3.1.6. Polypropylene for containers and closures EUROPEAN PHARMACOPOEIA 7.0
01/2008:30106
corrected 7.0
3.1.6. POLYPROPYLENE FOR CONTAINERS AND CLOSURES FOR PARENTERAL PREPARATIONS AND OPHTHALMIC PREPARATIONS
DEFINITION
Polypropylene consists of the homopolymer of propylene or of
a copolymer of propylene with not more than 25 per cent of
ethylene or of a mixture (alloy) of polypropylene with not more
than 25 per cent of polyethylene. It may contain additives.
PRODUCTION
A certain number of additives are added to the polymer in order to optimise their chemical, physical and mechanical properties in order to adapt them for the intended use. All these additives are chosen from the appended list which specifies for each product the maximum allowable content.
They may contain at most 3 antioxidants, one or several
lubricants or antiblocking agents as well as titanium dioxide as
opacifying agent when the material must provide protection
from light.
— butylhydroxytoluene (plastic additive 07) : maximum
0.125 per cent ;
— pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-4-
hydroxyphenyl)propionate] (plastic additive 09) :
maximum 0.3 per cent ;
— 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,
6(1H,3H,5H)-trione (plastic additive 13) : maximum 0.3 per
cent ;
— octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,
(plastic additive 11) : maximum 0.3 per cent ;
— ethylene bis[3,3-bis[3-(1,1-dimethylethyl)-4-
hydroxyphenyl]butanoate] (plastic additive 08) : maximum 0.3 per cent ;
— dioctadecyl disulfide (plastic additive 15) : maximum 0.3 per
cent ;
— 2,2′,2″,6,6′,6″-hexa-tert-butyl-4,4′,4″-[(2,4,6-trimethyl-1,3,5-
benzenetriyl)trismethylene]triphenol (plastic additive 10) :
maximum 0.3 per cent ;
— 2,2′-bis(octadecyloxy)-5,5′-spirobi[1,3,2-dioxaphosphinane]
(plastic additive 14) : maximum 0.3 per cent ;
— didodecyl 3,3′-thiodipropionate (plastic additive 16) :
maximum 0.3 per cent ;
— dioctadecyl 3,3′-thiodipropionate (plastic additive 17) :
maximum 0.3 per cent ;
— tris(2,4-di-tert-butylphenyl) phosphite (plastic additive 12) :
maximum 0.3 per cent ;
The total of antioxidant additives listed above does not exceed 0.3 per cent.
— hydrotalcite : maximum 0.5 per cent ;
— alkanamides : maximum 0.5 per cent ;
— alkenamides : maximum 0.5 per cent ;
— sodium silico-aluminate : maximum 0.5 per cent ; — silica : maximum 0.5 per cent ;
— sodium benzoate : maximum 0.5 per cent ;
— fatty acid esters or salts : maximum 0.5 per cent ; — trisodium phosphate : maximum 0.5 per cent ; — liquid paraffin : maximum 0.5 per cent ;
— zinc oxide : maximum 0.5 per cent ;
— talc : maximum 0.5 per cent ;
— magnesium oxide : maximum 0.2 per cent ;
— calcium stearate or zinc stearate or a mixture of both :
maximum 0.5 per cent ;
— titanium dioxide, only for materials for containers for
ophthalmic use : maximum 4 per cent.
The supplier of the material must be able to demonstrate that the qualitative and quantitative composition of the type sample is satisfactory for each production batch.
CHARACTERS
Appearance : powder, beads, granules or, after transformation, translucent sheets of varying thicknesses or containers.
Solubility : practically insoluble in water, soluble in hot aromatic hydrocarbons, practically insoluble in anhydrous ethanol, in hexane and in methanol.
It softens at temperatures beginning at about 120 °C. IDENTIFICATION
If necessary, cut the material to be examined into pieces of maximum dimension on a side of not greater than 1 cm. A. Infrared absorption spectrophotometry (2.2.24).
Preparation : to 0.25 g add 10 mL of toluene R and boil under a reflux condenser for about 15 min. Place a few drops of the hot solution on a sodium chloride disc and evaporate the solvent in an oven at 80 °C.
Absorption maxima : at 1375 cm− 1, 1170 cm− 1, 995 cm− 1 and 970 cm− 1.
