ASTM D6407-99(2009)

Standard Test Method for Analysis of Iron and Copper in Vegetable Tanning Materials

SIGNIFICANCE AND USE
This test method is used to determine the quantity of iron and copper present in vegetable tanning materials or vegetable tannin extracts prepared using Practices D 4901, D 6404, or D 6405.
Because of the possibility of errors in this test method it is 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 iron and copper content in vegetable tanning materials. This test method is applicable to liquid, solid, pasty and powdered extracts, to raw and spent materials, and to tannery liquors.
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 D6407-99(2004) - Standard Test Method for Analysis of Iron and Copper in Vegetable Tanning Materials
• 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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D6407 − 99 (Reapproved2009)
Standard Test Method for
Analysis of Iron and Copper in Vegetable Tanning Materials
This standard is issued under the fixed designation D6407; 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 4. Significance and Use
1.1 This test method is intended for use in determining iron 4.1 This test method is used to determine the quantity of
and copper content in vegetable tanning materials. This test
iron and copper present in vegetable tanning materials or
method is applicable to liquid, solid, pasty and powdered
vegetable tannin extracts prepared using Practices D4901,
extracts, to raw and spent materials, and to tannery liquors.
D6404,or D6405.
1.2 The values stated in SI units are to be regarded as
4.2 Because of the possibility of errors in this test method it
standard. No other units of measurement are included in this
is essential that the method be followed exactly in order to
standard.
obtain reproducible results both among specimens within a
laboratory and for analyses between laboratories.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Apparatus and Reagents
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5.1 Sulfuric Acid, concentrated (96 %).
bility of regulatory limitations prior to use.
5.2 Sulfuric Acid Solution, diluted 1:20 with distilled water.
2. Referenced Documents
5.3 Nitric Acid, fuming.
2.1 ASTM Standards:
5.4 Hydrochloric Acid, concentrated (36 %).
D4901 Practice for Preparation of Solution of Liquid Veg-
5.5 Hydrochloric Acid Solution, 0.1 N.
etable Tannin Extracts
D4902 Test Method for Evaporation and Drying of Analyti-
5.6 Bromine Water, saturated solution.
cal Solutions
5.7 Ammonium Hydroxide Solution, concentrated diluted
D6404 Practice for Sampling Vegetable Materials Contain-
1:1 with distilled water.
ing Tannin
D6405 Practice for Extraction of Tannins from Raw and
5.8 Potassium Permanganate Solution, 0.1 N.
Spent Materials
5.9 Potassium (or Ammonium) Thiocyanate Solution, 10 g
2.2 ALCA Methods:
shall be dissolved in distilled water and diluted to 100 mLwith
A31 Method for Copper and Iron in Tanning Materials
distilled water.
3. Summary of Test Method 5.10 Stock Iron Solution, This may be a purchased iron
standard solution or may be prepared as follows:
3.1 A specified quantity of the tanning material is analyzed
5.10.1 0.70 g of crystallized ferrous ammonium sulfate
for iron and copper and content.
[FeSO •(NH ) SO •6H O] shall be dissolved in 50 mL of
4 4 2 4 2
distilled water and 20 mL of dilute sulfuric acid (diluted 1:4).
This test method is under the jurisdiction ofASTM Committee D31 on Leather
5.10.2 This solution shall be titrated with 0.1 N potassium
and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
permanganate solution until a faint pink persists for 1 minute
test method has been adapted from and is a replacement for Method A31 of the
and the iron is completely oxidized.
Official Methods of the American Leather Chemists Association.
Current edition approved April 1, 2009. Published July 2009. Originally 5.10.3 Dilute this solution to 1 L with distilled water. 1 mL
approved in 1999. Last previous edition approved in 2004 as D6407 – 99 (2004).
of this solution is equivalent to 0.0001 g Fe.This solution shall
DOI: 10.1520/D6407-99R09.
be stored in brown bottles and be protected from light.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.10.4 Standard Iron Solution, 10 mL of the prepared stock
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
solution, or its equivalent of purchased iron standard solution,
the ASTM website.
shall be diluted to 100 mL with distilled water. 1 mL of this
Official Methods of the American Leather Chemists Association. Available
standard solution is equivalent to 0.00001 g Fe. The standard
from the American Leather Chemists Association, University of Cincinnati, P.O.
Box 210014, Cincinnati, OH 45221-0014. solution shall be freshly prepared for each analysis.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6407 − 99 (2009)
5.11 Stock Copper Solution, 3.9283 g of copper sulfate 7.4 Duplicate determinations are recommended whenever
crystals (CuSO •5H O) shall be dissolved in distilled water possible.
