GOST 13637.1-93

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  ГОСТ 13637.1-93

GOST 13637.1−93 Gallium. Atomic-emission method for the determination of aluminium, bismuth, iron, silicon, magnesium, manganese, copper, Nickel, tin, lead, chromium and zinc

GOST 13637.1−93

Group B59

INTERSTATE STANDARD

GALLIUM

Atomic-emission method for the determination of aluminium, bismuth, iron,
silicon, magnesium, manganese, copper, Nickel, tin, lead, chromium and zinc

Gallium. Atomic-emission method for the determination of aluminium,
iron, bismuth, silicon, magnesium, manganese, copper, nickel, tin,
lead, chromium and zinc

AXTU 1709

Date of introduction 1995−01−01

Preface

1. DEVELOPED by the Interstate technical Committee 104 «of the Semiconductor and rare metals products. Especially pure metals», State Institute of rare metals (Giredmet)

INTRODUCED by Gosstandart of Russia

2. ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 4−93 of 19 October 1993)

The adoption voted:

3. Resolution of the Committee of the Russian Federation for standardization, Metrology and certification from 02.06.94 N 160 inter-state standard GOST 13637.1−93 introduced directly as state standard of the Russian Federation from 01.01.95

4. REPLACE GOST 13637.1−77

INFORMATION DATA

REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies a direct atomic emission method for the determination of mass fractions of impurities in Gaul:

The method is based on measuring the intensity of the lines of the elements of the impurities in the spectrum obtained by evaporation of gallium with powdered graphite from the channel of the graphite anode in the arc DC.

Mass fraction of impurities in Gaul determined by calibration graphs constructed in the coordinates: logarithm of ratio of intensity of lines of the designated element to the background intensity () is the logarithm of the mass fraction of the element ().

1. GENERAL REQUIREMENTS

General requirements for method of analysis and security requirements — according to GOST 13637.0.

2. APPARATUS, MATERIALS AND REAGENTS

The diffraction type spectrograph DFS-8 or similar type with the grating of 600 lines/mm and being light.

The arc generator type DG-2 with an additional resistor or a generator of a similar type, adapted to ignite the DC arc high frequency discharge.

Rectifier 250−300, 30−50 A.

Microphotometer type MF-2 or similar type.

Spectromancer of PS-18 or similar type.

Laboratory scales of the 1st class according to GOST 24104*.
_______________
* On the territory of the Russian Federation GOST 24104−2001. — Note the manufacturer’s database.

Libra torsion bar type W with capacity up to 500 mg Libra or similar.

Mortar and pestle made of organic glass.

Box of organic glass.

Muffle furnace with thermostat for temperatures up to 900 °C.

Platinum crucibles N 6 with lids.

Grinding machine graphite electrodes.

Graphite electrodes, machined from high purity graphite rods-7−3 6 mm in diameter, sharpened to a cone with an apex angle of 15 degrees and with a platform with a diameter of 1.5 mm at the tip, burnt in the arc of direct current at 15 And during 15 s.

Graphite electrodes, machined from high purity graphite rods-7−3 6 mm in diameter, with a channel depth of 5 mm and a diameter of 4 mm, annealed in the arc of direct current at 15 And during 15 s.

Cleaning firing is subjected to each pair of electrodes before measurement (electrode, sharpened to a cone — cathode, the electrode with the channel / anode).

Graphite powder of high purity according to GOST 23463.

Aluminum oxide anhydrous for atomic emission analysis.

Bismuth oxide according to GOST 10216.

Iron oxide.

Silicon dioxide according to GOST 9428.

Magnesium oxide according to GOST 4526.

Manganese dioxide anhydrous OS. h-9−2.

Copper oxide according to GOST 16539, powdery.

Nickel oxide black GOST 4331.

Tin oxide according to GOST 22516.

Of lead oxide.

The chromium oxide according to GOST 2912, metallurgical, brand OC-O.

Zinc oxide according to GOST 10262.

Gallium, net-defined impurities, prepared as specified in GOST 13637.0.

Photographic plate for spectrographic type SFC-02 production of Pereslavl «Slavich» size 13x18 or 9x12 cm, or equivalent, providing normal blackening of analytical lines and the surrounding background in the spectrum.

Developer:

Lamp infrared ikz-500 with the voltage regulator RNO-250−0,5 or similar.

The technical rectified ethyl alcohol according to GOST 18300, nederevyannyy and double-distilled in quartz apparatus.

