GOST 26239.3-84
GOST 26239.3−84 semiconductor Silicon, the starting materials for its production and quartz. Methods for determination of phosphorus (Change No. 1)
GOST 26239.3−84
Group B59
STATE STANDARD OF THE USSR
SEMICONDUCTOR SILICON, THE STARTING MATERIALS FOR ITS PRODUCTION AND QUARTZ
Methods for determination of phosphorus
Semiconductor silicon, raw materials for its production and quartz. Methods of phosphorus determination
AXTU 1709
Valid from 01.01.86
to 01.01.91*
_______________________________
* Expiration removed
Protocol N 7−95 Interstate Council
for standardization, Metrology and certification
(IUS N 11, 1995). — Note the manufacturer’s database.
DEVELOPED by the Ministry of nonferrous metallurgy of the USSR
PERFORMERS
Y. A. Karpov, M. N. Schulepnikov, M. K. Vinnikov, G. G., Gavin, N. Gradskova, O. V. Zavialov, T. I. Zyablova, V. E., Quinn, V. A. Krylov, A. I. Kuzovlev, N. And. Marunya, V. G., Miscreants, V. M. Mikhailov, M. G. Nazarova, V. A. Orlov, A. I. Stepanov, N. With. Sysoeva, V. I. Firsov, G. I. Alexandrova
INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
Member Of The Board Of A. P. Snurnikov
APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on standards dated July 13, 1984 N 2490
The Change N 1, approved and in effect
Change No. 1 made by the manufacturer of the database in the text ICS N 10, 1990
This standard specifies the extraction-photometric method for the determination of phosphorus from 2·10to 2·10
% in technical silicon, extraction-colorimetric method for the determination of phosphorus is from 1·10
to 5·10
% trichlorosilane and silicon tetrachloride and from 4·10
to 1·10
% silicon dioxide (synthetic quartz); neutron-activation method for the determination of phosphorus is from 1·10
to 1·10
% in semiconductor silicon.
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 26239.0−84.
2. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF PHOSPHORUS
The method is based on dissolving of silicon with a mixture of hydrofluoric and nitric acids in the presence of potassium permanganate, the removal of the bulk silicon transport in the form of fluoride, a selective concentration of phosphorus with a mixture of butanol with chloroform and subsequent photometric determination of phosphorus in the form of restored molybdophosphoric of heteroalicyclic.
2.1. Apparatus, reagents and solutions
Photoelectrocolorimeter FEK-56 or similar device.
Tile electric.
Analytical scale.
Measuring cylinders with a capacity of 5 and 10 cm.
Volumetric flasks with a capacity of 25 and 100 cm.
Separating funnel with a capacity of 50 cm.
Conical funnel with a diameter of 30 mm.
Micropipettes with a capacity of 1 and 5 cm.
Tweezers Teflon or plastic. The paper filter «red ribbon» with a diameter of 70 mm.
Crucibles of glassy carbon with a capacity of 50 cm.
Autoclave analytical With 3103 in accordance with the drawing app with the reaction cups made of PTFE with a capacity of 2 and 30 cmor 3551 with a camera to concentrate With 3552 in accordance with the Annex to GOST 26239.1−84 or similar. When working with the autoclaves should comply strictly with the attached instruction manual.
Drying Cabinet, providing a heating temperature of 250 °C.
The fan room.
Nitric acid of high purity according to GOST 11125−84 density of 1.4 g/cmand diluted 1:1.
Hydrochloric acid of high purity according to GOST 14261−77, OS.h. 21−4, a density of 1.19 g/cm.
Hydrofluoric acid OS.h. 27−5, density 1.2 g/cm.
Sodium molybdate according to GOST 10931−74, 0.4 M (8,6% solution).
Glycerin according to GOST 6259−75.
Tin dichloride 2-water on the other 6−09−5384−88, h, 10% solution in glycerol.
Potassium permanganate according to GOST 20490−75, 10% solution.
Normal butyl alcohol (-butanol) according to GOST 6006−78 distilled.
Chloroform technical according to GOST 20015−74*, distilled.
______________
* On the territory of the Russian Federation the document is not valid. Standards 20015−88. — Note the manufacturer’s database.
