GOST 8857-77

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  ГОСТ 8857-77

GOST 8857−77 Lead. Method of spectral analysis (with Amendments No. 1, 2, 3)

GOST 8857−77

Group B59

STATE STANDARD OF THE USSR

LEAD

Method of spectral analysis

Lead. 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

HP Garcin, L. A. Kopylova

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 11.01.77 N 60

3. REPLACE GOST 8857−66

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. The expiration time limit is removed by the Resolution of Gosstandart from 08.04.92 N 376

6. REPRINT (October 1996) with Amendments No. 1, 2, 3, approved in January 1983, June 1987, April 1992 (IUS 5−83, 9−87, 7−92)


This standard applies to lead WITH the brands, S1S, C1, C2C, C2, C3 according to GOST 3778* and sets the spectrographic method for determination of impurities, silver, copper, bismuth, antimony, arsenic, tin, zinc, sodium, calcium, magnesium, chromium and iron.
________________
* On the territory of the Russian Federation GOST 3778−98. Here and hereinafter. — Note the manufacturer’s database.

The method is based on excitation and photographic registration of the emission spectra of the samples and standard samples with subsequent determination of content of impurities in the calibration schedule. When determining the content of silver, bismuth, copper used spark excitation spectra and in the determination of arsenic, antimony, tin, zinc, sodium, calcium, magnesium, chromium, iron — arc excitation, vaporizing the sample from a crater of the carbon electrode.

Spectrographic method allows you to define the following content of impurities in the lead, %:

bismuth — from 0.002 to 0.07;

copper — from 0.0004 inch to 0.0025;

silver — from 0.0002 to 0.0025;

sodium, calcium and magnesium — from of 0.0002 to 0.03;

antimony, arsenic and tin from 0.0004 inch to 0.0075;

zinc — from 0.0007 to 0.007 to;

chrome of 0.0005 to 0.00005;

iron from 0.0005 to 0,006.

(Changed edition, Rev. N 2, 3).

1. GENERAL REQUIREMENTS

1.1. Analysis carried out on samples taken and prepared according to GOST 3778, with the following addition: selected chips melted in a crucible pre-heated at 350−400 °C and cast into a mold in the form of electrodes of cylindrical shape with a diameter of 6−10 mm and length of 50−100 mm.

1.2. General requirements for methods of analysis GOST 25086.

(Added, Rev. N 2).

1a. SAFETY REQUIREMENTS

1a.1. In the analysis of lead in all work in the laboratory of spectral analysis should be carried out with instruments and electrical installations, the relevant regulations for electrical installations, approved by Gosenergonadzor.

Samples of lead submitted for analysis should be stored in packages of construction paper in a Cabinet or box, equipped with ventilation.

1A.2. In the use and operation of electrical appliances and electrical installations in the process of spectral analysis must comply with the rules of technical operation of electrical installations and safety rules at operation of electrical installations, approved by Gosenergonadzor, as well as the requirements of GOST 12.3.019.

1a.2.1. All appliances should be equipped with devices for grounding corresponding to GOST 12.2.007.0 and labeled according to GOST 21130. Grounding must be done in accordance with the rules of arrangement of electrical installations, approved by Gosenergonadzor, and GOST 12.1.018.

1a.2.2. In the analysis of lead using nitric and sulfuric acid, carbon electrodes, in the manufacture of which is formed of carbonaceous dust. When working with lead, nitric and sulfuric acids and carbon electrodes should observe security requirements outlined in the normative-technical documentation on their production and application, duly approved.

(Changed edition, Rev. N 2).

1a.2.3. When performing tests, it is necessary to observe the basic rules of safe work in chemical laboratories*.
________________
* On the territory of the Russian Federation the document is not valid. Acts PND f 12.13.1−03. — Note the manufacturer’s database.

1A.2.4. Preparation of samples for analysis must be carried out in boxes equipped with local exhaust ventilation according to GOST 12.4.021.

1A.3. To prevent contact with the air, lead, ozone, carbon and nitrogen oxides in quantities exceeding the maximum allowable concentration according to GOST 12.1.005, to protect from electromagnetic radiation and burns to ultraviolet rays each excitation source must be placed in a fixture equipped with local exhaust ventilation and protective screen according to GOST 12.1.019.

(Changed edition, Rev. N 2).

1a.3.1. The machine is used for grinding carbon electrodes must have a built-in pulariani exhaust ventilation to prevent carbon dust into the air space in amounts exceeding the maximum allowable concentrations.

1A.4. Control of content of harmful substances in the air of working zone according to GOST 12.1.007 and GOST 12.1.005.

