ASTM D4794-94(2003)
(Test Method)Standard Test Method for Determination of Ethoxyl or Hydroxyethoxyl Substitution in Cellulose Ether Products by Gas Chromatography
Standard Test Method for Determination of Ethoxyl or Hydroxyethoxyl Substitution in Cellulose Ether Products by Gas Chromatography
ABSTRACT
This test method is applicable to the determination of ethoxyl or hydroxyethoxyl substitution in cellulose ether products by a Zeisel gas chromatographic technique. The equipment and materials to be used shall include reagents, gas chromatograph, electronic integrator, column, syringe, reaction vials, caps, heating block, and a cover. The following reagents are as follows: iodoethane, O-xylene, toluene, hydrochloric acid, and colume packing. When a cellulose ether containing ethyl or hydroxyethyl substitutes is allowed to react with hydriodic acid, one mole of iodoethane is liberated for each mole of ethoxyl or hydroxyethoxyl ether substituted on the cellulose chain. The iodoethane is extracted in-situ with o-xylene and quantitated by gas chromatography using an internal standard technique. It is recommended to run duplicate samples.
SCOPE
1.1 This test method is applicable to the determination of ethoxyl or hydroxyethoxyl substitution in cellulose ether products by a Zeisel gas chromatographic technique.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 5 and Note 3.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4794–94(Reapproved2003)
Standard Test Method for
Determination of Ethoxyl or Hydroxyethoxyl Substitution in
Cellulose Ether Products by Gas Chromatography
This standard is issued under the fixed designation D 4794; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.5 Reaction Vials, Caps, and Heating Block.
3.6 Syringe, 100 µL.
1.1 This test method is applicable to the determination of
3.7 Cover, stainless steel, fabricated to cover the heating
ethoxyl or hydroxyethoxyl substitution in cellulose ether prod-
block.
ucts by a Zeisel gas chromatographic technique.
1.2 The values stated in SI units are to be regarded as the
4. Reagents and Materials
standard. The values given in parentheses are for information
4.1 Purity of Reagents—Reagent grade chemicals shall be
only.
used in all tests. Unless otherwise indicated, it is intended that
1.3 This standard does not purport to address all of the
all reagents shall conform to the specifications of the Commit-
safety concerns, if any, associated with its use. It is the
tee onAnalytical Reagents of theAmerican Chemical Society,
responsibility of the user of this standard to establish appro-
where such specifications are available. Other grades may be
priate safety and health practices and determine the applica-
used, provided it is first ascertained that the reagent is of
bility of regulatory limitations prior to use. For specific hazard
sufficiently high purity to permit its use without lessening the
statements, see Section 5 and Note 3.
accuracy of the determination.
2. Summary of Test Method 4.2 Iodoethane, 99 % minimum.
4.3 O-xylene.
2.1 When a cellulose ether containing ethyl or hydroxyethyl
4.4 Toluene.
substitutes is allowed to react with hydriodic acid, one mole of
4.5 Hydriodic Acid, 57 % (sp gr 1.69 to 1.70).
iodoethane is liberated for each mole of ethoxyl or hydroxy-
4.6 Column Packing, 10 % methyl silicone stationary phase
ethoxyl ether substituted on the cellulose chain. The iodoet-
USP code [G1] coated on inert diatomite solid support USP
hane is extracted in-situ with o-xylene and quantitated by gas
code [S1A], 100/120 mesh.
chromatography using an internal standard technique. It is
recommended to run duplicate samples.
5. Hazards
3. Apparatus 5.1 Safety precautions must be taken for handling of hydri-
odic acid.
3.1 Gas Chromatograph withthermalconductivitydetector
5.2 During the reaction, the glass vials are under pressure.
and heated injection port.
Exercise precaution in handling the hot vials.
3.2 Electronic Integrator.
3.3 Column—stainless steel, 1829 mm in length, 3.2 mm in
outside diameter, packed with the reagent in 4.6, coiled to fit
The sole source of supply of a heating block, Silli-Therm Heating Module,
Reacti-Block 21, Reacti-Vials, and Minnert valve tops, known to the committee at
the chromatograph used; or equivalent column and packing as
this time is the Pierce Chemical Company P.O. Box 117, Rockford, IL61105–9976.
appropriate.
If you are aware of alternative suppliers, please provide this information to ASTM
3.4 Syringe,10µL.
International Headquarters. Your comments will receive careful consideration at a
meeting of the responsible technical committee, which you may attend.
Reagent Chemicals, American Chemical Society Specifications, American
This test method is under the jurisdiction of ASTM Committee D01 on Paint Chemical Society, Washington, DC. For suggestions on the testing of reagents not
and Related Coatings, Materials, andApplications and is the direct responsibility of listed by the American Chemical Society, see Analar Standards for Laboratory
Subcommittee D01.36 on Cellulose and Cellulose Derivatives. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Current edition approved Oct. 1, 2003. Published October 2003. Originally and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
approved in 1988. Last previous edition approved in 1994 as D 4794 – 94 (1998). MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4794–94 (2003)
6. Apparatus Preparation and Conditioning
A = peak height of internal standard (toluene),
w = weight of iodoethane, g,
6.1 Column (Note 1)—Columns are packed with reagent
P = purity of iodoethane,
under vacuum and mechanical vibration using silanized glass 1
F =
wool to contain the packing. Install each in the gas chromato-
factor of 0.289 for ethoxyl , 0.391 for
S D
graph to facilitate on column injection. Condition the column
hydroxyethoxyl,
at 200°C for 12 h, then allow it to come to equilibrium under
0.05 = weight of toluene, g,
the conditions described below:
B = peak height of iodoethane, and
Oven temperature, °C 130 isothermal
P = purity of toluene.
Injection port tempe
...
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