The mixture for the extraction of phosphorus: 30 cm-butanol are mixed with 70 cm
of chloroform.
Potassium phosphate according to GOST odnosemjannyj 4198−75.
The standard solutions of phosphorus (V).
Solution a containing 0.1 mg of phosphorus (V) 1 cm; 0,439 g of single potassium phosphate is dissolved in water, and dilute with water to 1000 cm
.
Solution B containing 0.01 mg of phosphorus (V) 1 cmprepared on the day of use by dilution of a standard solution And with water 10 times.
(Changed edition, Rev. N 1).
2.2. Analysis
2.2.1. Dissolution of a test portion in an open system
The weight and mass of 0.05−0.25 g was placed in a crucible of glassy carbon, poured two drops of potassium permanganate, 5 cmhydrofluoric acid, mix. Then gently, to prevent violent reaction, dropwise introduced 1 cm
of nitric acid (1:1), using periodic heating to complete dissolution of the sample.
2.2.2. Dissolution of the sample in the analytical autoclave
The weight and mass of 0.05−0.25 g were placed in Teflon beaker with a capacity of 2 cm, add two drops of solution of potassium permanganate. In the reaction Teflon beaker with a capacity of 30 cm
pour 5 cm
hydrofluoric and 1 cm
of nitric (diluted 1:1) acids, gently with tweezers dipped a glass with a capacity of 2 cm
into a glass with a capacity of 30 cm
, which is closed with a lid and placed in the autoclave.
The autoclave is closed and overturned twice, after 5 min, the inversion is repeated; after 10 minutes, the autoclave was placed in a preheated drying Cabinet, heated at 180 °C for 25 min, removed from oven and cooled with a fan to room temperature. The open autoclave, a solution of fluoropolymer in the reaction Cup was transferred to a crucible of glassy carbon, washing the walls with water and add two drops of solution of potassium permanganate.
For sample preparation of multiple batches simultaneously in a single hermetically closed space is used With autoclave 3551 with the camera to concentrate With 3552.
Into the chamber for concentrating pour 35 cmphotoreactivation and 5 cm
of nitric acid. In three of the reaction containers placed PTFE sample sample mass of 0.25 g, is added to each suspension, two drops of solution of potassium permanganate and 0.5 cm
hydrofluoric acid. The camera focus close lid with a holder for reaction vessels. Camera sealed in a metal housing of the analytical autoclave. The autoclave was placed in a preheated drying Cabinet and kept at a temperature of 180 °C for 2 h, removed from oven and cooled with a fan or bottom of the refrigerator to room temperature. Open the autoclave, remove the camera and wipe the outside with a cotton swab moistened with alcohol. The dry residue obtained in Teflon reaction vessel is dissolved in 1.5 cm
of concentrated hydrochloric acid and 3.5 cm
of water, the solution transferred to a separatory funnel. Next, carry out analysis as specified in claim
(Changed edition, Rev. N 1).
2.2.3. Determination of phosphorus
2.2.3.1. The solution obtained according to claim 2.2.1 or claim 2.2.2, is evaporated on the tile, and then to dryness in a water bath, add 5 cmhydrofluoric acid and again evaporated to dryness. The dry residue is treated with 2 cm
of concentrated hydrochloric acid and evaporated in a water bath to dryness.
To the dry residue poured 1.5 cmof concentrated hydrochloric acid, 3.5 cm
of water, the solution transferred to a separatory funnel, pour 5 cm
of 0.4 M solution of sodium molybdate and 10 cm
of a mixture
of butanol with chloroform, extracted molybdophosphoric the heteropolyacid, shaking the solution for 2 min. Organic phase (lower layer) containing the heteropolyacid molybdophosphate, filtered through a paper filter into a volumetric flask with a capacity of 25 cm
, the volume was adjusted to the mark with a mixture
of butanol with chloroform, is added one drop of a solution of tin dichloride and mix thoroughly. Measure the optical density of the extract on photoelectrocolorimeter at 630 nm against the mixture
-butanol with chloroform, using cuvettes for photometry with the optical path length of 50 mm. the phosphorus Content determined by the calibration schedule. In parallel spend control experience on the phosphorus content in the reagents through all stages of the analysis and introduced into the obtained results corresponding wher
internals.