Analyses of air samples for the content of harmful substances in the air of working zone is performed according to the methods of methods of determination of harmful substances in the air of working zone, approved by the USSR Ministry of health.

1A.5. Samples of lead, the remainder of the analysis must be returned to the manufacturer (customer). With the aim of environmental protection, the recycling, disposal and destruction of harmful substances from waste analyses must be performed in accordance with regulatory and technical documentation approved in the established order and agreed with the sanitary-epidemiological service of Ministry of health of the USSR.

1A.6. The premises of the laboratory of spectral analysis and their coverage must meet the CH-245−71 and SNiP II-4−79.

1A.6.1. The laboratory of spectral analysis must have General dilution ventilation — according to GOST 12.4.021.

1a.6.2. To ensure fire safety it is necessary to fulfill the requirements of GOST 12.1.004. The laboratory room must be equipped with means of fire extinguishing and fire fighting equipment according to GOST 12.4.009.

1a.6.3. In the analysis of lead in the laboratory of spectral analysis should be provided with special premises and devices according to SNiP 2.09.04−87 (for group IIIa of production processes).

1A.7. All work on tests must be performed in a dry, serviceable clothing, using protective equipment (rubber gloves, respirator, goggles) in accordance with standard industry regulations of free issue of workwear, footwear and protective equipment to workers and employees of the enterprises of nonferrous metallurgy. Clothing should be stored in racks separately from personal clothing, weekly renting it in the wash. Not allowed to make clothing, and also reside in it outside of the working space.

1A.7.1. Remove the lead from the hands and other contaminated body areas before washing with a solution of 1% acetic acid.

1A.7.2. Working in the spectral laboratories should be provided with therapeutic and preventive nutrition according to the rules of free issue of milk or other equivalent products to the workers and employees in factories, workshops, sections and other subdivisions with harmful working conditions.

1A.7.3. To work in the spectral laboratories should be open to persons trained in the basic techniques of working with instrumentation and electrical installations and methods of analysis in accordance with the rules of safety at operation of electroinstallations of consumers, approved by Gosenergonadzor.

1A.7.4. Re-entered the work, and must be held: preliminary and periodic medical examinations according to the instructions of the Ministry of health of the USSR; preliminary training in the work with hazardous substances and the rules for the treatment of protective equipment; safety instructions with the corresponding registration in the prescribed manner according to GOST 12.0.004.

Sec. 1a. (Added, Rev. N 1).

2. APPARATUS, MATERIALS AND REAGENTS

The quartz spectrograph medium dispersion of any type, diffraction-type DFS-8, a diffraction spectrograph with crossed dispersion-type STE-1 with a being system of the slit illumination and the three-step attenuator.

DC and AC 250−300 30−50 In A. the arc Generator for ignition of the arc DC high-frequency discharge.

Generator spark type IG-3.

Microphotometer of any type, allowing to measure the density of the blackening of analytical lines.

Furnace for fusing lead shavings.

Crucibles refractory graphite or graphite-refractory.

Mold for casting electrodes of cylindrical shape with a diameter of 6−10 mm and length of 50−100 mm.

Files for sharpening metal electrodes. Electrodes of graphite brand S-3 with the crater size of 3x3 mm and a wall thickness of 0.8−0.9 mm, electrodes of graphite of high purity with the size of the crater in a 4x4 mm (in the determination of chromium), and 3x3 mm (determination of iron), previously annealed in the arc AC or DC power 10 And 10−15 C.

Contradictory graphite, sharpened to a truncated cone with ground diameter of 1.5−2.0 mm.

Spectrographic plates of types 1, 2, UFS-3; «panchrom», SFC-02, the SFC-03.

Iron powder restored brand MLB-1 according to GOST 9849.

Infrared lamp for evaporation of any type with an auto-transformer type CTL-250−2.

The unit according to GOST 14919.

Muffle furnace with temperature up to 1000 °C.

Grinding machine carbon electrodes.

Torsion scale with a weighing error of no more than 0.001 g.

Laboratory scales of the 2nd accuracy class according to GOST 24104*.
______________
* On the territory of the Russian Federation GOST 24104−2001. — Note the manufacturer’s database.

Graphite powder of high purity according to GOST 23463.

Nitric acid of high purity according to GOST 11125, a solution of 1:2.

Sulfuric acid of high purity according to GOST 14262, solution 1:1.

Ammonium chronologicly according to GOST 3774.

Distilled water according to GOST 6709 and reagents qualification not lower than h.d. a.

Developer metalhydrogen consisting of two solutions which, before manifestation, are mixed in the ratio 1:2.

State standard samples N 1591−79−1594−79; 1595−79−1598−79; 1599−79−1602−79. Allowed to use for constructing the calibration graphs similar to the composition of the samples comparison.

