ASTM D1926-00(2019)
(Test Method)Standard Test Methods for Carboxyl Content of Cellulose
Standard Test Methods for Carboxyl Content of Cellulose
SIGNIFICANCE AND USE
3.1 These test methods measure the amount of carboxyl groups present in wood or cotton linter pulp. Carboxyl groups are indicative of the surface charge of the pulp which is a very important quantity for use in the papermaking industry.
SCOPE
1.1 These test methods cover the determination of the carboxyl content, or ion-exchange capacity, of cellulose from any source. Two test methods are described, the sodium chloride-sodium bicarbonate method (1)2 and the methylene blue method (2). The test methods must be used within their limitations, and it must be recognized that there is no way of determining the accuracy of any method for the determination of carboxyl. The precision of the sodium chloride-sodium bicarbonate method is low in the lower range of carboxyl values. The methylene blue method can be used over the whole range of carboxyl values; it is especially useful in the low range. It is not applicable to the determination of carboxyl in soluble carbohydrate material. Although these test methods may be used to determine the ion-exchange capacity of unbleached pulps, the residual lignin will cause an undetermined error, especially the sulfonic acid groups in unbleached sulfite pulps (3).
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 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.
General Information
Standards Content (Sample)
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.
Designation: D1926 − 00 (Reapproved 2019)
Standard Test Methods for
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Carboxyl Content of Cellulose
This standard is issued under the fixed designation D1926; 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.
1. Scope 2. Referenced Documents
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1.1 These test methods cover the determination of the 2.1 ASTM Standards:
carboxyl content, or ion-exchange capacity, of cellulose from D1193 Specification for Reagent Water
any source. Two test methods are described, the sodium
2 3. Significance and Use
chloride-sodium bicarbonate method (1) and the methylene
blue method (2). The test methods must be used within their
3.1 These test methods measure the amount of carboxyl
limitations, and it must be recognized that there is no way of groups present in wood or cotton linter pulp. Carboxyl groups
determining the accuracy of any method for the determination
are indicative of the surface charge of the pulp which is a very
of carboxyl. The precision of the sodium chloride-sodium important quantity for use in the papermaking industry.
bicarbonate method is low in the lower range of carboxyl
4. Purity of Reagents
values.Themethylenebluemethodcanbeusedoverthewhole
range of carboxyl values; it is especially useful in the low
4.1 Reagent-grade chemicals shall be used in all tests.
range. It is not applicable to the determination of carboxyl in
Unless otherwise indicated, it is intended that all reagents shall
soluble carbohydrate material. Although these test methods
conform to the specifications of the Committee on Analytical
may be used to determine the ion-exchange capacity of
Reagents of the American Chemical Society, where such
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unbleached pulps, the residual lignin will cause an undeter-
specifications are available. Other grades may be used, pro-
mined error, especially the sulfonic acid groups in unbleached
vided it is first ascertained that the reagent is of sufficiently
sulfite pulps (3).
high purity to permit its use without lessening the accuracy of
the determination.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
4.2 Unless otherwise indicated, references to water shall be
standard.
understood to mean reagent water conforming to Specification
D1193.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
SODIUM CHLORIDE-SODIUM BICARBONATE
responsibility of the user of this standard to establish appro-
METHOD
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
5. Summary of Test Method
1.4 This international standard was developed in accor-
5.1 In the sodium chloride-sodium bicarbonate method the
dance with internationally recognized principles on standard-
specimen is de-ashed with hydrochloric acid, washed, soaked
ization established in the Decision on Principles for the
in sodium chloride-sodium bicarbonate solution, filtered, and
Development of International Standards, Guides and Recom-
an aliquot of the filtrate titrated with 0.01 N hydrochloric acid
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
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These test methods are under the jurisdiction of ASTM Committee D01 on Standards volume information, refer to the standard’s Document Summary page on
Paint and Related Coatings, Materials, and Applications and are the direct the ASTM website.
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responsibility of Subcommittee D01.36 on Cellulose and Cellulose Derivatives. ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Current edition approved Dec. 1, 2019. Published December 2019. Originally Standard-Grade Reference Materials, American Chemical Society, Washington,
approved in 1961. Last previous edition approved in 2011 as D1926 – 00 (2011). DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
DOI: 10.1520/D1926-00R19. Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
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The boldface numbers in parentheses refer to the list of references at the end of U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
these test methods. copeial Convention, Inc. (USPC), Rockville, MD.
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