The spectrum obtained is identical to the spectrum obtained
with the material selected for the type sample. If the material
to be examined is in the form of sheets, the identification
may be performed directly on a cut piece of suitable size. B. It complies with the supplementary tests corresponding to
the additives present (see Tests).
C. In a platinum crucible, mix about 20 mg with 1 g of
potassium hydrogen sulfate R and heat until completely
melted. Allow to cool and add 20 mL of dilute sulfuric
acid R. Heat gently. Filter the resulting solution. To the
filtrate add 1 mL of phosphoric acid R and 1 mL of strong
hydrogen peroxide solution R. If the substance is opacified
with titanium dioxide, an orange-yellow colour develops.
TESTS
If necessary, cut the material to be examined into pieces of
maximum dimension on a side of not greater than 1 cm.
Solution S1. Use solution S1 within 4 h of preparation. Place
25 g in a borosilicate-glass flask with a ground-glass neck.
Add 500 mL of water for injections R and boil under a reflux
condenser for 5 h. Allow to cool and decant. Reserve a portion
of the solution for the test for appearance of solution and filter
the rest through a sintered-glass filter (16) (2.1.2).
Solution S2. Place 2.0 g in a conical borosilicate-glass flask
with a ground-glass neck. Add 80 mL of toluene R and boil
under a reflux condenser with constant stirring for 1 h 30 min.
Allow to cool to 60 °C and add with continued stirring 120 mL
of methanol R. Filter the solution through a sintered-glass
filter (16) (2.1.2). Rinse the flask and the filter with 25 mL of a
mixture of 40 mL of toluene R and 60 mL of methanol R, add
the rinsings to the filtrate and dilute to 250.0 mL with the same
mixture of solvents. Prepare a blank solution.
Solution S3. Place 100 g in a conical borosilicate-glass flask
with a ground-glass neck. Add 250 mL of 0.1 M hydrochloric
acid and boil under a reflux condenser with constant stirring
for 1 h. Allow to cool and decant the solution.
Appearance of solution. Solution S1 is not more opalescent
than reference suspension II (2.2.1) and is colourless (2.2.2,
Method II).
Acidity or alkalinity. To 100 mL of solution S1 add 0.15 mL of BRP indicator solution R. Not more than 1.5 mL of 0.01 M sodium hydroxide is required to change the colour of the
indicator to blue. To 100 mL of solution S1 add 0.2 mL of
342 See the information section on general monographs (cover pages)
EUROPEAN PHARMACOPOEIA 7.0 3.1.6. Polypropylene for containers and closures
methyl orange solution R. Not more than 1.0 mL of 0.01 M
hydrochloric acid is required to reach the beginning of the
colour change of the indicator from yellow to orange.
Absorbance (2.2.25) : maximum 0.2, determined between
wavelengths of 220 nm to 340 nm on solution S1.
Reducing substances. To 20 mL of solution S1 add 1 mL
of dilute sulfuric acid R and 20 mL of 0.002 M potassium
permanganate. Boil under a reflux condenser for 3 min and
cool immediately. Add 1 g of potassium iodide R and titrate
immediately with 0.01 M sodium thiosulfate, using 0.25 mL
of starch solution R as indicator. Carry out a blank titration.
The difference between the titration volumes is not more than
0.5 mL.
Substances soluble in hexane. Place 10 g in a 250 mL conical
borosilicate-glass flask with a ground-glass neck. Add 100 mL
of hexane R and boil under a reflux condenser for 4 h, stirring
constantly. Cool in iced water and filter rapidly through a
sintered-glass filter (16) (2.1.2) maintaining the solution at
0 °C (the filtration time must be less than 5 min ; if necessary
the filtration may be accelerated by applying pressure to the
solution). Evaporate 20 mL of the filtrate in a tared glass dish
on a water-bath. Dry the residue in an oven at 100-105 °C for
1 h. The mass of the residue obtained must be within 10 per
cent of the residue obtained with the type sample and does not
exceed 5 per cent.
Extractable aluminium : maximum 1 ppm.
Atomic emission spectrometry (2.2.57).
Test solution. Use solution S3.
Reference solutions. Prepare the reference solutions using aluminium standard solution (200 ppm Al) R, diluted with 0.1 M hydrochloric acid.
Wavelength : use the emission of aluminium at 396.15 nm, the spectral background being taken as 396.25 nm.
Verify the absence of aluminium in the hydrochloric acid used. Extractable chromium : maximum 0.05 ppm.