Samples of comparison for the determination of chromium.

Prepared on the basis of sulphate of lead derived from lead brands S00 (GOST 22861) as follows: 30−40 g of lead dissolved in 120−150 cmof nitric acid solution. When white precipitate add water until it dissolves. The lead sulfate is precipitated by gradual addition of 150−180 cmof sulfuric acid solution. The solution above the precipitate is drained and discarded. The precipitate is washed twice with 100−130 cmof water, acidified with 1−2 cmof solution of nitric acid, dried and calcined in a muffle furnace at a temperature of ~550 °C for 30 min. Sulphate of lead is stored in a plastic jar.

The basic sample containing 0.01% chromium in the calculation of the lead, is prepared by depositing 14,637 g of the base 1 cmof a solution of chrome containing 1 mg chromium 1 cm, which is prepared by dissolving of 98.1 mg chromological ammonia in the water. The solution was transferred to a volumetric flask with a capacity of 50 cm, add 1 cmof nitric acid solution and adjusted with water to the mark on the flask.

Working samples comparison get when diluted basis basic sample 10 times, and each newly prepared sample in 2−2,5 times. The recommended mass fraction of chromium in the samples comparison: 1·10; 5·10; 2,5·10; 1·10; 5·10% .

References prepared according to these methods, every company must be certified as a SOP in the prescribed manner.

Samples of comparison: the basis for the preparation of samples of comparison is the lead brand of S00 according to GOST 22861, clean-defined elements. Impurities and ligature alloys is administered in the form of metals. Actual grades and the samples of the comparison is melted in crucibles at a temperature of 500−600 °C.

Method serial dilutions of each sample is again fused the basis of the prepared three series of samples comparison:

for the determination of bismuth, silver and copper;

for the determination of sodium, calcium and magnesium;

for the determination of antimony, arsenic, tin, and zinc.

Each melt was thoroughly stirred and poured into a mold.

For analysis and the preparation of solutions of reagents used distilled water according to GOST 6709 and reagents qualification not lower than h.d. a.

Samples of comparison for the determination of iron.

Prepared on the basis of oxide, lead brand S000 (GOST 22861) as follows: 30−40 g of lead dissolved in 120−150 cmof nitric acid solution. When white precipitate add water until it dissolves. The solution was evaporated, the residue dried and calcined in a muffle furnace at a temperature of 600 °C for 1 h. the lead Oxide is stored in a plastic container.

The main sample, containing 0,006% of iron in terms of lead, is prepared by depositing 16,158 g fundamentals of 0.9 cmof a solution of iron, containing 1 mg of iron per 1 cm, which is prepared by dissolving 100 mg of iron, reduced hydrogen in the nitric acid solution diluted 1:1. The solution was transferred to a volumetric flask with a capacity of 100 cmand adjusted to the mark with water. Working samples of the comparison obtained by dilution of the main sample in 1.5 and every newly prepared in 2 times. The recommended mass fraction of iron in the samples comparison: 6·10; 4·10; 2·10; 1·10; 5·10%.

The comparison samples, prepared on each enterprise must be certified as a SOP in the prescribed manner.

Note. Nitric acid and distilled water, used in the determination of iron, must be double-distilled.

Allowed the use of devices with photoelectric registration of spectrum and other spectrographic equipment and facilities other materials and reagents, generating accuracy metrics defined in this standard.


(Changed edition, Rev. N 1, 2, 3).

3. ANALYSIS

3.1. Determination of bismuth, silver and copper

As excitation sources use spark generator IG-3 included a complex scheme.

The current in the primary circuit of the transformer 2 And the auxiliary spark gap 3 mm, the analytical gap of 2.5 mm, — inductance of 0.55 mH, a capacitance of 0.01 UF.

The spectra are photographed on photographic plates «spectrographic» type 2 through a three-stage attenuator installed in front of the slit of prism spectrograph.

For analysis use the following line, nm

State standard samples and the samples sharpened with a file to «plane.» Allowed sharpening of electrodes a file «on the roof» with the width of the pad 2−3 mm.

As a counter use of the spectral-pure carbon rod, sharpened to a cone with an area of 1.5−2.0 mm.

(Changed edition, Rev. N 1, 2).

3.2. Determination of sodium, calcium, magnesium, arsenic, antimony, tin and zinc

Samples and standard samples are crushed with a file in sawdust, ofmagnesium and fill in the crater, the lower carbon electrode-anode with a depth and a diameter of 3 mm when determining the content of sodium, calcium, magnesium and zinc, with a depth of 5 mm and a diameter of 4 mm at determination of arsenic, antimony, and tin.

