ASTM D4901-99(2020)

Standard Practice for Preparation of Solution of Liquid Vegetable Tannin Extracts

SIGNIFICANCE AND USE
4.1 The concentration of tannin in extracts must be reduced to analytical strength (4 g tannin per L) for analysis.  
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 While the solubility is better in hot water than in cold water, it is appropriate to dissolve and disperse an extract in hot water and then let the solution cool slowly to standard room temperature.
SCOPE
1.1 This practice covers the preparation of a solution of liquid extract that is to be used in the tannin analysis of that extract.  
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 D4904-99(2009) - Standard Practice for Preparation of Solution of Liquid Vegetable Tannin Extracts
• 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 D6404-99(2004) - Standard Practice for Sampling Vegetable Materials Containing Tannin
• Effective Date: 01-Apr-2004
• Refers: ASTM D4904-99(2004) - Standard Practice for Preparation of Solution of Liquid Vegetable Tannin Extracts
• Effective Date: 01-Apr-2004
• Refers: ASTM D6404-99 - Standard Practice for Sampling Vegetable Materials Containing Tannin
• Effective Date: 10-May-1999
• Refers: ASTM D4904-99 - Standard Practice for Cooling of Analytical Solutions
• 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: D4901 − 99 (Reapproved 2020)
Standard Practice for
Preparation of Solution of Liquid Vegetable Tannin Extracts
This standard is issued under the fixed designation D4901; 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 the preparation of a solution of 4.1 The concentration of tannin in extracts must be reduced
liquid extract that is to be used in the tannin analysis of that to analytical strength (4 g tannin per L) for analysis.
extract.
4.2 Vegetable tannin extracts are heterogeneous mixtures of
1.2 The values stated in SI units are to be regarded as components with varying solubility.
standard. No other units of measurement are included in this
4.3 The solubility of such extracts is influenced by tempera-
standard.
ture and concentration, which affect the degree of dispersion
1.3 This standard does not purport to address all of the
and size of the component particles.
safety concerns, if any, associated with its use. It is the
4.4 While the solubility is better in hot water than in cold
responsibility of the user of this standard to establish appro-
water,itisappropriatetodissolveanddisperseanextractinhot
priate safety, health, and environmental practices and deter-
water and then let the solution cool slowly to standard room
mine the applicability of regulatory limitations prior to use.
temperature.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5. Apparatus and Reagents
ization established in the Decision on Principles for the
5.1 Formaldehyde—40 % solution.
Development of International Standards, Guides and Recom-
5.2 Toluene—assay ≥ 99.5 %.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
5.3 Flask,1Lvolumetric.TheClassAtype,withupperbulb
in neck, is especially suitable for this work.
2. Referenced Documents
6. Test Specimen
2.1 ASTM Standards:
D4904 Practice for Cooling of Analytical Solutions
6.1 The specimen shall consist of an aliquot of the sample,
D6404 Practice for Sampling Vegetable Materials Contain-
prepared as described in Practice D6404, sufficient to give a
ing Tannin
solution containing as nearly as possible,4gof tannin per L
2.2 ALCA Methods:
(not less than 3.75 g, nor more than 4.25 g, per L).
A10 Preparation of Solution of Liquid Extracts
7. Procedure
3. Summary of Practice
7.1 Prepare samples of liquid extracts as described in
3.1 This practice describes a technique found useful in the
Practice D6404, and allow to come to room temperature.
preparation of analytical strength solutions from samples of
Thoroughly mix at room temperature and transfer specimen to
liquid vegetable tannin extracts.
a tared container and stoppered to prevent loss of moisture.
Return no material which has been removed from the sample
This practice is under the jurisdiction ofASTM Committee D31 on Leather and for any other purpose (for example, for determination of
is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This
specific gravity, etc.) to the sample. Care must be taken that
practicehasbeenadaptedfrom,andisareplacementfor,MethodA10oftheOfficial
dried material around the neck of the stopper of the sample
Me
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