ASTM D6401-99
(Test Method)Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials
Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials
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.
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Designation: D 6401 – 99
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 A22 Non-Tannins and Tannin
1.1 This test method is intended for use in determining the
3. Terminology
quantity of soluble non-tannins and tannin in solutions of
3.1 Definitions:
tannin extracts, water extracts of vegetable tanning materials,
3.1.1 soluble non-tannins—non-volatile materials present in
or tanning liquors. The method is applicable to the analysis of
tannin extracts and raw or spent materials that are dissolved or
liquid, solid, pasty, and powdered extracts and to extracts of
suspended in water, are part of the soluble solids determined by
raw or spent materials.
Test Method D 6402, and do not react with or bind to hide
1.2 The values stated in SI units are to be regarded as the
powder when mixed as in this test method.
standard. The inch-pound units given in parentheses are for
3.1.2 tannins—non-volatile materials present in tannin ex-
information only.
tracts and raw or spent materials that are dissolved or sus-
1.3 This standard does not purport to address all of the
pended in water, are part of the soluble solids determined by
safety concerns, if any, associated with its use. It is the
Test Method D 6402, and do react with or bind to hide powder
responsibility of the user of this standard to establish appro-
when mixed as in this test method.
priate safety and health practices and determine the applica-
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
tannin extracts (Practices D 4901 or D 4905) or of the water
2.1 ASTM Standards:
extract from raw or spent materials (Practice D 6405) is dried
D 2617 Test Method for Total Ash in Leather
overnight in a forced-air oven (Test Method D 4902) and the
D 4901 Practice for Preparation of Solution of Liquid Veg-
2 solid residue remaining is determined and defined as the total
etable Tannin Extracts
solids for that sample (Test Method D 4903). Another aliquot
D 4902 Test Method for Evaporation and Drying of Ana-
2 of the same solution is passed through a specified filtering
lytical Solutions
procedure and the quantity of solid residue remaining in the
D 4903 Test Method for Total Solids and Water in Vegetable
2 filtrate is determined and defined as the soluble solids for that
Tanning Material Extracts
sample; the calculated difference between the total solids and
D 4905 Practice for Preparation of Solution of Solid, Pasty,
2 the soluble solids is defined as the insolubles for that sample
and Powdered Vegetable Tannin Extracts
(Test Method D 6402). Another aliquot of the original analyti-
D 6402 Test Method for Determining Soluble Solids and
2 cal solution or water extract is mixed with a prepared hide
Insolubles in Extracts of Vegetable Tanning Materials
powder material with the resulting solution being passed
D 6405 Practice for Extraction of Tannins from Raw and
2 through the same filtering procedure as for the soluble solids
Spent Materials
analysis. The quantity of solid residue remaining in the filtrate
2.2 ALCA Method:
is determined and defined as the soluble non-tannins for that
sample; the calculated difference between the total soluble
solids and the soluble non-tannins is defined as the tannin
This test method is under the jurisdiction of ASTM Committee D-31 on Leather content for that sample.
and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
method has been adapted from and is a replacement for Method A22 of the Official
Methods of the American Leather Chemists Association. Official Methods of the American Leather Chemists Association. Available
Current edition approved May 10, 1999. Published August 1999. from the American Leather Chemists Association, University of Cincinnati, P.O.
Annual Book of ASTM Standards, Vol 15.04. Box 210014, Cincinnati, OH 45221-0014.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6401
5. Significance and Use 6.8 Shaking Machine, rotating type, equipped to hold 0.95 L
(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 A mixture of 2.0 g kaolin and 200 mL distilled 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 Conditions related to the properties of the hide powder
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 A mixture prepared from 7.0 g of air-dry hide powder
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 A sample 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. The water-soluble content of the resulting filtrate shall
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, analytical balance which will weigh up to 100
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 Optical Avenue, P.O. Box 2012, Keene, NH at this time is L. H. Lincoln & Son, Inc., 203 Cherry Street, Coudersport, PA 16915.
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
ASTM Headquarters. Your comments will receive careful consideration at a meeting Headquarters. Your comments will receive careful consideration at a meeting of the
of the responsible technical com
...
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