4 2
and diluted to 1 L with distilled water. 1 mL of this solution is
7.5 In the actual colorimetric determinations described
equivalent to 0.001 g Cu.
below, the indicated volumes of reagents, and of the prepared
5.11.1 StandardCopperSolution,10mLofthestockcopper
solutions of the specimens and of standards, are based on the
solution shall be diluted to 1 L with distilled water and the pH
use 50 mL tall-form Nessler tubes. Other tube volumes and
adjusted to between 5.5 and 6.0. 1 mLof this standard solution
forms may be used, provided: they be used in matched sets and
is equivalent to 0.00001 g Cu. The standard solution shall be
the volumes of reagents, specimen and standard solutions be
freshly prepared for each analysis.
adjusted so that similar color intensities are produced. Such
5.12 Xanthate Solution, 1.0 g of potassium ethyl xanthate adjustments are automatic with, and familiar to, the experi-
shall be dissolved in distilled water and diluted to 1 L with
enced analyst and are not precluded by the method. If,
distilled water. The solution shall be freshly prepared for each however, the analyst is in doubt as to the proper adjustment to
analysis.
be made, it is recommended that 50 mLtall-form tubes be used
exactly as described.
5.13 Matched Nessler Tubes and Supporting Rack.
7.6 Comparison of the colors developed in the Nessler tubes
5.14 Balance,analyticalbalancewhichwillweighupto100
shall be made under a source of daylight from the north, the
g with an accuracy of 6 0.1 mg (6 0.0001 g).
tubes being held vertically two inches above an inclined sheet
5.15 Drying Oven, a forced-air convection oven (or
of white paper, and viewed downward through the full depth of
mechanical-convection draft oven) capable of maintaining a
liquid.
temperature of 100 6 2.0°C.
5.16 Thermometer, accurate to 6 0.2°C used to check and
8. Procedure
monitor the oven set point.
8.1 Transfer the specimen to a tared, glazed, porcelain dish
5.17 Dessicator, any convenient form or size, using any
or crucible of suitable size, taking care to avoid changes in
normal desiccant.
moisture content, and weigh to the nearest 0.1 mg (0.0001 g).
Where necessary, place the dish and specimen in the oven and
5.18 Glazed, Porcelain Dish or Crucible of Suitable Size.
evaporate to dryness (Test Method D4902).
5.19 Muffle Furnace, capable of maintaining a temperature
8.2 Ignite the dish containing the dried residue gently over
of 600° 6 25°C.
a low flame, at as low a temperature as possible, until the
5.20 Hotplate, ordinary lab grade.
residue is thoroughly charred and all smoke driven off. Then
5.21 Steam Bath, ordinary lab grade.
place the dish and charred residue in a muffle furnace and ash,
atatemperaturenotexceeding600°C,untilallcarbonhasbeen
5.22 Volumetric Flasks, 200 and 250 mL capacity.
removed.
5.23 Beakers, 250 mL.
NOTE1—Occasionally,thespecimenwillbeofsuchanaturethatallthe
5.24 Filter Paper, quantitative, Whatman grade 40 or 52 or
carbon cannot be removed as described above. In such a case, saturate the
similar.
charred mass with hot distilled water and break it up as completely as
possible with a glass rod. Then add more of the hot distilled water and
5.25 Buret, 10 mL capacity is sufficient.
digest the whole on the steam bath for a few minutes. Decant the
supernatant through a quantitative filter paper, collect the filtrate in a
6. Test Specimen
suitable receiver. Digest the charred residue twice more with hot distilled
6.1 The sample of material from which the test specimens water, decant the supernatant through the same filter each time, and
combinethefiltrates.Finallytransferthechartothefilterandwashseveral
are taken shall be prepared as described in Practice D6404 for
times with hot distilled water, the washings being combined with the
extracts and tannery liquor and as in the Preparation of Sample
filtrates. Then replace the filter and residue in the original dish, dry, and
section of Practice D6405 for raw and spent materials.
ash the whole, as before, until all the carbon has been removed. Cool the
dish, quantitatively transfer the combined filtrates and washings thereto
6.2 The specimen shall consist of5gof solid extract or its
and evaporate and dry. Then place the dish and contents in a cold muffle
equivalent (that is 10 g of liquid extract; 25 to 50 g of tannery
furnace,raisethetemperature,slowlya
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