Atomic emission spectrometry (2.2.57).
Test solution. Use solution S3.
Reference solutions. Prepare the reference solutions using
chromium standard solution (100 ppm Cr) R, diluting with a
mixture of 2 volumes of hydrochloric acid R and 8 volumes
of water R.
Wavelength : use the emission of chromium at 205.55 nm, the spectral background being taken as 205.50 nm.
Verify the absence of chromium in the hydrochloric acid used. Extractable titanium : maximum 1 ppm.
Atomic emission spectrometry (2.2.57).
Test solution. Use solution S3.
Reference solutions. Prepare the reference solutions using titanium standard solution (100 ppm Ti) R, diluted with 0.1 M hydrochloric acid.
Wavelength : use the emission of titanium at 336.12 nm, the spectral background being taken as 336.16 nm.
Verify the absence of titanium in the hydrochloric acid used. Extractable vanadium : maximum 0.1 ppm.
Atomic emission spectrometry (2.2.57).
Test solution. Use solution S3.
Reference solutions. Prepare the reference solutions using vanadium standard solution (1 g/L V) R, diluted with a mixture of 2 volumes of hydrochloric acid R and 8 volumes of water R. Wavelength : use the emission of vanadium at 292.40 nm, the spectral background being taken as 292.35 nm.
Verify the absence of vanadium in the hydrochloric acid used. Extractable zinc : maximum 1 ppm.
Atomic absorption spectrometry (2.2.23, Method I). Test solution. Use solution S3.
Reference solutions. Prepare the reference solutions using
zinc standard solution (10 ppm Zn) R, diluted with 0.1 M hydrochloric acid.
Source : zinc hollow-cathode lamp.
Wavelength : 213.9 nm.
Atomisation device : air-acetylene flame.
Verify the absence of zinc in the hydrochloric acid used.
Extractable heavy metals (2.4.8) : maximum 2.5 ppm.
Concentrate 50 mL of solution S3 to about 5 mL on a water-bath and dilute to 20.0 mL with water R. 12 mL of the solution
complies with test A. Prepare the reference solution using
2.5 mL of lead standard solution (10 ppm Pb) R.
Sulfated ash (2.4.14) : maximum 1.0 per cent, determined
on 5.0 g. This limit does not apply to material that has been
opacified with titanium dioxide.
SUPPLEMENTARY TESTS
These tests are to be carried out, in whole or in part, only if required by the stated composition of the material.
Phenolic antioxidants. Liquid chromatography (2.2.29).
Solvent mixture : acetonitrile R, tetrahydrofuran R (50:50 V/V). Test solution S21. Evaporate 50 mL of solution S2 to dryness in vacuo at 45 °C. Dissolve the residue with 5.0 mL of the solvent mixture. Prepare a blank solution from the blank solution
corresponding to solution S2.
Test solution S22. Evaporate 50 mL of solution S2 to dryness in vacuo at 45 °C. Dissolve the residue with 5.0 mL of methylene chloride R. Prepare a blank solution from the blank solution corresponding to solution S2.
Of the following reference solutions, only prepare those that are necessary for the analysis of the phenolic antioxidants stated in the composition of the substance to be examined.
Reference solution (a). Dissolve 25.0 mg of butylhydroxy-
toluene CRS (plastic additive 07) and 60.0 mg of plastic
additive 08 CRS in 10.0 mL of the solvent mixture. Dilute
2.0 mL of this solution to 50.0 mL with the solvent mixture. Reference solution (b). Dissolve 60.0 mg of plastic
additive 09 CRS and 60.0 mg of plastic additive 10 CRS in 10.0 mL of the solvent mixture. Dilute 2.0 mL of this solution to 50.0 mL with the solvent mixture.
Reference solution (c). Dissolve 60.0 mg of plastic
additive 11 CRS and 60.0 mg of plastic additive 12 CRS in 10 mL of methylene chloride R. Dilute 2.0 mL of this solution to 50.0 mL with methylene chloride R.
Reference solution (d). Dissolve 25.0 mg of butylhydroxy-
toluene CRS (plastic additive 07) in 10.0 mL of the solvent
mixture. Dilute 2.0 mL of this solution to 50.0 mL with the
solvent mixture.