2.2.3.2. Construction of calibration curve
In a separating funnel with a capacity of 50 cmpour of 0.05 and 1.05 cm
standard solution of phosphorus was Used with an interval of 0.2 cm
, poured 1.5 cm
of concentrated hydrochloric acid, and 3.5 cm
water, 5 cm
of 0.4 M solution of sodium molybdate and 10 cm
of a mixture
of butanol with chloroform. Next, carry out analysis as specified in claim
Build a calibration graph of optical density on concentration, used to determine the phosphorus concentration in the analyzed samples
E.
2.3. Processing of the results
2.3.1. Mass fraction of phosphorus () in percent is calculated by the formula
where is the mass of phosphorus was found in the calibration schedule, mcg;
— the weight of the portion,
For the results analysis be the arithmetic mean of two parallel definitions, drawn from separate batches.
2.3.2. The difference between the larger and the smaller of the two results of parallel measurements with a confidence probability of 0.95 does not exceed the allowable absolute values of the differences of parallel measurements, are given in table.1.
Table 1
| Mass fraction of phosphorus, % | The absolute allowable difference, % |
2·10 |
1·10 |
5·10 |
2·10 |
1·10 |
3·10 |
5·10 |
1·10 |
1·10 |
2·10 |
2·10 |
4·10 |
Permitted discrepancies for the intermediate grades are calculated using linear interpolation.
2.3.3. To verify the correctness of the analysis using the method of additives. Two sample one of the samples analysed is dissolved according to claim 2.2.1 or claim ), calculated by the formula
(where (is the result of the analysis of the sample, %;
— the mass of phosphorus in the added volume of the working solution phosphorus, mg) was not more than the upper limit of the interval defined by the mass fraction of phosphorus (see table.1) and at least tripled the value of the lower bound of this interval.
Analysis think is right with confidence probability of 0.95, if the result of analysis of sample with additive, differs from
by no more than
is the absolute maximum discrepancy between the results of two parallel measurements of phosphorus in the sample without additives, %;
— the permissible discrepancy of the two results of parallel measurements of phosphorus in the same sample without additive, %.
3. EXTRACTION-COLORIMETRIC METHOD FOR THE DETERMINATION OF PHOSPHORUS
The method is based on the separation of silicon transport in the form of fluoride and the colorimetric determination of phosphorus in restored molybdophosphoric the heteropolyacid in the extract of methyl isobutyl ketone with butyl acetate.
3.1. Apparatus, reagents and solutions
The drying oven of the type LP-301 or similar with a thermostat temperature up to 250 °C.
Tile electrical with closed spiral with a capacity of 600 watts.
Fan room or similar.
Refrigerator.
Autoclave analytical М167 with the reaction beaker with a capacity of 70 cmor similar.
Autoclave analytical With 3294 with the reaction cups with a capacity of 30 and 250 cm.
Cylinders for colorimetrically with ground stoppers with a capacity of 5 cm, length 150 mm, diameter 6 mm.
Microburette with a capacity of 5 cm.
Micropipettes with a capacity of 1 and 5 cm.
Plastic piston pipettes with a capacity of 5 and 10 cm.
Glass piston pipettes with a capacity of 1 cm.
Measuring cylinders with a capacity of 5 and 10 cm.
Tweezers Teflon or plastic.
The filter paper «red tape».
Crucibles of glassy carbon with a capacity of 100 cm.
Hydrofluoric acid OS.H.27−5, density 1.2 g/cm.
Nitric acid of high purity according to GOST 11125−84, density 1.4 g/cm, distilled.
Hydrochloric acid of high purity according to GOST 14261−77, OS.H.21−4, a density of 1.19 g/cm.
Potassium permanganate according to GOST 20490−75, 10% solution.
Ammonium molybdate according to GOST 3765−78, 4% solution.
Potassium armanavicius a 0.3% solution.
Ascorbic acid food OS.CH., 0.1 M solution of 1.76 g of ascorbic acid dissolved in 100 cmof water.
Potassium phosphate according to GOST odnosemjannyj 4198−75, H. h
The mixture of reagents prepared before use by mixing 10 cmof hydrochloric acid, 6 cm
of ammonium molybdate, 12 cm
of ascorbic acid and 2 cm
of potassium Armenonville.