State standard samples (GSO) powder graphite SPG-27 PR GEO 2820−83, diluted powder graphite five times in a mortar made of organic glass were placed 1 g of GSO, add 4 g of powdered graphite and carefully grind the mixture with ethanol for 50 min, and then dried under an infrared lamp.

3. PREPARATION FOR ASSAY

3.1. Sample preparation comparison (OS)

Each comparison sample is prepared immediately before the photographing of the spectrum, placing into the channel of the graphite electrode 20 mg of the sample in comparison to graphite powder (OSGP) and 20 mg gallium, net-defined impurities. In terms of the method in accordance with the ratio of the masses of miscible substances, the mass fraction of impurities in OS (calculated as mass fraction of admixtures in Gaul) is equal to the mass fraction of the impurities in OSGP.

3.2. Sample preparation comparison, graphite powder (OSGP).

Prepare the basic pattern of comparison for powdered graphite (OOGP) containing 1% of aluminium, bismuth, iron, silicon, magnesium, manganese, copper, Nickel, tin, lead, chromium and zinc and 88% of carbon, based on the contents of metal and carbon in mixtures of metals and carbon, mechanically mixing graphite powder with oxides of the respective metals.

Before taking the test portions of the silicon dioxide and magnesium oxide placed in a crucible, calcined in a muffle furnace at 700−800 °C for 30 min and cooled in a desiccator.

Hitch weight 0,0189 g of anhydrous aluminum oxide, 0,0111 g of bismuth oxide, 0,0143 g of iron oxide, to 0, 0214 g of silicon dioxide, 0,0166 g of magnesium oxide, 0,0158 g of manganese oxide, anhydrous IV, 0.0125 g of copper oxide, 0,0141 g of Nickel oxide black, 0,0127 g of tin dioxide, 0,0108 g of lead oxide, 0,0146 g of chromium oxide, 0,0124 g of zinc oxide was placed in a mortar made of organic glass and add 0,8800 g of powdered graphite. The mixture is thoroughly triturated with ethyl alcohol for 50 min and dried under an infrared lamp.

In order to avoid impurities grinding in a mortar, and drying under a heat lamp are in the box of organic glass.

AOGP also allowed to cook by introducing the designated elements in the form of solutions, as specified in GOST 13637.3.

ОСГП1-ОСГП10 prepare serial dilution OOGP, and then each subsequent sample is powdered graphite.

The mass fraction of each of the designated impurities in ОСГП1-ОСГП10 (percentage in the calculation of the mass fraction of the metal in mixtures of metals and carbon) and added to the mixture of sample powder of graphite and diluted sample, mixing for this sample are given in table.1.

Table 1

Listed in the table.1 sample of powdered graphite and diluted sample was placed in a mortar made of organic glass, carefully triturated with ethyl alcohol for 30 min and dried under an infrared lamp. For ОСГП6-ОСГП10 use ethanol, double-distilled in quartz apparatus. Grinding in a mortar, and drying under a heat lamp are in the box of organic glass.

The analysis used ОСГП1-ОСГП10.

OOGP, ОСГП1-ОСГП10 stored in tightly closed cans of organic glass.

4. ANALYSIS

When recording the spectrum of the sample in the channel of the graphite electrode with a diameter of 4 mm and a depth of 5 mm is consistently placed 20 mg of graphite powder and 20 mg of gallium analyzed pieces no larger than 3 mm in diameter (in order to avoid introducing contaminants to the sample of gallium is ground without removing the crystallized plate from a plastic bag).

When taking the spectrum of each reference sample into a channel of the same graphite electrode sequentially placed 20 mg of the sample in comparison to graphite powder and 20 mg gallium, net-defined impurities, pieces not larger than 3 mm in diameter.

The lower electrode with the sample (or reference sample) is an anode, the upper, sharpened on a cone — cathode. Between the electrodes ignite the arc DC power 15 A and the photographing range of exposure of about 3 minutes (to complete combustion). The distance between the electrodes during the exposure is maintained at 3 mm.

Spectra in the region of wavelengths of 240−340 nm photographed with the spectrograph of the DFS-8 with a grating of 600 lines/mm operating in the first order with being a condenser and the intermediate aperture 5 mm. the Width of the slit of a spectrograph 15 microns. In the cassette spectrograph charge record type SFC-02. The spectrum of each sample and each sample of the comparison register on the photographic plate three times. In addition, on the same plate thrice photographing range bases of comparison samples, wherein the channel electrode is placed sequentially each time 20 mg of graphite powder and 20 mg gallium, net-defined impurities.

Exposed photographic plates show washed with water, fixed, washed in running water for 15 min and dried.