Reference solution (e). Dissolve 60.0 mg of plastic
additive 08 CRS in 10.0 mL of the solvent mixture. Dilute
2.0 mL of this solution to 50.0 mL with the solvent mixture.
Reference solution (f). Dissolve 60.0 mg of plastic
additive 13 CRS in 10.0 mL of the solvent mixture. Dilute
2.0 mL of this solution to 50.0 mL with the solvent mixture.
Reference solution (g). Dissolve 60.0 mg of plastic
additive 09 CRS in 10.0 mL of the solvent mixture. Dilute
2.0 mL of this solution to 50.0 mL with the solvent mixture.
Reference solution (h). Dissolve 60.0 mg of plastic
additive 10 CRS in 10.0 mL of the solvent mixture. Dilute
2.0 mL of this solution to 50.0 mL with the solvent mixture.
Reference solution (i). Dissolve 60.0 mg of plastic
additive 11 CRS in 10.0 mL of methylene chloride R. Dilute
2.0 mL of this solution to 50.0 mL with methylene chloride R.
Reference solution (j). Dissolve 60.0 mg of plastic
additive 12 CRS in 10.0 mL of methylene chloride R. Dilute
2.0 mL of this solution to 50.0 mL with methylene chloride R.
General Notices (1) apply to all monographs and other texts 343
3.1.6. Polypropylene for containers and closures EUROPEAN PHARMACOPOEIA 7.0
A. If the substance to be examined contains plastic additive 07
and/or plastic additive 08, carry out the test as follows. Column :
— size : l = 0.25 m, Ø = 4.6 mm ;
— stationary phase : octadecylsilyl silica gel for
chromatography R (5 μm).
Mobile phase : water R, acetonitrile R (30:70 V/V). Flow rate : 2 mL/min.
Detection : spectrophotometer at 280 nm.
Injection : 20 μL of test solution S21, corresponding blank solution and reference solution (a), and either reference solution (d) or (e), or reference solutions (d) and (e).
Run time : 30 min.
System suitability :
— resolution : minimum 8.0 between the peaks due to plastic
additive 07 and plastic additive 08 in the chromatogram
obtained with reference solution (a) ;
— the chromatogram corresponding to test solution S21
only show peaks due to antioxidants stated in the
composition and minor peaks that also appear in the
chromatogram corresponding to the blank solution. Limit : the areas of the peaks in the chromatogram obtained with test solution S21 are less than the areas of the
corresponding peaks in the chromatograms obtained with reference solutions (d) and/or (e).
B. If the substance to be examined contains one or more of the
following antioxidants :
— plastic additive 09 ;
— plastic additive 10 ;
— plastic additive 11 ;
— plastic additive 12 ;
— plastic additive 13 ;
carry out the test as described above with the following modifications.
Mobile phase : water R, tetrahydrofuran R, acetonitrile R (10:30:60 V/V/V).
Flow rate : 1.5 mL/min.
Injection : 20 μL of test solution S21, corresponding blank
solution, reference solution (b) and reference solutions of
the antioxidants on the list above that are stated in the
composition.
System suitability :
— resolution : minimum 2.0 between the peaks due to plastic additive 09 and plastic additive 10 in the chromatogram obtained with reference solution (b) ;
— the chromatogram corresponding to test solution S21 only show peaks due to antioxidants stated in the composition and minor peaks that also appear in the chromatogram
corresponding to the blank solution.
Limit : the areas of the peaks in the chromatogram obtained with test solution S21 are less than the areas of the
corresponding peaks in the chromatograms obtained with reference solutions of the antioxidants on the list above that are stated in the composition.
C. If the substance to be examined contains plastic additive 11
and/or plastic additive 12, carry out the test as described
for plastic additive 07 and/or plastic additive 08 with the
following modifications.
Mobile phase : water R, 2-propanol R, methanol R (5:45:50 V/V/V).
Flow rate : 1.5 mL/min.
Injection : 20 μL of test solution S22, corresponding blank solution, reference solution (c), and either reference solution (i) or (j), or reference solutions (i) and (j).
System suitability :
— resolution : minimum 2.0 between the peaks due to plastic
additive 11 and plastic additive 12 in the chromatogram
obtained with reference solution (c) ;
— the chromatogram corresponding to test solution S22
only show peaks due to antioxidants stated in the
composition and minor peaks that also appear in the
chromatogram corresponding to the blank solution. Limit : the areas of the peaks in the chromatogram obtained with test solution S22 are less than the areas of the
corresponding peaks in the chromatograms obtained with reference solutions (i) and/or (j).
