ASTM D6410-99(2004)

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 the 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-2004
• ICS: 59.140.10 - Processes and auxiliary materials
• Technical Committee: D31 - Leather
• Drafting Committee: D31.01 - Vegetable Leather

Relations

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

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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(Reapproved2004)
Standard Test Method for
Determining Acidity of Vegetable Tanning Liquors
This standard is issued under the fixed designation D 6410; 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 the vegetable tanning process and influence the astringency of
vegetable tanning liquors. The astringency of liquors is depen-
1.1 This test method covers determining the acidity of
dent upon the solids and tannin content and the acidity. This
tannery liquors made up from vegetable tanning materials.
test method provides a standard procedure for determining the
1.2 The values stated in SI units are to be regarded as the
total acidity for any sample of vegetable tanning liquor.
standard.
5.2 The specimens are aliquots from the analytical solution
1.3 This standard does not purport to address all of the
prepared from the sample of tannery liquor collected for this
safety concerns, if any, associated with its use. It is the
purpose.
responsibility of the user of this standard to establish appro-
5.3 The total acidity of the liquor sample is determined by
priate safety and health practices and determine the applica-
one of two titrametric procedures described in this test method.
bility of regulatory limitations prior to use.
6. Apparatus and Reagents
2. Referenced Documents
2 6.1 Analytical Solution:
2.1 ASTM Standards:
6.1.1 Flask,1Lvolumetric.ClassAflaskswithabulbinthe
D 6404 Practice for Sampling Vegetable Materials Contain-
neck (M.C.A. type) are especially suitable for this work.
ing Tannin
6.1.2 Hydrometer, preferably with a Barkometer scale (that
2.2 ALCA Methods:
is, a scale calibrated in °Bk).The three digits to the right of the
A25 Analysis of Tannery Liquors
decimal point on a standard specific gravity reading are equal
3. Terminology 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.
3.1 Definitions:
6.2 Acidity Determination—Method I:
3.1.1 tannery liquor—water solutions containing vegetable
6.2.1 Graduated Cylinder, glass-stoppered, graduated to
tannin that are made up and used in a vegetable tannery.
contain 250 mL.
4. Summary of Test Method
6.2.2 Gelatin Solution, 1 %, neutral to bromocresol purple.
The addition of 25 mL of 95 % ethyl alcohol per litre is
4.1 An analytical solution is prepared from the sample of
recommended to prevent frothing. The solution shall be ad-
tannery liquor (Practice D 6404). Specimen aliquots from this
justed to neutrality to bromocresol purple with 0.1 N acetic
analytical solution are then analyzed for total acidity by one of
acid or 0.1 N sodium hydroxide.
two titrametric methods.
6.2.3 Kaolin , acid-washed kaolin clay which conforms to
5. Significance and Use
the following specifications:
6.2.3.1 Suspend 1.0 g kaolin in 100 mL distilled water. The
5.1 This test method is used to determine one of the
pH value should be between 4.5 and 6.0 after 5 min.
chemical properties of tannery liquors which are relevant for
6.2.3.2 Amixture of 2.0 g kaolin and 200 mLdistilled water
are shaken for 10 min and the mixture filtered through the
This test method is under the jurisdiction ofASTM Committee D31 on Leather
standard filter paper (see 6.5). A 100 mL aliquot of the clear
and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
filtrate should have less than 0.001 g of residue after evapora-
test method has been adapted from and is a replacement for the acidity determina-
tion and oven-drying in a platinum dish.
tion portion of Method A25 of the Official Methods of the American Leather
Chemists Association.
6.2.4 Alkaline Titrant, 0.1 N sodium hydroxide solution.
Current edition approved April 1, 2004. Published May 2004. Originally
6.3 Acidity Determination—Method II:
approved in 1999. Last previous edition approved in 1999 as D 6410 – 99.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
...