ASTM D6401-99(2009)

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:  
The temperature conditions under which the solutions were prepared and stored and the temperature at which the current analysis is performed;
The uniformity and consistency of the Kaolin paste layer deposited onto the filter paper;
The rate of solution run-out from the pipette;
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-2009
• ICS: 59.140.10 - Processes and auxiliary materials
• Technical Committee: D31 - Leather
• Drafting Committee: D31.01 - Vegetable Leather

Relations

• Replaces: ASTM D6401-99(2004) - Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials
• 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 D6405-99(2020) - Standard Practice for Extraction of Tannins from Raw and Spent Materials
• Effective Date: 01-Apr-2009
• Referred By: ASTM D4902-99(2020) - Standard Test Method for Evaporation and Drying of Analytical Solutions
• 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
• Referred By: ASTM D4903-99(2020) - Standard Test Method for Total Solids and Water in Vegetable Tanning Material Extracts
• Effective Date: 01-Apr-2009
• Referred By: ASTM D6406-99(2020) - Standard Test Method for Analysis of Sugar in Vegetable Tanning Materials
• 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: D6401 − 99 (Reapproved2009)
Standard Test Method for
Determining Non-Tannins and Tannin in Extracts of
Vegetable Tanning Materials
This standard is issued under the fixed designation D6401; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.2 ALCA Method:
A22Non-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,
or tanning liquors. The method is applicable to the analysis of 3.1 Definitions:
liquid, solid, pasty, and powdered extracts and to extracts of
3.1.1 soluble non-tannins—non-volatile materials present in
raw or spent materials. tannin extracts and raw or spent materials that are dissolved or
suspendedinwater,arepartofthesolublesolidsdeterminedby
1.2 The values stated in SI units are to be regarded as the
Test Method D6402, 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 D6402, 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
4.1 An aliquot of the analytical solution prepared from
2.1 ASTM Standards:
tannin extracts (Practices D4901 or D4905) or of the water
D2617Test Method for Total Ash in Leather
extract from raw or spent materials (Practice D6405) is dried
D4901Practice for Preparation of Solution of Liquid Veg-
overnight in a forced-air oven (Test Method D4902) and the
etable Tannin Extracts
solid residue remaining is determined and defined as the total
D4902Test Method for Evaporation and Drying ofAnalyti-
solidsforthatsample(TestMethodD4903).Anotheraliquotof
cal Solutions
the same solution is passed through a specified filtering
D4903Test Method for Total Solids and Water in Vegetable
procedure and the quantity of solid residue remaining in the
Tanning Material Extracts
filtrate is determined and defined as the soluble solids for that
D4905Practice 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
D6402Test Method for Determining Soluble Solids and
(Test Method D6402). Another aliquot of the original analyti-
Insolubles in Extracts of Vegetable Tanning Materials
cal solution or water extract is mixed with a prepared hide
D6405Practice 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
is determined and defined as the soluble non-tannins for that
ThistestmethodisunderthejurisdictionofASTMCommitteeD31onLeather
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, 2009. Published July 2009. Originally
approved in 1999. Last previous edition approved in 2004 as D6401–99(2004).
DOI: 10.1520/D6401-99R09.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 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 (2009)
5. Significance and Use and 8.9 cm (3.5 in.) diameter. One quart canning jars (Mason-
type) with plastic screw-on lids work well.
5.1 This test method is used to determine the proportion of
the total soluble solids which are soluble non-tannins and the
6.8 Shaking Machine,rotatingtype,equippedtohold0.95L
proportion which are tannins in a solution of tannin extract or
(32 oz) bottles for end-over-end agitation of hide powder and
in the water extract from raw or spent materials prepared for
analytical solution. The speed of rotation shall be 60 6 2 rpm,
tannin analysis.
and the machine shall be so constructed that the side of the
shake bottle adjacent to the rotating shaft shall be not less than
5.2 Thespecimensarealiquotsfromtheanalyticalsolutions