Butyl ether of acetic acid (butyl acetate), part distilled.
Methyl isobutyl ketone, h, distilled.
The mixture for the extraction is prepared by mixing equal volumes of butyl acetate with methyl isobutyl ketone.
The standard solutions of phosphorus.
The alternate solution containing 0.1 mg of phosphorus in 1 cm: 0,438 g of single potassium phosphate is dissolved in water, and dilute with water to 1000 cm
.
The working solution containing 0.001 mg of phosphorus in 1 cm: prepared on the day of use by diluting the solution 100 times spare.
(Changed edition, Rev. N 1).
3.2. Preparation for assay
3.2.1. Cooking scales standard extracts
In cylinders for colorimetrically using a micropipette make 0,00; 0,02; 0,05; 0,10; 0,15; 0,20; 0,25; 0,30; 0,35; 0,40; 0,45; 0,50 cmstandard working solution of phosphorus, which corresponds to 0,00; 0,02; 0,05; 0,10; 0,15; 0,20; 0,25; 0,30; 0,35; 0,40; 0,45 and 0.50 µg of phosphorus. The volume of the solution was adjusted with microburette water to 2.64 cm
, flow of 0.36 cm
of a mixture of reagent and after 3 min 0.3 cm
mixture for extraction of molybdophosphoric heteroalicyclic. The cylinders are stoppered and shaken five times. After 5 minutes the scale of standard extracts used to estimate the concentration of phosphorus in the sample solution.
(Changed edition, Rev. N 1).
3.3. Analysis
A sample mass of 20 g of trichlorosilane (15 cm) or silicon tetrachloride (13 cm
) was placed in Teflon beaker With 3294 autoclave with a capacity of 30 cm
; the beaker is immersed in a beaker with a capacity of 250 cm
, 25 cm containing
hydrofluoric acid, 15 cm
water and 1 cm
of nitric acid. The autoclave was closed, inverted and placed in the refrigerator. After 30 min the sample solution from the reaction Cup of the autoclave are transferred into a glassy carbon crucible.
Instead of the autoclave dissolution of the chlorides of silicon allowed the use of dissolution in an open system in determining of phosphorus from 2·10% masses: 7 cm
water and 1 cm
of nitric acid was placed in a glassy carbon crucible and cooled with dry ice, then 10 g of trichlorosilane (7.5 cm
) or silicon tetrachloride (6.5 cm
) was carefully poured into water while stirring. After the reaction, the contents of the crucible are dissolved in 10 cm
hydrofluoric acid.
After dissolution of sample sample content a glassy carbon crucible is evaporated first on the tile, and then in a water bath to dryness.
A sample weighing 5 g was placed in the reaction beaker with a capacity of 70 cmautoclave M 167, pour 20 cm
hydrofluoric and 1 cm
of nitric acid, a glass lid and placed in an autoclave analytical M 167. Close the autoclave, put into an oven and incubated for 2−3 hours at 180−200 °C. Then the autoclave is removed from the oven, cooled with a fan or refrigerator. After 30 min the sample solution from the reaction Cup of the autoclave are transferred into a glassy carbon crucible and evaporated to dryness first on a tile and then in a water bath.
In determining of phosphorus from 1·10% by weight and above for the dissolution of two batches of samples weighing 2 g use analytical autoclave With 3551 with the camera to concentrate With 3552:
in the chamber for concentration 35 cm pourhydrofluoric and 5 cm
of nitric acid. Two PTFE reaction container is placed a sample of sample weight of 2 g. all reaction PTFE capacity adds 2 cm
hydrofluoric acid and two drops of solution of potassium permanganate. The camera focus close lid with a holder for reaction vessels. Camera sealed in a metal enclosure of the autoclave. The autoclave was placed in a preheated drying Cabinet and kept at a temperature of 180−200 °C for 2−3 hours, removed from oven and cooled with a fan or bottom of the refrigerator. Open the autoclave, remove the camera, open the lid, the fluoropolymer solution from each reaction vessel are transferred into a glassy carbon crucible, is evaporated on the tile, and then in a water bath to dryness. Get two of the concentrate samples and two concentrate control experience.
