ASTM D6401-99(2004)

Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials

SIGNIFICANCE AND USE
This test method is used to determine the proportion of the total soluble solids which are soluble non-tannins and the proportion which are tannins in a solution of tannin extract or in the water extract from raw or spent materials prepared for tannin analysis.
The specimens are aliquots from the analytical solutions prepared from tannin extracts or the water extract solutions prepared from raw or spent materials.
The soluble non-tannins are defined as the portion of the soluble solids which are not absorbed or bound by a prepared hide powder material.
The tannins are defined as the portion of the soluble solids which are absorbed or bound by a prepared hide powder material.
The results of this test method are dependent on a great many variables but particularly upon:  
5.5.1 The temperature conditions under which the solutions were prepared and stored and the temperature at which the current analysis is performed;
5.5.2 The uniformity and consistency of the Kaolin paste layer deposited onto the filter paper;
5.5.3 The rate of solution run-out from the pipette;
5.5.4 Conditions related to the properties of the hide powder used to react with the tannin content of the solution; etc. It is, therefore, essential that the method be followed exactly in order to obtain reproducible results both among specimens within a laboratory and for analyses between laboratories.
SCOPE
1.1 This test method is intended for use in determining the quantity of soluble non-tannins and tannin in solutions of tannin extracts, water extracts of vegetable tanning materials, or tanning liquors. The method is applicable to the analysis of liquid, solid, pasty, and powdered extracts and to extracts of raw or spent materials.
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
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 D6401-99 - Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials
• Effective Date: 01-Apr-2004
• Replaced By: ASTM D6401-99(2009) - Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials
• Effective Date: 01-Apr-2009
• Referred By: ASTM D4903-99(2020) - Standard Test Method for Total Solids and Water in Vegetable Tanning Material Extracts
• Effective Date: 01-Apr-2004
• Referred By: ASTM D6405-99(2020) - Standard Practice for Extraction of Tannins from Raw and Spent Materials
• Effective Date: 01-Apr-2004
• Referred By: ASTM D6408-99(2020) - Standard Test Method for Analysis of Tannery Liquors
• Effective Date: 01-Apr-2004
• Referred By: ASTM D4902-99(2020) - Standard Test Method for Evaporation and Drying of Analytical Solutions
• 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
• Referred By: ASTM D6406-99(2020) - Standard Test Method for Analysis of Sugar in Vegetable Tanning Materials
• 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:D6401–99(Reapproved2004)
Standard Test Method for
Determining Non-Tannins and Tannin in Extracts of
Vegetable Tanning Materials
This standard is issued under the fixed designation D 6401; 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 2.2 ALCA Method:
A22 Non-Tannins and Tannin
1.1 This test method is intended for use in determining the
quantity of soluble non-tannins and tannin in solutions of
3. Terminology
tannin extracts, water extracts of vegetable tanning materials,
3.1 Definitions:
or tanning liquors. The method is applicable to the analysis of
3.1.1 soluble non-tannins—non-volatilematerialspresentin
liquid, solid, pasty, and powdered extracts and to extracts of
tannin extracts and raw or spent materials that are dissolved or
raw or spent materials.
suspendedinwater,arepartofthesolublesolidsdeterminedby
1.2 The values stated in SI units are to be regarded as the
Test Method D 6402, and do not react with or bind to hide
standard. The inch-pound units given in parentheses are for
powder when mixed as in this test method.
information only.
3.1.2 tannins—non-volatile materials present in tannin ex-
1.3 This standard does not purport to address all of the
tracts and raw or spent materials that are dissolved or sus-
safety concerns, if any, associated with its use. It is the
pended in water, are part of the soluble solids determined by
responsibility of the user of this standard to establish appro-
Test Method D 6402, and do react with or bind to hide powder
priate safety and health practices and determine the applica-
when mixed as in this test method.
bility of regulatory limitations prior to use.
