ASTM D1106-21

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: D1106 − 21
Standard Test Method for
1,2
Acid-Insoluble Lignin in Wood
This standard is issued under the fixed designation D1106; 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 would remain insoluble with the lignin, these are first removed
3
by extraction with suitable solvents. The 72 % sulfuric acid
1.1 This test method covers the determination of the
method for lignin contains two and sometimes three prelimi-
acid-insoluble lignin content of wood.
nary extractive treatments of the wood, namely: (1) with
1.2 This standard does not purport to address all of the
ethanol, to remove the catechol tannins; (2) with ethanol-
safety concerns, if any, associated with its use. It is the
toluene solution, to remove the resins, oils, fats and waxes; and
responsibility of the user of this standard to establish appro-
(3) with hot water, to remove the remaining water-soluble
priate safety, health, and environmental practices and deter-
materials.
mine the applicability of regulatory limitations prior to use.
3.2 The ethanol extraction is necessary in analysis of woods
Specific precautionary statements are given in 6.1.
high in tannin; that is, oak, chestnut, redwood, etc. It has not
1.3 This international standard was developed in accor-
been shown necessary in the more common pulpwoods, such
dance with internationally recognized principles on standard-
as the various species of spruce, pine, fir, hemlock, poplar,
ization established in the Decision on Principles for the
birch, beech, and maple. It is recommended that for these
Development of International Standards, Guides and Recom-
woods the alcohol extraction be omitted unless it is desirable
mendations issued by the World Trade Organization Technical
for a special purpose. In analysis of woods not listed, the
Barriers to Trade (TBT) Committee.
desirability of the alcohol extraction depends upon the purpose
2. Referenced Documents of the analysis and the report should state whether or not
4 ethanol extraction was used.
2.1 ASTM Standards:
D1107 Test Method for Ethanol-Toluene Solubility of Wood
4. Significance and Use
3. Principle of Method
4.1 Wood contains approximately 20 to 30 % lignin. Re-
3.1 When wood is treated with strong acids the carbohy- moval of the lignin is the primary objective of pulping and
drates are hydrolyzed, leaving an insoluble residue which is bleaching procedures. Determination of the lignin content
determined as acid-insoluble lignin. Since some of the wood provides information for the evaluation and application of
extractives (oils, resins, fats, waxes, tannins, gums, and starch) these processes.
5. Apparatus
1
This test method is under the jurisdiction of ASTM Committee D07 on Wood
5.1 Extraction Apparatus—A compact form of Soxhlet ex-
and is the direct responsibility of Subcommittee D07.01 on Fundamental Test
Methods and Properties.
traction apparatus, with ground-glass joints, is preferable. The
Current edition approved Feb. 1, 2021. Published March 2021. Originally
apparatus shall consist of the following items:
approved in 1950. Last previous edition approved in 2013 as D1106 – 96 (2013).
DOI: 10.1520/D1106-21. 5.1.1 Soxhlet Extraction Flask, having a capacity of 250
2
This standard was originally based upon TAPPI standard Method T222-om-83,
mL.
which has been replaced by T 222 om-15.
5.1.2 Soxhlet Extraction Tube, 45 to 50 mm in inside
3
For further information on this test method the following references may be
consulted: diameter, having a capacity to the top of the siphon of
Bray, M. W., “Methods Used at the Forest Products Laboratory for the Chemical
approximately 100 mL and a siphon tube approximately 55
Analysis of Pulps and Pulpwoods,”PaperTradeJournal,Vol 87, No. 25, December
mm in height. Extraction tubes of these dimensions siphon
20, 1928, p. 29.
more rapidly than extractors with higher siphon tubes.
Ritter, G. J., Seborg, R. M., Mitchell, R. L., Industrial and Engineering
Chemistry, Analytical Edition, Vol 4, 1932, p. 202.
5.1.3 Condenser, of the Hopkins inner-cooled type.
Ritter, G. J., and Barbour, J. H., Industrial and Engineering Chemistry,
5.1.4 Extraction Crucibles, of Alundum or fritted glass and
Analytical Edition, Vol 7, 1935, p. 238.
4
of medium or fine porosity.
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
5.2 Filtering Crucible
...