ASTM D2810-13
(Test Method)Standard Test Method for pH of Leather
Standard Test Method for pH of Leather
SIGNIFICANCE AND USE
4.1 This test method is designed to measure the pH of a distilled-water extract of leather. This is considered to be a measure of the acidity or alkalinity of the leather. Excessive acidity or alkalinity may have a deleterious effect on the aging characteristics of leather.
4.2 This test method is suitable for development, control, and service evaluation of leather.
SCOPE
1.1 This test method covers the determination of the pH of all types of leather. This method does not apply to wet blue.
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.
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Designation: D2810 − 13
Standard Test Method for
1
pH of Leather
This standard is issued under the fixed designation D2810; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 5. Interferences
5.1 If the leather contains an excessive amount of fats or
1.1 This test method covers the determination of the pH of
greases or has been treated with a material to obtain water
all types of leather. This method does not apply to wet blue.
repellency, the wettability and consequently the extractability
1.2 The values stated in SI units are to be regarded as
may be affected.
standard. No other units of measurement are included in this
5.2 If the specimen is difficult or impossible to wet, it may
standard.
be treated by any of the following procedures:
1.3 This standard does not purport to address all of the
5.2.1 A vacuum may be used to effect wetting.
safety concerns, if any, associated with its use. It is the
5.2.2 Mix with the required amount of water for 1 min in a
responsibility of the user of this standard to establish appro-
2
disintegrator.
priate safety and health practices and determine the applica-
5.2.3 Extract the weighed specimen with a fat solvent in a
bility of regulatory limitations prior to use.
Soxhlet apparatus for 5 h. Allow the specimen to air until all
solvent has evaporated; then proceed as outlined in Section 10.
2. Referenced Documents
6. Apparatus
2.1 ASTM Standards:
D2813 Practice for Sampling Leather for Physical and 6.1 pH Meter, either battery or line-operated with a suitable
Chemical Tests electrode. The meter shall have a resolution of 0.1/0.01 pH
unit, and shall have a relative accuracy of 60.1/0.01 pH unit.
3. Terminology
6.2 Analytical Balance, sensitive to 0.01 g.
3.1 Definitions of Terms Specific to This Standard:
7. Reagents
3.1.1 The pH of a solution has been defined as the negative
7.1 Purity of Reagents—Reagent grade chemicals shall be
logarithm of the hydrogen ion activity. A solution of pH 7 is
used in all tests. Unless otherwise indicated, it is intended that
neutral at 24°C. Lower numbers indicate increasing acidity;
all reagents shall conform to the specifications of the Commit-
higher numbers, increasing alkalinity.
tee onAnalytical Reagents of theAmerican Chemical Society,
3
where such specifications are available. Other grades may be
4. Significance and Use
used, provided it is first ascertained that the reagent is of
4.1 This test method is designed to measure the pH of a
sufficiently high purity to permit its use without lessening the
distilled-water extract of leather. This is considered to be a
accuracy of the determination.
measure of the acidity or alkalinity of the leather. Excessive
7.2 Purity of Water—Unless otherwise indicated, references
acidity or alkalinity may have a deleterious effect on the aging
to water shall be understood to mean distilled water or water of
characteristics of leather.
equal purity. Distilled water shall have a pH value of not less
4.2 This test method is suitable for development, control,
than 5.5 nor more than 7.0 and shall give a residue of not more
and service evaluation of leather.
than 0.5 mg, when 100 mL is evaporated and dried in a
platinum dish.
1 2
This test method is under the jurisdiction ofASTM Committee D31 on Leather A Waring Blender has been found satisfactory.
3
and is the direct responsibility of Subcommittee D31.06 on ChemicalAnalysis.This Reagent Chemicals, American Chemical Society Specifications , American
test method was developed in cooperation with the American Leather Chemists Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Assn. (Standard Method B20 – 1969). listed by the American Chemical Society, see Analar Standards for Laboratory
Current edition approved May 1, 2013. Published May 2013. Originally Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
approved in 1969. Last previous edition approved in 2007 as D2810 – 07. DOI: and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
10.1520/D2810-13. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D2810 − 13
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7.3 Standard pH Solutions: 10. Procedure
7.3.1 Alkaline Phosphate Buffer Solution (0.01 M trisodium
10.1 Weigh the specimen in duplicate to the nearest 0.1 g
phosphate, pH = 11.72 at 25°C)—Dissolve 1.42 g of anhy-
and transfer to 250-mL Erlenmeyer flasks. Add
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2810 − 07 D2810 − 13
Standard Test Method for
1
pH of Leather
This standard is issued under the fixed designation D2810; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers the determination of the pH of all types of leather. This method does not apply to wet blue.
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.
2. Referenced Documents
2.1 ASTM Standards:
D2813 Practice for Sampling Leather for Physical and Chemical Tests
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 The pH of a solution has been defined as the negative logarithm of the hydrogen ion activity. A solution of pH 7 is neutral
at 24°C. Lower numbers indicate increasing acidity; higher numbers, increasing alkalinity.
4. Significance and Use
4.1 This test method is designed to measure the pH of a distilled-water extract of leather. This is considered to be a measure
of the acidity or alkalinity of the leather. Excessive acidity or alkalinity may have a deleterious effect on the aging characteristics
of leather.
4.2 This test method is suitable for development, control, and service evaluation of leather.
5. Interferences
5.1 If the leather contains an excessive amount of fats or greases or has been treated with a material to obtain water repellency,
the wettability and consequently the extractability may be affected.
5.2 If the specimen is difficult or impossible to wet, it may be treated by any of the following procedures:
5.2.1 A vacuum may be used to effect wetting.
2
5.2.2 Mix with the required amount of water for 1 min in a disintegrator.
5.2.3 Extract the weighed specimen with a fat solvent in a Soxhlet apparatus for 5 h. Allow the specimen to air until all solvent
has evaporated; then proceed as outlined in Section 910.
6. Apparatus
6.1 pH Meter, either battery or line-operated,line-operated with a glass electrode and reference electrode or suitable
combination suitable electrode. The meter shall have a resolution of 0.1/0.01 pH unit, and shall have a relative accuracy of
60.1/0.01 pH unit.
6.2 Analytical Balance, sensitive to 0.01 g.
1
This test method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.06 on Chemical Analysis. This test
method was developed in cooperation with the American Leather Chemists Assn. (Standard Method B20 – 1969).
Current edition approved April 1, 2007May 1, 2013. Published May 20072013. Originally approved in 1969. Last previous edition approved in 20012007 as
D2810 – 01.D2810 – 07. DOI: 10.1520/D2810-07.10.1520/D2810-13.
2
A Waring Blender has been found satisfactory.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D2810 − 13
7. Reagents
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
3
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean distilled water or water of
equal purity. Distilled water shall have a pH value of not less than 5.5 nor more than 7.0 and shall give a residue of not more than
0.5 mg, when 100 mL is evaporated and dried in a platinum dish.
4
7.3 Standard pH Solutions:
7.3.1 Alkaline Phosphate Buffer Solution (0.01 M trisodium phosphate, pH = 11.72 at 25°C)—Dissolve 1.42 g of anhydrous
disodium hydrogen phosphate (Na HPO ) in 100 mL of a 0.1 N carbonate-free solution of
...
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