4. Summary of Test Method
2. Referenced Documents
2 4.1 An aliquot of the analytical solution prepared from
2.1 ASTM Standards:
tannin extracts (Practices D 4901 or D 4905) or of the water
D 2617 Test Method for Total Ash in Leather
extract from raw or spent materials (Practice D 6405) is dried
D 4901 Practice for Preparation of Solution of Liquid Veg-
overnight in a forced-air oven (Test Method D 4902) and the
etable Tannin Extracts
solid residue remaining is determined and defined as the total
D 4902 Test Method for Evaporation and Drying of Ana-
solids for that sample (Test Method D 4903). Another aliquot
lytical Solutions
of the same solution is passed through a specified filtering
D 4903 TestMethodforTotalSolidsandWaterinVegetable
procedure and the quantity of solid residue remaining in the
Tanning Material Extracts
filtrate is determined and defined as the soluble solids for that
D 4905 Practice for Preparation of Solution of Solid, Pasty,
sample; the calculated difference between the total solids and
and Powdered Vegetable Tannin Extracts
the soluble solids is defined as the insolubles for that sample
D 6402 Test Method for Determining Soluble Solids and
(Test Method D 6402).Another aliquot of the original analyti-
Insolubles in Extracts of Vegetable Tanning Materials
cal solution or water extract is mixed with a prepared hide
D 6405 Practice for Extraction of Tannins from Raw and
powder material with the resulting solution being passed
Spent Materials
through the same filtering procedure as for the soluble solids
analysis. The quantity of solid residue remaining in the filtrate
This test method is under the jurisdiction ofASTM Committee D31 on Leather
is determined and defined as the soluble non-tannins for that
and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
sample; the calculated difference between the total soluble
method has been adapted from and is a replacement for MethodA22 of the Official
solids and the soluble non-tannins is defined as the tannin
Methods of the American Leather Chemists Association.
content for that sample.
Current edition approved April 1, 2004. Published May 2004. Originally
approved in 1999. Last previous edition approved in 1999 as D 6401 – 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 Official Methods of the American Leather Chemists Association. Available
Standards volume information, refer to the standard’s Document Summary page on from the American Leather Chemists Association, University of Cincinnati, P.O.
the ASTM website. Box 210014, Cincinnati, OH 45221-0014.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6401–99 (2004)
5. Significance and Use 6.8 Shaking Machine,rotatingtype,equippedtohold0.95L
(32 oz) bottles for end-over-end agitation of hide powder and
5.1 This test method is used to determine the proportion of
analytical solution. The speed of rotation shall be 60 6 2 rpm,
the total soluble solids which are soluble non-tannins and the
and the machine shall be so constructed that the side of the
proportion which are tannins in a solution of tannin extract or
shake bottle adjacent to the rotating shaft shall be not less than
in the water extract from raw or spent materials prepared for
5.1 cm (2 in.) nor more than 7.6 cm (3 in.) from the center of
tannin analysis.
the shaft.
5.2 The specimens are aliquots from the analytical solutions
6.9 Cloth, The cloth shall be of cotton, with a nominal
prepared from tannin extracts or the water extract solutions
(unbleached) thread count of 48 by 48 and a weight of 1.65
prepared from raw or spent materials.
yards per 454 g (1 lb).When bleached, the thread count will be
5.3 The soluble non-tannins are defined as the portion of the
approximately 52 to 53 by 43 to 48.
soluble solids which are not absorbed or bound by a prepared
6.10 Kaolin , acid-washed kaolin clay which conforms to
hide powder material.
the following specifications:
5.4 The tannins are defined as the portion of the soluble
6.10.1 Suspend 1.0 g kaolin in 100 mL distilled water. The
solids which are absorbed or bound by a prepared hide powder
pH value should be between 4.5 and 6.0 after 5 min.
material.
