ASTM D4794-94(2022)e1

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: D4794 − 94 (Reapproved 2022)
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 D4794; 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 (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Editorial update made to 1.3 and 9.1.8 in June 2022.
1. Scope 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
1.1 This test method is applicable to the determination of
the chromatograph used; or equivalent column and packing as
ethoxyl or hydroxyethoxyl substitution in cellulose ether prod-
appropriate.
ucts by a Zeisel gas chromatographic technique.
3.4 Syringe, 10 µL.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this 3.5 Reaction Vials, Caps, and Heating Block.
standard.
3.6 Syringe,100µL.
1.3 This standard does not purport to address all of the
3.7 Cover, stainless steel, fabricated to cover the heating
safety concerns, if any, associated with its use. It is the
block.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Reagents and Materials
mine the applicability of regulatory limitations prior to use.
4.1 Purity of Reagents—Reagent grade chemicals shall be
For specific hazard statements, see Section 5 and 9.1.8.1.
used in all tests. Unless otherwise indicated, it is intended that
1.4 This international standard was developed in accor-
all reagents shall conform to the specifications of the Commit-
dance with internationally recognized principles on standard-
tee onAnalytical Reagents of theAmerican Chemical Society,
ization established in the Decision on Principles for the
where such specifications are available. Other grades may be
Development of International Standards, Guides and Recom-
used, provided it is first ascertained that the reagent is of
mendations issued by the World Trade Organization Technical
sufficiently high purity to permit its use without lessening the
Barriers to Trade (TBT) Committee.
accuracy of the determination.
2. Summary of Test Method
4.2 Iodoethane, 99 % minimum.
2.1 When a cellulose ether containing ethyl or hydroxyethyl
4.3 O-xylene.
substitutes is allowed to react with hydriodic acid, one mole of
4.4 Toluene.
iodoethane is liberated for each mole of ethoxyl or hydroxy-
ethoxyl ether substituted on the cellulose chain. The iodoeth- 4.5 Hydriodic Acid, 57 % (sp gr 1.69 to 1.70).
ane is extracted in situ with o-xylene and quantitated by gas
4.6 Column Packing, 10 % methyl silicone stationary phase
chromatography using an internal standard technique. It is
USP code [G1] coated on inert diatomite solid support USP
recommended to run duplicate samples.
code [S1A], 100/120 mesh.
3. Apparatus
3.1 Gas Chromatograph with thermal conductivity detector
The sole source of supply of a heating block, Silli-Therm Heating Module,
and heated injection port.
Reacti-Block 21, Reacti-Vials, and Minnert valve tops, known to the committee at
this time is the Pierce Chemical Company P.O. Box 117, Rockford, IL61105–9976.
3.2 Electronic Integrator.
If you are aware of alternative suppliers, please provide this information to ASTM
International Headquarters. Your comments will receive careful consideration at a
meeting of the responsible technical committee, which you may attend.
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This test method is under the jurisdiction of ASTM Committee D01 on Paint ACS Reagent Chemicals, Specifications and Procedures for Reagents and
and Related Coatings, Materials, andApplications and is the direct responsibility of Standard-Grade Reference Materials, American Chemical Society, Washington,
Subcommittee D01.36 on Cellulose and Cellulose Derivatives. DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
in 1988. Last previous edition approved in 2017 as D4794 – 94 (2017). DOI: U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
10.1520/D4794-94R22E01. copeial Convention, Inc. (USPC), Rockville, MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4794 − 94 (2022)
5. Hazards 8.1.1 Calibrate the integrator according to the manufactur-
er’s instructions.
5.1 Safety precautions must be taken for handling of hydri-
odic acid. 8.2 If an integrator is not available peak areas and response
factors can be determined manually as follows:
5.2 During the reaction, the glass vials are under pressure.
Exercise precaution in handling the hot vials. A 3 w 3 P 3 F
RF 5 (1)
0.05 3 B 3 P
6. Apparatus Preparation and Conditioning
where:
6.1 Column (Note 1)—Columns are packed with reagent
RF = response factor,
under vacuum and mechanical vibration using silanized glass
A = peak height of internal standard (toluene),
wool to contain the packing. Install each in the gas chromato
...