ASTM D7637-10(2021)

Standard Test Method for Determination of Glycerin Assay by Titration (Sodium Meta Periodate)

SIGNIFICANCE AND USE
4.1 This test method is based on the cold oxidation of the glycerol by sodium metaperiodate in a strong acidic medium. Formaldehyde and formic acid are produced in this reaction and the latter is used to measure the glycerol content by titration with standard sodium hydroxide solution, to a pH 8.1 ± 0.1. The glycerol content is expressed as a percentage (m/m).
4.2 Interferences—The glycerin sample should be free of organic compounds with more than two hydroxyl groups on adjacent carbon atoms (for example, sugars, glycols). These types of compounds may produce formic acid which interferes with the determination of the glycerol content.
SCOPE
1.1 This test method provides the quantitative determination of glycerin by the titrimetric method. It is applicable to all glycerin or glycerin/water mixtures >75 %.  
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 may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult the established and appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautions are listed in Section 8.  
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: 31-Aug-2021
• ICS: 71.080.60 - Alcohols. Ethers
• Technical Committee: D15 - Engine Coolants and Related Fluids
• Drafting Committee: D15.04 - Chemical Properties

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: D7637 − 10 (Reapproved 2021)
Standard Test Method for
Determination of Glycerin Assay by Titration (Sodium Meta
1
Periodate)
This standard is issued under the fixed designation D7637; 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 Other Standards:
The United States Pharmacopoeia 31 Glycerin Monograph –
1.1 Thistestmethodprovidesthequantitativedetermination
3
Assay Method
of glycerin by the titrimetric method. It is applicable to all
AOCS Official Method EA6-94 (ReplacesAOCS EA6-51),
glycerin or glycerin/water mixtures >75 %. 4
Determination of Crude Glycerin, Titrimetric Method
BS 5711: Part 3, 1979 Sampling and Test for Glycerol -
1.2 The values stated in SI units are to be regarded as
5
Determination of Glycerol Content
standard. No other units of measurement are included in this
standard.
3. Terminology
1.3 This standard may involve hazardous materials,
3.1 Definitions:
operations, and equipment. This standard does not purport to
3.1.1 glycerin—propane-1,2,3-triol, C H (OH) (also
3 5 3
address all of the safety concerns associated with its use. It is
known as glycerine), 1,2,3-propanetriol, 1,2,3-
the responsibility of the user of this standard to consult the
trihydroxypropane, glyceritol, glycyl alcohol, glycerol. CAS
established and appropriate safety, health, and environmental
#56-81-5.
practices and determine the applicability of regulatory limita-
3.1.2 SMP—Sodium Meta Periodate.
tions prior to use. Specific precautions are listed in Section 8.
3.1.3 For other definitions of terms used in this test method,
1.4 This international standard was developed in accor-
refer to Terminology D4725.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Significance and Use
Development of International Standards, Guides and Recom-
4.1 This test method is based on the cold oxidation of the
mendations issued by the World Trade Organization Technical
glycerol by sodium metaperiodate in a strong acidic medium.
Barriers to Trade (TBT) Committee.
Formaldehyde and formic acid are produced in this reaction
and the latter is used to measure the glycerol content by
2. Referenced Documents
titration with standard sodium hydroxide solution, to a pH 8.1
2
2.1 ASTM Standards:
6 0.1. The glycerol content is expressed as a percentage
D1193 Specification for Reagent Water (m/m).
D4725 Terminology for Engine Coolants and Related Fluids
CH OH 2 CHOH 2 CH OH12 NaIO→ (1)
2 2 4
E177 Practice for Use of the Terms Precision and Bias in
HCOOH12 HCHO12 NaIO 1H O
ASTM Test Methods
3 2
E691 Practice for Conducting an Interlaboratory Study to
4.2 Interferences—The glycerin sample should be free of
Determine the Precision of a Test Method
organic compounds with more than two hydroxyl groups on
adjacent carbon atoms (for example, sugars, glycols). These
types of compounds may produce formic acid which interferes
1 with the determination of the glycerol content.
This test method is under the jurisdiction ofASTM Committee D15 on Engine
Coolants and Related Fluids and is the direct responsibility of Subcommittee
D15.04 on Chemical Properties.
Current edition approved Sept. 1, 2021. Published September 2021. Originally
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approved in 2010. Last previous edition approved in 2015 as D7637–10 (2015). Available from U.S. Pharmacopeial (USP), 12601 Twinbrook Parkway,
DOI: 10.1520/D7637-10R21. Rockville, MD 20852-1790, http://www.usp.org.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from American Oil Chemists’ Society (AOCS), 2710 S. Boulder,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Urbana, IL 61802-6996, http://www.aocs.org.
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Standards volume information, refer to the standard’s Document Summary page on AvailablefromTheBritishStandardsInstitution(BSI),389ChiswickHighRd.,
the ASTM website. London W4 4AL, U.K., http://www.bsigroup.com.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D7637 − 10 (2021)
5. Apparatus 7.9 Potassium Iodide, aqueous solution—Dissolve 16.5 g of
potassium iodide in water to make 100 mL. Store tightly
5.1 Burette—50 mL“TypeA” unit that can deliver 30 drops
capped in a light-resistant container.
per mL and calibrated to meet the National Institute of
Standards and Technology (NI
...