ASTM D4905-99(2009)

Standard Practice for Preparation of Solution of Solid, Pasty and Powdered Vegetable Tannin Extracts

SIGNIFICANCE AND USE
The concentration of tannins in solid, pasty, and powdered extracts needs to be reduced to analytical strength for tannin analyses.
4.2 Vegetable tannin extracts are heterogeneous mixtures of components with varying solubility.
4.3 The solubility of such extracts is influenced by temperature and concentration, which affect the degree of dispersion and size of the component particles.
4.4 Since extracts have greater solubility in hot water than cold, it is desirable to dissolve and disperse an extract in hot water and then let the solution cool slowly to standard room temperature.
It is often difficult to reduce samples of solid and particularly pasty extracts to specimen size and at the same time ensure representative sampling. Therefore, caution is advised in drawing conclusions on the precision and bias of the results obtained on such extracts; where difficulties in sample preparation are experienced, little confidence can be placed in the results.
SCOPE
1.1 This practice covers a standard procedure for use in preparing the analytical solution required for the analysis of solid, pasty, or powdered vegetable tannin extracts.
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
• Technical Committee: D31 - Leather
• Drafting Committee: D31.01 - Vegetable Leather

Relations

• Replaces: ASTM D4905-99(2004) - Standard Practice for Preparation of Solution of Solid, Pasty and Powdered Vegetable Tannin Extracts
• Effective Date: 01-Apr-2009
• Referred By: ASTM D4904-99(2020) - Standard Practice for Cooling of Analytical Solutions
• 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
• Referred By: ASTM D6409-99(2020) - Standard Practice for Color Tests with Sheepskin Skiver
• 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 D4900-99(2020) - Standard Test Method for Lignosulfonates (Sulfite Cellulose) in Tanning Extracts
• 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 D6401-99(2020) - Standard Test Method for Determining Non-Tannins and Tannin in Extracts of Vegetable Tanning Materials
• Effective Date: 01-Apr-2009
• Referred By: ASTM D6402-99(2020) - Standard Test Method for Determining Soluble Solids and Insolubles in Extracts of 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: D4905 − 99 (Reapproved2009)
Standard Practice for
Preparation of Solution of Solid, Pasty and Powdered
Vegetable Tannin Extracts
This standard is issued under the fixed designation D4905; 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 practice covers a standard procedure for use in 4.1 The concentration of tannins in solid, pasty, and pow-
preparing the analytical solution required for the analysis of dered extracts needs to be reduced to analytical strength for
solid, pasty, or powdered vegetable tannin extracts. tannin analyses.
1.2 The values stated in SI units are to be regarded as 4.2 Vegetable tannin extracts are heterogeneous mixtures of
standard. No other units of measurement are included in this components with varying solubility.
standard.
4.3 The solubility of such extracts is influenced by tempera-
1.3 This standard does not purport to address all of the
ture and concentration, which affect the degree of dispersion
safety concerns, if any, associated with its use. It is the
and size of the component particles.
responsibility of the user of this standard to establish appro-
4.4 Since extracts have greater solubility in hot water than
priate safety and health practices and determine the applica-
cold, it is desirable to dissolve and disperse an extract in hot
bility of regulatory limitations prior to use.
water and then let the solution cool slowly to standard room
temperature.
2. Referenced Documents
4.5 It is often difficult to reduce samples of solid and
2.1 ASTM Standards:
particularly pasty extracts to specimen size and at the same
D4903 Test Method for Total Solids and Water in Vegetable
time ensure representative sampling. Therefore, caution is
Tanning Material Extracts
advised in drawing conclusions on the precision and bias of the
D4904 Practice for Cooling of Analytical Solutions
results obtained on such extracts; where difficulties in sample
D6403 Test Method for Determining Moisture in Raw and
preparation are experienced, little confidence can be placed in
Spent Materials
the results.
D6404 Practice for Sampling Vegetable Materials Contain-
ing Tannin
5. Specimen
2.2 ALCA Method:
5.1 The specimen shall consist of a portion of the extract
A11 Preparation of Solution of Solid, Pasty, and Powdered
sample, prepared as described in Practice D6404 , sufficient to
Extracts
give a solution containing as nearly as possible 4 g of tannin
3. Summary of Practice
per L (not less than 3.75 g, nor more than 4.25 g, per L).
3.1 This practice describes a procedure to follow in the
6. Apparatus and Reagents
preparation of analytical strength solutions from samples of
solid, pasty, and powdered vegetable tannin extracts.
6.1 Formaldehyde—40 % solution.
6.2 Toluene—Assay ≥ 99.5 %.
This practice is under the jurisdiction ofASTM Committee D31 on Leather and
6.3 Small Mortar and Pestle.
is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
practice has been adapted from and is a replacement for MethodA11 of the Official
6.4 1-L Volumetric Flask, M.C.A. type, mixing bulb style.
Methods of the American Leather Chemists Association.
Current edition approved April 1, 2009. Published July 2009. Originally
7. Procedure
approved in 1989. Last previous edition approved in 2004 as D4905 – 99 (2004).
DOI: 10.1520/D4905-99R09.
7.1 Emptythesampleontoasheetofclean,glazedpaper(or
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
suitable clean, smooth foil material), roughly crush any large
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
lumps, and quickly mix and quarter the whole. From each
the ASTM website.
quarter, take a small representative portion, quickly crush,
Official Methods of the American Leather Chemists Association. Available
transfer to a small, glass stoppered weighing bottle, and take to
from the American Leather Chemists Association, University of Cincinnati, P.O.
Box 210014, Cincinnati, OH 45221–0014. the balance.
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