Instead of the autoclave dissolution of synthetic quartz allowed the use of dissolution in an open system in the determination of phosphorus is from 1·10% mass:
Concreteras 2 g samples placed in a glassy carbon crucible and was dissolved with heating in 20 cmhydrofluoric and 1 cm
of nitric acid, cover the crucible with a lid. The solution is evaporated on a hot plate and then in a water bath to dryness.
To the dry residue obtained according to claim.3.3.1 and 3.3.2, poured on a 2.64 cmof water and 0.36 cm
of a mixture of reagents. After 3 min the solution was transferred to a cylinder for colorimetrically administered 0.3 cm
mixture for extraction of molybdophosphoric heteroalicyclic, the cylinder is stoppered and shaken five times.
The concentration of phosphorus in the extract samples are evaluated by comparison with the scale of standard extracts, prepared according to claim
In parallel spend control experience on the phosphorus content in the reagents through all stages of the analysis and impose on it the amendment.
3.3, 3.3.1−3.3.3. (Changed edition, Rev. N 1).
3.4. Processing of the results
3.4.1. Mass fraction of phosphorus in the sample () in percent is calculated by the formula
where is the mass of phosphorus found by comparison with the scale of standard extracts, µg;
— the weight of the portion,
For the results analysis be the arithmetic mean of two parallel definitions.
3.4.2. The difference between the larger and the smaller of the two results of parallel measurements with a confidence probability of 0.95 does not exceed the allowable absolute values of the differences of the two results of parallel measurements specified in the table.2.
Table 2
| Mass fraction of phosphorus, % |
The absolute allowable difference, % |
1·10 |
1·10 |
2·10 |
1,5·10 |
5·10 |
2·10 |
1·10 |
3·10 |
2·10 |
5·10 |
5·10 |
1·10 |
3.4.3. To verify the correctness of the analysis using the method of additives. Two parallel linkage according to claim 3 dissolved.3.1 ), calculated according to the formula
is the result of the analysis of the sample, %;
— the mass of phosphorus in the added volume of the working solution of phosphorus, µg), was not more than the upper limit of the interval defined by the mass fraction of phosphorus (see table.2) and at least tripled the value of the lower bound of this interval.
Analysis think is right with confidence probability of 0.95, if the result of analysis of batches with the addition of differs from
by no more than
where — the permissible discrepancy of the two results of parallel measurements of phosphorus in the sample with additive, %;
— the permissible discrepancy of the two results of parallel measurements of phosphorus in the same sample without additive, %.
4. A NEUTRON ACTIVATION METHOD FOR DETERMINATION OF PHOSPHORUS
The method is based on irradiation of the analysed samples and comparison of samples with neutron flux of 1.2·10on natural hair./(cm
·s) and then measure the activity of phosphorus-32 in the analyzed sample and the reference sample.
This method is applicable for determination of phosphorus in samples religiouznogo poly — and monocrystalline silicon samples doped with phosphorus.
(Changed edition, Rev. N 1).
4.1. Apparatus, materials and reagents
Nuclear reactor with a thermal neutron flux of 1−4,5·10on natural hair./ (cm
·s).
The radiometer of the type RFT-20046 with a plastic scintillator type or similar, providing a light indication.
Radiometer «TISS» or similar.
Analytical scale.
Analytical scale VLM-1G.
Box protective type 1B 11−1НЖ or similar.
Container lead transport stamps CL-7,0 with a wall thickness of 70 mm.
Container lead table brand CP1−10 with a wall thickness of 10 mm.
Personal protective equipment against radiation and contamination by radioactive substances, according to the basic sanitary rules OSP 72/80.
The aluminum canisters are made of aluminum brand 995-A.
Tile electric.
Lamp infrared type IP-1.
Phosphorus red OS.H. 9−3.
Aluminum foil stamps 995-A thickness of 0.05−0.1 mm.
The silicon semiconductor of the brand KP-1−6.
Exemplary standard beta emitters — thallium-204, or cobalt-60.
A substrate made of organic glass.
The filter is made of aluminium with a thickness of 0.22 g/cm.
Filter paper.
Volumetric flasks with a capacity of 50, 100 cm.
Measuring cylinders with a capacity of 10 and 25 cm.
Measuring cylinders made of organic glass with a capacity of 25, 50 cm.
Micropipette 0.1−0.5 and 1.0 cm.