Non-phenolic antioxidants. Thin-layer chromatography (2.2.27).
Test solution S23. Evaporate 100 mL of solution S2 to dryness in vacuo at 45 °C. Dissolve the residue with 2 mL of acidified methylene chloride R.
Reference solution (k). Dissolve 60 mg of plastic
additive 14 CRS in methylene chloride R and dilute to 10 mL with the same solvent. Dilute 2 mL of the solution to 10 mL with acidified methylene chloride R.
Reference solution (l). Dissolve 60 mg of plastic additive 15 CRS in methylene chloride R and dilute to 10 mL with the same solvent. Dilute 2 mL of the solution to 10 mL with acidified methylene chloride R.
Reference solution (m). Dissolve 60 mg of plastic
additive 16 CRS in methylene chloride R and dilute to 10 mL with the same solvent. Dilute 2 mL of the solution to 10 mL with acidified methylene chloride R.
Reference solution (n). Dissolve 60 mg of plastic
additive 17 CRS in methylene chloride R and dilute to 10 mL with the same solvent. Dilute 2 mL of the solution to 10 mL with acidified methylene chloride R.
Reference solution (o). Dissolve 60 mg of plastic
additive 16 CRS and 60 mg of plastic additive 17 CRS in methylene chloride R and dilute to 10 mL with the same solvent. Dilute 2 mL of the solution to 10 mL with acidified methylene chloride R.
Plate : TLC silica gel GF254 plate R.
Mobile phase A : hexane R.
Mobile phase B : methylene chloride R.
Application : 20 μL of test solution S23, reference solution (o) and reference solutions corresponding to all the phenolic and non-phenolic antioxidants mentioned in the type composition of the material to be examined.
Development A : over a path of 18 cm with mobile phase A. Drying A : in air.
Development B : over a path of 17 cm with mobile phase B. Drying B : in air.
Detection : examine in ultraviolet light at 254 nm ; spray with alcoholic iodine solution R and examine in ultraviolet light at 254 nm after 10-15 min.
System suitability : reference solution (o) :
— the chromatogram shows 2 clearly separated spots.
Limits : any spots in the chromatogram obtained with test
solution S23 are not more intense than the spots in the same
positions in the chromatograms obtained with the reference
solutions.
Amides and stearates. Thin-layer chromatography (2.2.27). Test solution. Use solution S23 described in the test for non-phenolic antioxidants.
Reference solution (p). Dissolve 20 mg of stearic acid CRS (plastic additive 19) in methylene chloride R and dilute to 10 mL with the same solvent.
Reference solution (q). Dissolve 40 mg of plastic
additive 20 CRS in methylene chloride R and dilute to 20 mL with the same solvent.
344 See the information section on general monographs (cover pages)
EUROPEAN PHARMACOPOEIA 7.0 3.1.7. Poly(ethylene-vinyl acetate) for containers and tubing
Reference solution (r). Dissolve 40 mg of plastic
additive 21 CRS in methylene chloride R and dilute to 20 mL with the same solvent.
Plate : TLC silica gel GF254 plate R (2 plates).
A. Mobile phase : anhydrous ethanol R, trimethylpentane R
(25:75 V/V).
Application : 10 μL of solution S23 and reference solution (p). Development : over a path of 10 cm.
Drying : in air.
Detection : spray with a 2 g/L solution of
dichlorophenolindophenol sodium salt R in anhydrous ethanol R and heat in an oven at 120 °C for a few minutes to intensify the spots.
Limit : any spot corresponding to plastic additive 19 in the
chromatogram obtained with test solution S23 is identical in
position (RF about 0.5) but not more intense than the spot
in the same position in the chromatogram obtained with reference solution (p).
B. Mobile phase A : hexane R.
Mobile phase B : methanol R, methylene chloride R (5:95 V/V).
Application : 10 μL of solution S23 and reference solutions (q) and (r).
Development A : over a path of 13 cm with mobile phase A. Drying A : in air.
Development B : over a path of 10 cm with mobile phase B. Drying B : in air.
Detection : spray with a 40 g/L solution of phosphomolybdic acid R in anhydrous ethanol R ; heat in an oven at 120 °C until spots appear.