5. PROCESSING OF THE RESULTS

5.1. In each spectrogram photometric blackening of analytical lines of the designated element (see table.2) and nearby background (minimum blackening near the analytical line of the element on either side, but with the same side in all the spectra taken on one disc) and calculate the difference pucherani .

Table 2

Three parallel values , , obtained three spectrograms taken for each sample, find the arithmetic mean of the results .

According to the obtained average values found in the tables of mandatory application values .

5.2. If the analytical line of the designated element in the spectra of samples basis of comparison is missing, using the values and for samples comparison, build a calibration curve in the coordinates , . On this chart, the value for the sample determine the mass percent of impurities in the sample.

5.3. Permissible discrepancies in the results of three parallel measurements (the ratio of largest to smallest) and two results of the analysis (the ratio of largest to smallest) are shown in table.3.

Table 3

Permitted discrepancies for the intermediate mass fraction calculated using linear interpolation.

5.4. If in the spectra of samples basis of comparison, there is a weak line of the element, then the construction of calibration curve in the coordinates (, ), corrected for the mass fraction of the element in the sample comparisons. An amendment is permissible only if the mass fraction of the element in the sample comparison does not exceed the specified for the method lower limit of the interval defined by the mass fraction. If this condition is not met, it is necessary to choose for the basis of comparison samples a cleaner at the designated impurities gallium or graphite powder and phased perform a thorough cleaning of the premises, jobs, used equipment, reagents and materials.

After receiving the adjusted calibration curve calculation of the mass fraction of impurities is carried out as specified in the PP.5.2, 5.3.

5.5. Control of the correctness of the analysis performed according to GOST 13637.0 or in the presence of state standard samples (GSO) powder graphite SPG-27 PR GEO 2820−83 in the following way. In the channels of three graphite electrodes with a diameter of 4 mm and depth 5 mm administered at 20 mg metallic gallium, pure at the designated impurities, and 20 mg diluted GEO.

Analysis of the mixture is carried out simultaneously with the analysis of samples for PP.4 and 5. For each impurity, calculate the ratio of the greater to the lesser of the two quantities as the result of the analysis of the obtained mixture diluted GSO and 0.2 certified values of mass fractions of impurities in GSO. The results of the analysis of samples I think is right with confidence probability of 0.95, if the ratio is , where  — is regulated in paragraph 5.3, the permissible discrepancy of the two results of the analysis of the sample of gallium, with a mass fraction of impurities is equal to the result of analysis of a mixture of gallium with a dilute GEO.

APP (mandatory). Table of values of a ratio of intensity of lines of the designated element to the background intensity

APP
Mandatory

Table greatness , the respective measured values .

The tables below are used to transfer measured values and values .

The tables contain the results of the calculation according to the formula

.

We denote the total intensity of the line with background through , the intensity of the background under the high line in the absence of a line through . Since , the ratio of intensity to background intensity is determined by the expression .

If the conditions of photographing the spectrum chosen so that the blackening of a line with a background and background in the absence of the line lie in the normal region, where ;  — contrast ratio. Hence, using the expression derived .

The tables include most important to the practice of analytical work values from 0.05 to 1.99.

The construction of the table is divided into two parts:

part of the covering values from 0.05 to 0,999, part of the covering values from 1.00 to 1.99.

Consider the first part of the table .

In the first column on the left under the bold printed values 0,05; 0,06; 0,07 0,99… The right of the sign in column headers in bold printed numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, representing the third after the decimal point, the sign of the value .

Having a certain value , for example 0,537, find the line of 0.53 corresponding to the first two decimal places, and column number 7 to read the corresponding value 0,388. Similarly, for 0,143; in the line of 0.14 in column number 3 read the appropriate value

.

The second part of the table, covering values from 1.00 to 1.99, built in a similar way, with the difference that in the first left column, the value is shown with one decimal place, and the bold printed numbers 0, 1, 2, 3…9 in the column headers represent the second after the decimal point, the sign of the value.

So, having a value of 1.36, in the line of 1.3 in the column with the number 6 read 1,341.

For values smaller than had 0.301, the characteristic is negative, which is denoted by a minus sign over the characteristic (…).

Since , then tables can be used to find values corresponding to values in any method of measurement.

If the contrast ratio is not measured, instead of the values in table enter quantities . So, if in this case, the measured value and 0.674, the string value of 0.67 in column 4 read response 0,571. It should be noted that the found thus the value of (0,571) represents not a . The precision of the analysis by the method of «three standards» the fact is almost no effect.

Table 4

Values corresponding to measured values