ASTM D4794-94(1998)
(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
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 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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact
ASTM International (www.astm.org) for the latest information.
Designation: D 4794 – 94 (Reapproved 1998)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
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 4. Reagents and Materials
1.1 This test method is applicable to the determination of 4.1 Purity of Reagents—Reagent grade chemicals shall be
ethoxyl or hydroxyethoxyl substitution in cellulose ether prod- used in all tests. Unless otherwise indicated, it is intended that
ucts by a Zeisel gas chromatographic technique. all reagents shall conform to the specifications of the Commit-
1.2 This standard does not purport to address all of the tee on Analytical Reagents of the American Chem-ical Society,
safety concerns, if any, associated with its use. It is the where such specifications are available. Other grades may be
responsibility of the user of this standard to establish appro- used, provided it is first ascertained that the reagent is of
priate safety and health practices and determine the applica- sufficiently high purity to permit its use without lessening the
bility of regulatory limitations prior to use. For specific hazard accuracy of the determination.
statements, see Section 5 and Note 3. 4.2 Iodoethane, 99 % minimum.
4.3 O-xylene.
2. Summary of Test Method
4.4 Toluene.
2.1 When a cellulose ether containing ethyl or hydroxyethyl
4.5 Hydriodic Acid, 57 % (sp gr 1.69 to 1.70).
substitutes is allowed to react with hydriodic acid, one mole of 4.6 Column Packing, 10 % methyl silicone stationary phase
iodoethane is liberated for each mole of ethoxyl or hydroxy-
USP code [G1] coated on inert diatomite solid support USP
ethoxyl ether substituted on the cellulose chain. The iodoet- code [S1A], 100/120 mesh.
hane is extracted in-situ with o-xylene and quantitated by gas
5. Hazards
chromatography using an internal standard technique. It is
recommended to run duplicate samples. 5.1 Safety precautions must be taken for handling of hydri-
odic acid.
3. Apparatus
5.2 During the reaction, the glass vials are under pressure.
3.1 Gas Chromatograph with thermal conductivity detector
Exercise precaution in handling the hot vials.
and heated injection port.
6. Apparatus Preparation and Conditioning
3.2 Electronic Integrator.
3.3 Column—stainless steel, 1829 mm in length, 3.2 mm in 6.1 Column (Note 1)—Columns are packed with reagent
outside diameter, packed with the reagent in 4.6, coiled to fit under vacuum and mechanical vibration using silanized glass
the chromatograph used; or equivalent column and packing as wool to contain the packing. Install each in the gas chromato-
appropriate. graph to facilitate on column injection. Condition the column
3.4 Syringe,10μL. at 200°C for 12 h, then allow it to come to equilibrium under
3.5 Reaction Vials, Caps, and Heating Block. the conditions described below:
3.6 Syringe, 100 μL.
Oven temperature, °C 130 isothermal
Injection port temperature, °C 200
3.7 Cover, stainless steel, fabricated to cover the heating
Detector temperature, °C 250
block.
Detector current, ma 175 ma
Attenuation 1
Polarity A
Carrier gas helium
Column A, mL/min 30
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
Column B, mL/min 30
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.36 on Cellulose and Cellulose Derivatives.
Current edition approved April 15, 1994. Published June 1994. Originally
published as D 4794 – 88. Last previous edition D 4794 – 88.
2 3
The sole source of supply of a heating block, Silli-Therm Heating Module, Reagent Chemicals, American Chemical Society Specifications, American
Reacti-Block 21, Reacti-Vials, and Minnert valve tops, known to the committee at Chemical Society, Washington, DC. For suggestions on the testing of reagents not
this time is the Pierce Chemical Company P.O. Box 117, Rockford, IL 61105–9976. listed by the American Chemical Society, see Analar Standards for Laboratory
If you are aware of alternative suppliers, please provide this information to ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Headquarters. Your comments will receive careful consideration at a meeting of the and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
responsible technical committee, which you may attend. MD.
NOTICE:¬This¬standard¬has¬either¬been¬superceded¬and¬replaced¬by¬a¬new¬version¬or¬discontinued.¬
Contact¬ASTM¬International¬(www.astm.org)¬for¬the¬latest¬information.¬
D 4794
N
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