Limit : any spots corresponding to plastic additive 20 or
plastic additive 21 in the chromatogram obtained with
test solution S23 are identical in position (RF about 0.2)
but not more intense than the corresponding spots in the
chromatograms obtained with reference solutions (q) and (r).
01/2008:30107
3.1.7. POLY(ETHYLENE - VINYL ACETATE) FOR CONTAINERS AND TUBING FOR TOTAL PARENTERAL NUTRITION PREPARATIONS
DEFINITION
Poly(ethylene - vinyl acetate), complying with the following requirements, is suitable for the manufacture of containers and tubing for total parenteral nutrition preparations. It is obtained by copolymerisation of mixtures of ethylene and vinyl acetate. Content of vinyl acetate :
— material used for containers : a defined quantity of not more
than 25 per cent ;
— material used for tubing : a defined quantity of not more
than 30 per cent.
PRODUCTION
A certain number of additives are added to the polymer in order to optimise their chemical, physical and mechanical properties in order to adapt them for the intended use. All these additives are chosen from the appended list which specifies for each product the maximum allowable content.
Poly(ethylene - vinyl acetate) may contain not more than 3 of
the following antioxidants :
— butylhydroxytoluene (plastic additive 07) : maximum
0.125 per cent ;
— pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-4-
hydroxyphenyl)propionate] (plastic additive 09) :
maximum 0.2 per cent ;
— octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate
(plastic additive 11) : maximum 0.2 per cent ;
— tris(2,4-di-tert-butylphenyl) phosphite (plastic additive 12) :
maximum 0.2 per cent ;
— 2,2′,2″,6,6′,6″-hexa-tert-butyl-4,4′,4″-[(2,4,6-trimethyl-1,3,5-
benzenetriyl)trismethylene]triphenol (plastic additive 10) :
maximum 0.2 per cent.
It may also contain :
— oleamide (plastic additive 20) : maximum 0.5 per cent ;
— erucamide (plastic additive 21) : maximum 0.5 per cent ;
— calcium stearate or zinc stearate or a mixture of both :
maximum 0.5 per cent ;
— calcium carbonate or potassium hydroxide : maximum 0.5 per
cent ;
— colloidal silica : maximum 0.2 per cent.
The supplier of the material must be able to demonstrate that the qualitative and quantitative composition of the type sample is satisfactory for each production batch.
CHARACTERS
Appearance : beads, granules or, after transformation,
translucent sheets or tubing of varying thickness or samples of finished objects.
Solubility : practically insoluble in water, soluble in hot aromatic hydrocarbons, practically insoluble in anhydrous ethanol,
in methanol and in hexane, which dissolves, however, low molecular mass polymers.
It burns with a blue flame.
The temperature at which the substance softens changes with the vinyl acetate content : from about 100 °C for contents of a few per cent to about 70 °C for contents of 30 per cent.
IDENTIFICATION
If necessary, cut the samples of material to be examined into
pieces of maximum dimension on a side of not greater than
1 cm.
Infrared absorption spectrophotometry (2.2.24).
Preparation : to 0.25 g add 10 mL of toluene R and boil under a reflux condenser for about 15 min. Place a few drops of the solution obtained on a disc of sodium chloride and evaporate the solvent in an oven at 80 °C.
Absorption maxima due to vinyl acetate : at 1740 cm− 1,
1375 cm− 1, 1240 cm− 1, 1020 cm− 1 and 610 cm− 1.
Absorption maxima due to ethylene : at 2920-2850 cm− 1,
1470 cm− 1, 1460 cm− 1, 1375 cm− 1, 730 cm− 1 and 720 cm− 1.
The spectrum obtained is identical to the spectrum obtained
with the type sample provided by the manufacturer. If the
material to be examined is in the form of sheets, the spectrum
may be determined directly on a cut piece of suitable size.
TESTS
If necessary, cut the samples of the material to be examined into pieces of maximum dimension on a side of not greater than 1 cm.
Solution S1. Place 2.0 g in a borosilicate-glass flask with a
ground-glass neck. Add 80 mL of toluene R and heat under a
reflux condenser with constant agitation for 90 min. Allow to
cool to 60 °C and add 120 mL of methanol R to the flask with
constant stirring. Filter the solution through a sintered-glass
filter (16) (2.1.2). Rinse the flask and the filter with 25 mL of a
General Notices (1) apply to all monographs and other texts 345
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