ASTM D6407-99(2020)

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

SIGNIFICANCE AND USE
4.1 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 D4901, D6404, or D6405.  
4.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Nov-2020
• ICS: 59.140.10 - Processes and auxiliary materials
• Technical Committee: D31 - Leather
• Drafting Committee: D31.01 - Vegetable Leather

Relations

• Refers: ASTM D4901-99(2009) - Standard Practice for Preparation of Solution of Liquid Vegetable Tannin Extracts
• Effective Date: 01-Apr-2009
• Refers: ASTM D4902-99(2009) - Standard Test Method for Evaporation and Drying of Analytical Solutions
• Effective Date: 01-Apr-2009
• Refers: ASTM D6404-99(2009) - Standard Practice for Sampling Vegetable Materials Containing Tannin
• Effective Date: 01-Apr-2009
• Refers: ASTM D6405-99(2009) - Standard Practice for Extraction of Tannins from Raw and Spent Materials
• Effective Date: 01-Apr-2009
• Refers: ASTM D6405-99(2004) - Standard Practice for Extraction of Tannins from Raw and Spent Materials
• Effective Date: 01-Apr-2004
• Refers: ASTM D6404-99(2004) - Standard Practice for Sampling Vegetable Materials Containing Tannin
• Effective Date: 01-Apr-2004
• Refers: ASTM D4902-99(2004) - Standard Test Method for Evaporation and Drying of Analytical Solutions
• Effective Date: 01-Apr-2004
• Refers: ASTM D4901-99(2004) - Standard Practice for Preparation of Solution of Liquid Vegetable Tannin Extracts
• Effective Date: 01-Apr-2004
• Refers: ASTM D4902-99 - Standard Practice for Evaporation and Drying of Analytical Solutions
• Effective Date: 10-May-1999
• Refers: ASTM D6405-99 - Standard Practice for Extraction of Tannins from Raw and Spent Materials
• Effective Date: 10-May-1999
• Refers: ASTM D4901-99 - Standard Practice for Preparation of Solution of Liquid Vegetable Tannin Extracts
• Effective Date: 10-May-1999
• Refers: ASTM D6404-99 - Standard Practice for Sampling Vegetable Materials Containing Tannin
• Effective Date: 10-May-1999

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6407 − 99 (Reapproved 2020)
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 2.2 ALCA Methods:
A31 Method for Copper and Iron in Tanning Materials
1.1 This test method is intended for use in determining iron
and copper content in vegetable tanning materials. This test
3. Summary of Test Method
method is applicable to liquid, solid, pasty and powdered
3.1 A specified quantity of the tanning material is analyzed
extracts, to raw and spent materials, and to tannery liquors.
for iron and copper and content.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
4. Significance and Use
standard.
4.1 This test method is used to determine the quantity of
iron and copper present in vegetable tanning materials or
1.3 This standard does not purport to address all of the
vegetable tannin extracts prepared using Practices D4901,
safety concerns, if any, associated with its use. It is the
D6404,or D6405.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4.2 Because of the possibility of errors in this test method it
mine the applicability of regulatory limitations prior to use.
is essential that the method be followed exactly in order to
obtain reproducible results both among specimens within a
1.4 This international standard was developed in accor-
laboratory and for analyses between laboratories.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
5. Apparatus and Reagents
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5.1 Sulfuric Acid, concentrated (96 %).
Barriers to Trade (TBT) Committee.
5.2 Sulfuric Acid Solution, diluted 1:20 with distilled water.
5.3 Nitric Acid, fuming.
2. Referenced Documents
5.4 Hydrochloric Acid, concentrated (36 %).
2.1 ASTM Standards:
5.5 Hydrochloric Acid Solution, 0.1 N.
D4901 Practice for Preparation of Solution of Liquid Veg-
etable Tannin Extracts
5.6 Bromine Water, saturated solution.
D4902 Test Method for Evaporation and Drying of Analyti-
5.7 Ammonium Hydroxide Solution, concentrated diluted
cal Solutions
1:1 with distilled water.
D6404 Practice for Sampling Vegetable Materials Contain-
5.8 Potassium Permanganate Solution, 0.1 N.
ing Tannin
D6405 Practice for Extraction of Tannins from Raw and
5.9 Potassium (or Ammonium) Thiocyanate Solution, 10 g
Spent Materials
shall be dissolved in distilled water and diluted to 100 mLwith
distilled water.
5.10 Stock Iron Solution, This may be a purchased iron
This test method is under the jurisdiction ofASTM Committee D31 on Leather standard solution or may be prepared as follows:
and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
5.10.1 0.70 g of crystallized ferrous ammonium sulfate
test method has been adapted from and is a replacement for Method A31 of the
[FeSO ·(NH ) SO ·6H O] shall be dissolved in 50 mL of
4 4 2 4 2
Official Methods of the American Leather Chemists Association.
distilled water and 20 mL of dilute sulfuric acid (diluted 1:4).
Current edition approved Dec. 1, 2020. Published December 2020. Originally
approved in 1999. Last previous edition approved in 2014 as D6407 – 99 (2014).
DOI: 10.1520/D6407-99R20.
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
D6407 − 99 (2020)
5.10.2 This solution shall be titrated with 0.1 N potassium 7. General Instructions
permanganate solution until a faint pink persists for 1 minute
7.1 The distilled water shall be distilled from a glass,
and the iron is completely oxidized.
tin-lined,orblocktinstillandshallbestoredinglass,tin-lined,
5.10.3 Dilute this solution to 1 L with distilled water. 1 mL
or block tin containers.
of this solution is equivalent to 0.0001 g Fe.This solution shall
7.2 All apparatus used in this analysis shall be cleaned with
be stored in brown bottles and be protected from light.
hot hydrochloric acid solution (diluted 1 to 1) and rinsed with
5.10.4 Standard Iron Solution, 10 mL of the prepared stock
distilled water before use.
solution, or its equivalent of purchased iron standard solution,
shall be diluted to 100 mL with distilled water. 1 mL of this
7.3 Blank determinations shall be made to minimize errors
standard solution is equivalent to 0.00001 g Fe. The standard
due to iron or copper either present in the reagents used or
solution shall be freshly prepared for each analysis.
picked up during the analysis.
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
water, decant the supernatant through the same filter each time, and
6.1 The sample of material from which the test specimens
combinethefiltrates.Finallytransferthechartothefilterandwashseveral
are taken shall be
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