ASTM D6410-99(2009)

Standard Test Method for Determining Acidity of Vegetable Tanning Liquors

SIGNIFICANCE AND USE
This test method is used to determine one of the chemical properties of tannery liquors which are relevant for the vegetable tanning process and influence the astringency of vegetable tanning liquors. The astringency of liquors is dependent upon the solids and tannin content and the acidity. This test method provides a standard procedure for determining the total acidity for any sample of vegetable tanning liquor.
The specimens are aliquots from the analytical solution prepared from the sample of tannery liquor collected for this purpose.
The total acidity of the liquor sample is determined by one of two titrametric procedures described in this test method.
SCOPE
1.1 This test method covers determining the acidity of tannery liquors made up from vegetable tanning materials.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2009
• ICS: 59.140.10 - Processes and auxiliary materials
• Technical Committee: D31 - Leather
• Drafting Committee: D31.01 - Vegetable Leather

Relations

• Replaces: ASTM D6410-99(2004) - Standard Test Method for Determining Acidity of Vegetable Tanning Liquors
• Effective Date: 01-Apr-2009
• Referred By: ASTM D6408-99(2020) - Standard Test Method for Analysis of Tannery Liquors
• Effective Date: 01-Apr-2009
• Referred By: ASTM D4899-99(2020) - Standard Practice for Analysis of Vegetable Tanning Materials—General
• Effective Date: 01-Apr-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D6410 − 99 (Reapproved2009)
Standard Test Method for
Determining Acidity of Vegetable Tanning Liquors
This standard is issued under the fixed designation D6410; 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 analytical solution are then analyzed for total acidity by one of
two titrametric methods.
1.1 This test method covers determining the acidity of
tannery liquors made up from vegetable tanning materials.
5. Significance and Use
1.2 The values stated in SI units are to be regarded as
5.1 This test method is used to determine one of the
standard. No other units of measurement are included in this
chemical properties of tannery liquors which are relevant for
standard.
the vegetable tanning process and influence the astringency of
1.3 This standard does not purport to address all of the
vegetable tanning liquors. The astringency of liquors is depen-
safety concerns, if any, associated with its use. It is the
dent upon the solids and tannin content and the acidity. This
responsibility of the user of this standard to establish appro-
test method provides a standard procedure for determining the
priate safety and health practices and determine the applica-
total acidity for any sample of vegetable tanning liquor.
bility of regulatory limitations prior to use.
5.2 The specimens are aliquots from the analytical solution
prepared from the sample of tannery liquor collected for this
2. Referenced Documents
purpose.
2.1 ASTM Standards:
5.3 The total acidity of the liquor sample is determined by
D4904 Practice for Cooling of Analytical Solutions
one of two titrametric procedures described in this test method.
D6404 Practice for Sampling Vegetable Materials Contain-
ing Tannin
6. Apparatus and Reagents
2.2 ALCA Methods:
6.1 Analytical Solution:
A25 Analysis of Tannery Liquors
6.1.1 Flask,1Lvolumetric.ClassAflaskswithabulbinthe
neck (M.C.A. type) are especially suitable for this work.
3. Terminology
6.1.2 Hydrometer, preferably with a Barkometer scale (that
3.1 Definitions:
is, a scale calibrated in °Bk).The three digits to the right of the
3.1.1 tannery liquor—water solutions containing vegetable
decimal point on a standard specific gravity reading are equal
tannin that are made up and used in a vegetable tannery.
to the Barkometer scale reading. That is, a sp.gr. of 1.200
equals 200°Bk and a sp.gr. of 1.020 equals 20°Bk.
4. Summary of Test Method
6.2 Acidity Determination—Method I:
4.1 An analytical solution is prepared from the sample of
6.2.1 Graduated Cylinder, glass-stoppered, graduated to
tannery liquor (Practice D6404). Specimen aliquots from this
contain 250 mL.
6.2.2 Gelatin Solution, 1 %, neutral to bromocresol purple.
The addition of 25 mL of 95 % ethyl alcohol per litre is
This test method is under the jurisdiction ofASTM Committee D31 on Leather
recommended to prevent frothing. The solution shall be ad-
and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
justed to neutrality to bromocresol purple with 0.1 N acetic
test method has been adapted from and is a replacement for the acidity determina-
tion portion of Method A25 of the Official Methods of the American Leather
acid or 0.1 N sodium hydroxide.
Chemists Association. 4
6.2.3 Kaolin , acid-washed kaolin clay which conforms to
Current edition approved April 1, 2009. Published July 2009. Originally
the following specifications:
approved in 1999. Last previous edition approved in 2004 as D6410 – 99 (2004).
DOI: 10.1520/D6410-99R09.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The sole source of supply of Kaolin known to the committee at this time is L.
the ASTM website. H. Lincoln & Son, Inc., 203 Cherry Street, Coudersport, PA16915. If you are aware
Official Methods of the American Leather Chemists Association. Available of alternative suppliers, please provide this information to ASTM Headquarters.
from the American Leather Chemists Association, University of Cincinnati, P.O. Your comments will receive careful consideration at a meeting of the responsible
Box 210014, Cincinnati, OH 45221-0014. technical committee, which you may attend.
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D6410 − 99 (2009)
6.2.3.1 Suspend 1.0 g kaolin in 100 mL distilled water. The stopper cylinder, and shake vigorously.Then allow the mixture
pH value should be between 4.5 and 6.0 after 5 min. to settle for at least 15 min.
6.2.3.2 Amixture of 2.0 g kaolin and 200 mLdistilled water 8.2.1.2 Then withdraw a 30 mL aliquot of the supernatant
are shaken for 10 min and the mixture filtered through the solution from the cylinder, dilu
...