev. N 1).

2. APPARATUS, MATERIALS AND REAGENTS

The diffraction spectrograph of a large dispersion with a grating 1200 strokes at 1 mm.

The generator is activated the arc AC.

Geregistreerde microphotometer.

Nine-reliever.

Analytical scale.

Graphite electrodes spectral-net with a diameter of 6 mm.

Rhodium calibration samples for the determination of impurities.

Phototechnical film FT-41 according to normative-technical documentation with a sensitivity not less than 0.5 units (for the mass concentration of rhodium of 99.9% and above), and photographic plates of the spectral type I sensitivity of 1−2 relative units, type II sensitivity 16 relative units for the mass concentration of rhodium less than 99.9%. Dishes, buxy, desiccators for storage of samples and calibration samples, tweezers for the treatment of photographic films or photographic plates.

Table lathe with a set of tools for sharpening graphite electrodes.

Rectified ethyl alcohol according to GOST 5962* to clean sealed jars, weights and all equipment.
______________
* On the territory of the Russian Federation GOST R 51652−2000. — Note the manufacturer’s database.

Film positive-type M3−3-35 sensitivity of 0.7−1.0 units according to GOST 20945.

Developer and fixer according to GOST 10691.0, GOST 10691.1. Allowed to use other contrast working developer.

Standard sample of rhodium to verify the correctness of analysis results.

(Changed edition, Rev. N 1, 2, 3).

3. PREPARATION FOR ASSAY

3.1. The sample to be analyzed must be in the form of powder with particle size less than 0.3 mm, chips, wire or ribbon. From the analyzed samples are taken of sample to 100 mg.

3.2. Sample sample standard sample and calibration samples are placed in the crater of a thin-walled graphite electrode (diameter 3.5−4.0 mm, depth 1.5−2.0 mm). The counter serve as graphite rods with a length of 30−50 mm, sharpened to a truncated cone.

3.3. Calibration samples for spectral analysis were prepared by mechanical mixing of powders of impurities (mark H. h, the particle size 0.15 mm) with powder-Foundation — with rhodium.

The purity of the rhodium check spectrographic method under the same conditions under which to conduct analysis. Impurities found in Rodia, determined by the method of additives, and found the mass fraction into account in the preparation of calibration samples.

First, prepare the parent sample from which to select a few samples to check the homogeneity of the distribution of impurities. Then the parent sample is diluted with rhodium to obtain a series of seven calibration samples in the range of mass fraction from 0.001 to 0.1%.

Allowed the preparation of calibration samples in a different way.

(Changed edition, Rev. N 1, 2).

4. ANALYSIS

4.1. Spectra of calibration samples standard sample and the sample photographed on the spectrograph under the following conditions: the slot width of 0.015 mm, the light slit being a condenser, an arc gap of 2.5 mm, current intensity And 7−8, exposure 90 s. For the determination of barium and magnesium in the spectra of the calibration samples are photographed at a current of 5 A. the Exposition of 20 s.

Allowed to apply a constant current. The electrode with the sample is used as the anode.

The interelectrode distance of 2.5 mm adjust in the process of exhibiting spectra in the image on the intermediate diaphragm.

The spectra are photographed on a positive film M3−35. Allowed to apply spectral photographic plates of types I and II. Film show for 5 min at developer temperature of 20 °C. photographic Plates show over 4 mins of the exposed photographic plates and film in the rinse water. Fixed, washed in running water, dried and photometric.

(Changed edition, Rev. N 2, 3).

4.2. (Deleted, Rev. N 2).

5. PROCESSING OF THE RESULTS

5.1. When fotomaterialy lines of impurities take into account the background. The intensity of the background subtracted from the intensity of the analytical lines of impurities with the help of characteristic curve. The determination of the concentrations of all impurities produced by the method of «three standards».

Analytical lines are recommended for analysis, are shown in table 1.

Table 1

Calibration graphs constructed in the coordinates: x-axis calibration samples on the y-axis .

With the help of calibration chart, find the mass fraction of impurities in the analyzed samples. The final result of the analysis be the arithmetic mean of four parallel measurements, the maximum difference between them does not exceed the admissible discrepancy at a confidence probability of 0.95.

(Changed edition, Rev. N 1).

5.2. Permissible discrepancies in the results of parallel definitions should not exceed the values given in table.2.

Table 2

(Changed edition, Rev. N 2).