The upper electrode is a carbon rod sharpened to a truncated cone with ground diameter of 1.5−2 mm. excitation spectra of the arc either AC or DC power 16 And in the determination of calcium, sodium, magnesium and zinc, arc, AC power 16 And in the determination of arsenic, antimony and tin.

In the determination of arsenic, antimony and tin spectra are photographed on photographic plates of types 2, UFS-3, SFC-02 type spectrograph STE-1 in the determination of magnesium, zinc — plate types 1 or PFS-02 and the determination of the sodium and calcium — plate type «panchrom» type spectrograph ISP-30.

Front slit prism spectrograph establish a three-tier reliever. The exposure time when determining the zinc — 40, other elements to complete combustion of the sample.

To construct the calibration curve using the following analytical lines, nm:

(Changed edition, Rev. N 1, 2, 3).

3.3. (Deleted, Rev. N 1).

3.4. Determination of chromium

A sample weighing 1 g is dissolved in 30 cmof a solution of nitric acid under heating. When the deposition of a top up of 5−10 cmof water until it dissolves. Then slowly pour 6 cmof sulfuric acid solution. The solution above the precipitate was evaporated under an infrared lamp, dry it on the hotplate and calcined in a muffle furnace at a temperature of ~550 °C for 30 min.

Prepared samples and the comparison samples are mixed with graphite powder in a ratio of 7:1 and placed in carbon electrodes of high purity with the size of the crater in a 4x4 mm, pre-baked in the arc of DC power 12 And for 10 s.

The spectra are photographed on the photographic plates of the type 2-type spectrograph DFS-8 in the first order in the arc of a DC power of 15 A. the exposure Time of ~2 min (until complete burnout of the sample 10 C).

To construct the calibration curve using the analytical line of chrome 302,1 nm and as part of the background to the left of the line.

(Changed edition, Rev. N 3).

3.5. Determination of iron content

A sample weighing 2 g was dissolved in 30−40 cmof nitric acid when heated. The solution was evaporated, the residue dried and calcined in a muffle furnace at a temperature of 600 °C for 30 min.

Prepared samples and the comparison samples placed in the graphite electrodes of high purity with a crater size of 3x3 mm.

The spectra are photographed on the type of spectrograph ISP-30 in the arc of an alternating current power 16 And the photographic plates of types 1 or PFS-02. The exposure time of 2 min (until complete burnout +10).

To construct the calibration curve using the analytical line of iron 271,9 or 302,0 nm and as part of the background.

(Added, Rev. N 3).

4. PROCESSING OF THE RESULTS

4.1. Spectra of samples comparison (SOG or SOP) is photographed on each plate three times, the spectra of the analyzed samples six times. With microphotometer measure the blackening of analytical lines of the determined elements, lines of comparison and the nearby background (in the determination of the mass fraction of arsenic, antimony, tin, iron and chromium).

Calibration graphs constructed in the coordinates , in the determination of calcium, magnesium, zinc, sodium, iron and chromium, where the difference pucherani lines of impurities and the main substances;  — mass fraction of the element in the samples comparison, %.

Graded graphs constructed in the coordinates , in the determination of arsenic, antimony and tin, where the intensity of the impurity lines;  — the intensity of the line comparison.

Find and using the characteristic curve of photographic plates.

Using the known values or on schedule find the mass percent of defined impurities.

The final result of the analysis be the arithmetic mean of results of two parallel measurements obtained on the same photographic plate (each simultaneous determination of three spectrogram

mm).

4.2. The maximum discrepancy between the results of two parallel measurements () and the results of two tests (), calculated with the confidence probability =0,95, shall not exceed the values calculated by the formulas:

in the determination of silver in the range of mass fraction from 0.002 to 0.004%;

in the determination of copper, bismuth, zinc, antimony, arsenic, tin, sodium, calcium, magnesium, chromium, silver and iron, where is the arithmetic mean of the results of two parallel measurements; in the determination of silver in the range of mass fraction from 0.002 to 0.004%;

in the determination of copper, bismuth, zinc, antimony, arsenic, tin, sodium, calcium, magnesium, chromium, silver and iron; where  — average of the two results of the analysis.

Numerical values of the permissible differences are rounded to numbers with one significant figure.

The numerical values of the results of the analysis should end with the figure of the same category as the values of the corresponding allowable differences.

(Changed edition, Rev. N 3).

5. THE CONTROL OF CORRECTNESS OF ANALYSIS RESULTS

5.1. Control of correctness of the analysis is carried out according to GOST 25086периодически — at least once a month and each time the repair and replacement of devices after long breaks in operation, after replacement of samples comparisons and other changes that affect the result of the analysis.

(Changed edition, Rev. N 3).