ASTM D2976-71(2004)

Standard Test Method for pH of Peat Materials (Withdrawn 2013)

SIGNIFICANCE AND USE
pH measurements are made in water and in calcium chloride solution because the pH readings in water can be modified by salts, such as fertilizer material, whereas the observed pH in calcium chloride solution is virtually independent of the initial amount of salts present in the soil. pH values obtained in calcium chloride solution usually run about a 0.5 to 0.8 pH unit lower than measurements in water due to release of more hydrogen ions by cation exchange.
SCOPE
1.1 This test method covers the electrometric measurement of the pH of peat materials. It is a means of expressing the degree of acidity or alkalinity of peat material suspended in water and 0.01 M calcium chloride solution.
1.2 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.
WITHDRAWN RATIONALE
This test method covers the electrometric measurement of the pH of peat materials.
Formerly under the jurisdiction of Committee D18 on Soil and Rock, this test method was withdrawn in July 2013 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Historical
• Publication Date: 30-Jun-2004
• Withdrawal Date: 02-Jul-2013
• ICS: 65.080 - Fertilizers
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.22 - Media for Plant Growth

Relations

• Replaces: ASTM D2976-71(1998) - Standard Test Method for pH of Peat Materials
• Effective Date: 01-Jul-2004
• Referred By: ASTM F2396-11(2019) - Standard Guide for Construction of High Performance Sand-Based Rootzones for Athletic Fields
• Effective Date: 01-Jul-2004
• Referred By: ASTM D8198-18 - Standard Specification for Hydraulically Applied 100 % Wood Fiber Mulches
• Effective Date: 01-Jul-2004
• Referred By: ASTM D4427-23 - Standard Classification of Peat Samples by Laboratory Testing
• Effective Date: 01-Jul-2004
• Referred By: ASTM D8202-18 - Standard Specification for Hydraulically Applied 100% Wheat Straw Fiber Mulches
• Effective Date: 01-Jul-2004
• Referred By: ASTM F3339-20 - Standard Guide for Construction or Renovation of Native-soil Athletic Fields
• Effective Date: 01-Jul-2004
• Referred By: ASTM F2747-19 - Standard Guide for Construction of Sand-based Rootzones for Golf Putting Greens and Tees
• Effective Date: 01-Jul-2004

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: D2976 − 71 (Reapproved2004)
Standard Test Method for
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pH of Peat Materials
This standard is issued under the fixed designation D2976; 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 all reagents shall conform to the specifications of the Commit-
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tee on Analytical Reagents of the American Chemical Society,
1.1 This test method covers the electrometric measurement
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where such specifications are available. Other grades may be
of the pH of peat materials. It is a means of expressing the
used, provided it is first ascertained that the reagent is of
degree of acidity or alkalinity of peat material suspended in
sufficiently high purity to permit its use without lessening the
water and 0.01 M calcium chloride solution.
accuracy of the determination.
1.2 This standard does not purport to address all of the
5.2 Purity of Water—Water shall be carbon-dioxide-free
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- distilled water. Use water with a pH of not less than 6.5 nor
priate safety and health practices and determine the applica- more than 7.5, obtained by boiling distilled water for 15 min
bility of regulatory limitations prior to use. and cooling under carbon dioxide-free conditions.
5.3 Acid Potassium Phthalate Buffer Solution (0.05 M)—
2. Summary of Test Method
Dissolve 10.21 g (dried1hat 105°C) of potassium phthalate
2.1 The electrometric measurement of the pH of peat in
(NBS Standard Samples) in water and dilute to 1 L. Protect the
suspensions of water and calcium chloride solutions is made
solution against evaporation and contamination with molds.
with a potentiometer using a glass-calomel electrode system,
Replace the solution when mold is apparent. The effect of
calibrated with buffers of known pH.
temperature is as follows:
°C pH
3. Significance and Use
5to24 4.00
25 to 33 4.01
3.1 pH measurements are made in water and in calcium
34 to 37 4.02
chloride solution because the pH readings in water can be
modified by salts, such as fertilizer material, whereas the
5.4 Calcium Chloride, Stock Solution (1.0 M)—Dissolve
observed pH in calcium chloride solution is virtually indepen-
147 g of CaCl ·2H O in distilled water in a 1-L volumetric
2 2
dent of the initial amount of salts present in the soil. pH values
flask, cool, dilute to volume with distilled water, and mix.
obtained in calcium chloride solution usually run about a 0.5 to
Dilute 15 mL of this solution to 200 mL with distilled water in
0.8 pH unit lower than measurements in water due to release of
a volumetric flask, and standardize by titrating a 25-mLaliquot
more hydrogen ions by cation exchange.
of the diluted solution with standard 0.1 N silver nitrate
(AgNO ) solution using 1 mL of 5 % potassium chromate
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4. Apparatus
(K CrO ) solution as the indicator.
2 4
4.1 pH Meter—Potentiometer equipped with glass-calomel
5.5 Calcium Chloride Solution (0.01 M)—Dilute 20.0 mLof
electrode system. Follow the manufacturer’s instructions for
stock 1.0 M CaCl solution to 2 L with distilled water. The pH
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the pH meter used.
of this solution should be between 5 and 6.5.
5. Reagents
5.6 Phosphate Buffer Solution (0.025 M)—Dissolve 3.40 g
of KH PO and 3.55 g of Na HPO (NBS Standard Samples
5.1 Purity of Reagents—Reagent grade chemicals shall be
2 4 2 4
186-I and II) in water and dilute to 1 L. Dry salts2hat 130°C
used in all tests. Unless otherwise indicated, it is intended that
before use. Effect of temperature on pH is:
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This test method is under the jurisdiction ofASTM Committee D18 on Soil and
Rock and is the direct responsibility of Subcommittee D18.22 on Soil as a Medium
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for Plant Growth. Reagent Chemicals, American Chemical Society Specifications, American
Current edition approved July 1, 2004. Published July 2004. Originally approved Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
in 1971. Last previous edition approved in 1998 as D2976 - 71 (1998). DOI: listed by the American Chemical Society, see Annual Standards for Laboratory
10.1520/D2976-71R04. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
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This test method is currently undergoing an extensive review by ASTM and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Committee D18 and additional alternative methods will be proposed. MD.
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