Cups made of PTFE with a diameter of 20−22 (height 8−10 mm), and 35−50 mm (height 10−15 mm).
Pipettes made of organic glass.
Glasses chemical glass with a capacity of 50 and 100 cm.
Banks of PTFE at 250 and 500 cm.
The technical rectified ethyl alcohol GOST 18300−87.
Acetone according to GOST 2603−79.
Nitric acid according to GOST 11125−84.
Hydrofluoric acid according to GOST 10484−78.
Distilled water GOST 6709−72.
Carbon tetrachloride according to GOST 20288−74.
Potassium hydroxide GOST 9285−78.
Sodium hydroxide according to GOST 4328−77.
A standard solution of phosphorus with a concentration of 1·10g/cm
: a sample of phosphorus weighing 1·10
g were placed in a glass with a capacity of 50−100 cm
, add concentrated nitric acid and dissolved by heating. After complete dissolution of phosphorus and the solution was cooled to room temperature it is transferred into a measuring flask with a capacity of 100 cm
and adjusted with concentrated nitric acid to the mark. Then the solution was stirred.
The standard solutions of phosphorus to a concentration of 1·10g/cm
and 1·10
g/cm
is prepared in a similar manner, dissolving a portion of phosphorus with a mass of 1·10
and 1·10
g, respectively. Solutions used for validation Ana
Lisa.
(Changed edition, Rev. N 1).
4.2. Preparation for assay
4.2.1. Sample preparation silicon samples and comparison to irradiation
The canister for irradiation, quartz box and aluminum foil for packing the analyzed material was washed with acetone, then alcohol. The analyzed sample is weighed on an analytical balance (weight 1.5−3.0 g, sample thickness of 3−5 mm, diameter 15−20 mm) is placed in an aluminum package; the package label.
As a sample comparison, using a portion of the phosphorus 1−3·10g, which weighed on the scales VLM-1G and placed in a quartz box. Box wrapped in aluminum foil and labeled. The total mass of silicon in the pencil box should not exceed 20 g.
The canister is irradiated in a nuclear reactor neutron flux 1−4,5·10on natural hair./(cm
·C) for 1 h or 10 h depending on the expected concentration of phosphorus in the sample.
The irradiated silicon samples and samples comparison transportyou to the laboratory in a lead container CL-7,0.
(Changed edition, Rev. N 1).
4.2.2. Processing of silicon samples and comparison samples after irradiation
Pencil box with the irradiated samples and the comparison samples placed in a protective box. After 6 days, the samples recovered from aluminum packages, put each of them in a glass with a capacity of 50−100 cmand three times for 5 min. treated with carbon tetrachloride by boiling, adding after each 10−15 cm
of the reagent. Samples were then washed three times with hot acetone, alcohol, and transferred to a Cup made of PTFE. To the sample add 10−15 cm
of a freshly prepared mixture of hydrofluoric and nitric acids in the ratio 1:5 three times and each time for 20 s (without heating) is coated its surface, changing the mixture and washing the sample with distilled water after each etching. The ratio of solid and liquid phases should be between
to
.
After etching the sample is rinsed with alcohol, dried between sheets of filter paper, weighed on an analytical balance, placed in a bag made of plastic film, the package is marked and sent for measurement of activity.
4.3. Analysis
4.3.1. Measurement of activity
The correct operation of the radiometers RFT-20046 check according to the instructions.
Radiometer tested for stability using a source of beta-rays of thallium-204 or cobalt-60, measuring their activity. For this, a substrate with a source of beta radiation (cobalt-60) is placed in the third groove wall units (number of groove counts down from the detector) and measuring its activity twice, each time for 3−5 min.
After 6 days the backing of the analyzed sample is placed in the fourth groove wall units and measured activity of the sample, getting two of the measurements without filter and with filter two aluminum thickness of 0.22 g/cm, placing it in the third groove stack between the detector and analyzing the sample (the number of the groove counting down from the detector). The average of the two measurements with the filter (or no filter) should be at least 1000 imp. The total time to receive the results of all four measurements is 5−30 min. the measured activity of test sample is associated mainly with the decay of the radionuclide phosphorus-32 (half-life of 14.3 days). Such measurements are repeated 3−5 times with time interval 2−3 days. In the beginning before measuring activity of samples and at the end, after measuring the activity measured without filter background 3−5 times for 1 min by placing the substrate without the sample in the fourth groove shelves. The arithmetic mean of the results of measurements of the background (imp/min) is subtracted from the measurement results of the sample.