6.10.2 Amixture of 2.0 g kaolin and 200 mLdistilled water
5.5 The results of this test method are dependent on a great
are shaken for 10 min and the mixture filtered through the
many variables but particularly upon:
standard filter paper (see 6.5). A 100 mL aliquot of the clear
5.5.1 The temperature conditions under which the solutions
filtrate should have less than 0.001 g of residue after evapora-
were prepared and stored and the temperature at which the
tion and oven-drying in a platinum dish.
current analysis is performed;
6.11 Chrome Alum Solution, a 3 % solution, prepared by
5.5.2 The uniformity and consistency of the Kaolin paste
dissolving CrK(SO ) 12 H O in distilled water at room
layer deposited onto the filter paper; 4 2 2
temperature (3 g per 100 mL of solution). The solution shall
5.5.3 The rate of solution run-out from the pipette;
not be more than 30 days old when used.
5.5.4 Conditionsrelatedtothepropertiesofthehidepowder
6.12 Hide Powder —The hide powder shall meet the fol-
used to react with the tannin content of the solution; etc. It is,
lowing specifications:
therefore, essential that the method be followed exactly in
6.12.1 The hide powder shall be finely ground and uniform
order to obtain reproducible results both among specimens
in texture with no lumps present.
within a laboratory and for analyses between laboratories.
6.12.2 The moisture content should be 12 to 15 % as
determined by Test Method D 4902.
6. Apparatus and Reagents
6.12.3 The ash content shall be less than 0.3 % as deter-
6.1 Tannin Dish, crystallizing dish, borosilicate glass, 50
mined by Test Method D 2617.
mm tall, 70 mm outside diameter. The bottom corner shall be
6.12.4 Amixturepreparedfrom7.0gofair-dryhidepowder
rounded to a radius of 6 mm, the bottom shall be flat and not
suspended in 100 mL of 0.1 N KCl and set aside for 24 h with
cupped in the center, and the top edge shall be rounded and
occasional shaking shall have a pH value not less than 5.0 nor
polished.
greater than 5.4.
6.2 Watch Glass, a suitable size (approximately 150 mm
6.12.5 Asample of the hide powder shall be carried through
diameter) to be used as a cover for the funnel and filter paper
the analytical procedure for the determination of non-tannins
and a suitable size (75 mm) to be used as a cover for the tannin
described below using distilled water in place of the analytical
dishes.
solution.Thewater-solublecontentoftheresultingfiltrateshall
6.3 Pipet, 100 mL capacity, preferably with a wide orifice
not exceed 0.004 g.
approximately 2.4 mm ( ⁄32 in.) diameter and 15-25 s delivery
6.12.6 Each new shipment of hide powder should be tested
time.
against the hide powder of the previous shipment using certain
6.4 Volumetric Flasks, graduated to deliver 200 mL boro-
standard extracts. The new hide powder shall give an average
silicate flask (Pyrex No. 5840 works well).
non-tannin percentage which differs by less than 6 0.2 from
6.5 Filter Paper , 21.5 cm diameter, pleated to contain 32
the comparable non-tannin percentage obtained with the hide
evenly divided creases.
powder from the previous shipment.
6.6 Funnel, 100 to 125 mm top diameter, 60° angle bowl,
6.12.7 Hide powder, prepared as described below, shall be
and 150 mm stem length.
used for the analysis of tanning materials on the same day that
6.7 Shake Bottles, 0.95 L(32 oz), with rubber stoppers. The
it is prepared.
bottles shall be approximately 21.6 cm (8.5 in.) overall height
6.13 Balance,analyticalbalancewhichwillweighupto100
and 8.9 cm (3.5 in.) diameter. One quart canning jars (Mason-
g with an accuracy of 6 0.1 mg (6 0.0001 g).
type) with plastic screw-on lids work well.
4 5
The sole source of supply of S&S No. 610 filter paper known to the committee The sole source of supply of Kaolin and hide powder known to the committee
at this time is Schleicher & Schuell, 10 OpticalAvenue, P.O. Box 2012, Keene, NH at this time is L. H. Lincoln & Son, Inc., 203 Cherry Street, Coudersport, PA16915.
03431. If you are aware of alternative suppliers, please provide this information to If you are aware of alternative suppliers, please provide this information to ASTM
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