5.1 cm (2 in.) nor more than 7.6 cm (3 in.) from the center of
prepared from tannin extracts or the water extract solutions
the shaft.
prepared from raw or spent materials.
6.9 Cloth, The cloth shall be of cotton, with a nominal
5.3 Thesolublenon-tanninsaredefinedastheportionofthe
(unbleached) thread count of 48 by 48 and a weight of 1.65
soluble solids which are not absorbed or bound by a prepared
yardsper454g(1lb).Whenbleached,thethreadcountwillbe
hide powder material.
approximately 52 to 53 by 43 to 48.
5.4 The tannins are defined as the portion of the soluble
solids which are absorbed or bound by a prepared hide powder
6.10 Kaolin , acid-washed kaolin clay which conforms to
material. the following specifications:
6.10.1 Suspend 1.0 g kaolin in 100 mL distilled water. The
5.5 The results of this test method are dependent on a great
pH value should be between 4.5 and 6.0 after 5 min.
many variables but particularly upon:
6.10.2 Amixture of 2.0 g kaolin and 200 mLdistilled water
5.5.1 The temperature conditions under which the solutions
are shaken for 10 min and the mixture filtered through the
were prepared and stored and the temperature at which the
standard filter paper (see 6.5). A100 mL aliquot of the clear
current analysis is performed;
filtrate should have less than 0.001 g of residue after evapora-
5.5.2 The uniformity and consistency of the Kaolin paste
tion and oven-drying in a platinum dish.
layer deposited onto the filter paper;
5.5.3 The rate of solution run-out from the pipette;
6.11 Chrome Alum Solution, a 3% solution, prepared by
5.5.4 Conditionsrelatedtothepropertiesofthehidepowder
dissolving CrK(SO ) 12 H O in distilled water at room
4 2 2
used to react with the tannin content of the solution; etc. It is,
temperature (3 g per 100 mL of solution). The solution shall
therefore, essential that the method be followed exactly in
not be more than 30 days old when used.
order to obtain reproducible results both among specimens
6.12 Hide Powder —The hide powder shall meet the fol-
within a laboratory and for analyses between laboratories.
lowing specifications:
6. Apparatus and Reagents
6.12.1 The hide powder shall be finely ground and uniform
6.1 Tannin Dish, crystallizing dish, borosilicate glass, 50
in texture with no lumps present.
mm tall, 70 mm outside diameter. The bottom corner shall be
6.12.2 The moisture content should be 12 to 15% as
rounded to a radius of 6 mm, the bottom shall be flat and not
determined by Test Method D4902.
cupped in the center, and the top edge shall be rounded and
6.12.3 The ash content shall be less than 0.3% as deter-
polished.
mined by Test Method D2617.
6.2 Watch Glass, a suitable size (approximately 150 mm
6.12.4 Amixturepreparedfrom7.0gofair-dryhidepowder
diameter) to be used as a cover for the funnel and filter paper
suspended in 100 mLof 0.1 N KCl and set aside for 24 h with
andasuitablesize(75mm)tobeusedasacoverforthetannin
occasional shaking shall have a pH value not less than 5.0 nor
dishes.
greater than 5.4.
6.12.5 Asampleofthehidepowdershallbecarriedthrough
6.3 Pipet, 100 mL capacity, preferably with a wide orifice
the analytical procedure for the determination of non-tannins
approximately 2.4 mm ( ⁄32 in.) diameter and 15-25 s delivery
described below using distilled water in place of the analytical
time.
solution.Thewater-solublecontentoftheresultingfiltrateshall
6.4 Volumetric Flasks, graduated to deliver 200 mL boro-
not exceed 0.004 g.
silicate flask (Pyrex No. 5840 works well).
6.12.6 Each new shipment of hide powder should be tested
6.5 Filter Paper , 21.5 cm diameter, pleated to contain 32
against the hide powder of the previous shipment using certain
evenly divided creases.
standard extracts. The new hide powder shall give an average
non-tannin percentage which differs by less than 6 0.2 from
6.6 Funnel, 100 to 125 mm top diameter, 60° angle bowl,
and 150 mm stem length. the comparable non-tannin percentage obtained with the hide
powder from the previous shipment.
6.7 Shake Bottles, 0.95 L(32 oz), with rubber stoppers.The
bottles shall be approximately 21.6 cm (8.5 in.) overall height
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 atthistimeisL.H.Lincoln&Son,Inc.,203CherryStreet,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 toASTM
ASTMHeadquarters.Yourcommentswillreceivecarefulconsiderationatameeting Headquarters.Your comments will receive careful consideration at a meeting of the
of the responsible technical committee, which you may attend. responsible technical committee, which you may attend.
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