Immediately after measuring the activity of the sample (or before it) measured activity of the samples comparison. The comparison samples prepared from irradiated red phosphorus as follows: the linkage of phosphorus with a mass of 1·10g were placed in a glass with a capacity of 50−100 cm
, add concentrated nitric acid and dissolved by heating. After complete dissolution of phosphorus and the solution was cooled to room temperature, the solution was transferred to a volumetric flask with a capacity of 100 cm
and adjusted with concentrated acid to the mark; the solution was stirred. 0.5 cm
of this solution nakatyvaet three cups of PTFE with a diameter of 20−22 mm, which are pre-placed crushed silicon (the thickness of the silicon layer corresponds to the thickness of the analyzed sample), dried under a heat lamp for IP-1 and cover with plastic wrap. Activity comparison of samples measured in the same samples geometric conditions.
(Changed edition, Rev. N 1).
4.4. Processing of the results
4.4.1. Mass fraction of phosphorus (in) in the analyzed sample in percent is calculated by the formula
where and
— the mass of phosphorus in the reference sample, g;
— the mass of sample, g.
For the results analysis be the arithmetic mean of the two results of parallel measurements.
(Changed edition, Rev. N 1).
4.4.2. The difference between the larger and the smaller of the two results of parallel measurements with a confidence probability of 0.95 does not exceed the absolute value of permissible differences given in table.3.
Table 3
| Mass fraction of phosphorus, % | The absolute allowable difference, % |
1·10 |
1,0·10 |
1·10 |
2,0·10 |
2·10 |
3,0·10 |
4.4.3. Control of the correctness is carried out, using for this purpose the original formulas.
The original artificial mixtures prepared on the basis of high-purity silicon, crushed and powdered in an agate mortar to a powder, which is introduced phosphorus by the addition of the previously prepared standard solutions with the concentration of phosphorus 1·10, 1·10
* 1·10
* g/cm
. Powdered silica pre-check neutron-activation method on phosphorus content. Mass fraction of phosphorus in the powdered silicon should be not more than 2−5·10
%.
______________
* Corresponds to the original (repeat). — Note the manufacturer’s database.
A mixture of 1: to 10.0 g of powdered silicon is placed in an agate mortar, add 0.1 cmof a solution containing phosphorus (the phosphorus concentration of 1·10
g/cm
). Then under a layer of alcohol triturated with a mixture of 2.5−3.0 hours and the mixture is dried under an infrared lamp to constant weight.
Mass fraction of phosphorus in the mixture 1 is 1·10%.
A mixture of 2: to 10.0 g of powdered silicon add 0.1 cmof a solution containing phosphorus (the phosphorus concentration of 1·10
g/cm
), and then perform the procedures given in the preparation of compound 1.
Mass fraction of phosphorus in the mixture is 1·10%.
A mixture of 3: to 10.0 g of powdered silicon is added 0.01 cmof a solution containing phosphorus (the phosphorus concentration of 1·10
g/cm
), and then perform the procedures given in the preparation of compound 1.
Mass fraction of phosphorus in the mixture is 1·10%.
A mixture of 4: 10.0 g of powdered silicon is added to 0.02 cmof a solution containing phosphorus (the phosphorus concentration of 1·10
g/cm
), and then perform the procedures given in the preparation of compound 1.
Mass fraction of phosphorus in the mixture is 2·10%.
Of each prepared the initial synthetic mixture taken two hinges at the 2.0 g and analyzing according to claim
| A Mixture Of N 1 | 1·10 |
| A Mixture Of N 2 | 1·10 |
| A Mixture Of N 3 | 1·10 |
| A Mixture Of N 4 | 2·10 |
APP (mandatory). Single chamber autoclave With 3103
APP
Mandatory
1 — body of the autoclave; 2 — reaction vessel; 3 — a cover of the reaction vessel; 4 — housing cover of the autoclave; 5 — shut-off device; 6 — a tension nut
APP. (Added, Rev. N 1).
