ASTM E324-23

Standard Test Method for Relative Initial and Final Melting Points and the Melting Range of Organic Chemicals

SIGNIFICANCE AND USE
5.1 It has long been recognized that narrow melting range and high final melting point are good indications of high purity in crystalline organic compounds. Several ASTM test methods use these criteria to assay the purity of organic compounds (Note 1).
Note 1: Other ASTM test methods using melting (or freezing point) data to indicate sample purity are Test Methods D852 and D6875.  
5.2 The relatively simple and rapid test prescribed in this test method shows the sample under test to be either more or less pure than the standard sample. For specification purposes, a minimum allowable purity can be assured by setting limits on the differences in final melting points and the melting ranges between the standard sample and the sample under test.
SCOPE
1.1 This test method covers the determination, by a capillary tube method, of the initial melting point and the final melting point, which define the melting range, of samples of organic chemicals whose melting points without decomposition fall between 30 °C and 250 °C.  
1.2 This test method is applicable only to crystalline materials that are sufficiently stable in storage to met the requirements of a satisfactory standard sample as defined in Section 7.  
1.3 This test method is not directly applicable to opaque materials or to noncrystalline materials such as waxes, fats, and fatty acids.  
1.4 Review the current Safety Data Sheets (SDS) for detailed information concerning toxicity, first aid procedures, handling, and safety precautions.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 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.  
1.7 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-Mar-2023
• ICS: 19.040 - Environmental testing
• ICS: 71.080.01 - Organic chemicals in general
• Technical Committee: D16 - Aromatic, Industrial, Specialty and Related Chemicals
• Drafting Committee: D16.04 - Instrumental Analysis

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: E324 − 23
Standard Test Method for
Relative Initial and Final Melting Points and the Melting
1
Range of Organic Chemicals
This standard is issued under the fixed designation E324; 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 U.S. Department of Defense.
1. Scope* 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method covers the determination, by a capil-
D852 Test Method for Solidification Point of Benzene
lary tube method, of the initial melting point and the final
D6809 Guide for Quality Control and Quality Assurance
melting point, which define the melting range, of samples of
Procedures for Aromatic Hydrocarbons and Related Ma-
organic chemicals whose melting points without decomposi-
terials
tion fall between 30 °C and 250 °C.
D6875 Test Method for Solidification Point of Industrial
1.2 This test method is applicable only to crystalline mate-
Organic Chemicals by Thermistor
rials that are sufficiently stable in storage to met the require-
E1 Specification for ASTM Liquid-in-Glass Thermometers
ments of a satisfactory standard sample as defined in Section 7.
E11 Specification for Woven Wire Test Sieve Cloth and Test
Sieves
1.3 This test method is not directly applicable to opaque
E1547 Terminology Relating to Industrial and Specialty
materials or to noncrystalline materials such as waxes, fats, and
Chemicals
fatty acids.
1.4 Review the current Safety Data Sheets (SDS) for de-
3. Terminology
tailed information concerning toxicity, first aid procedures,
3.1 Definitions:
handling, and safety precautions.
3.1.1 See Terminology E1547 for definition of terms used in
1.5 The values stated in SI units are to be regarded as
this test method.
standard. No other units of measurement are included in this
3.1.2 initial melting point, n—the temperature at which
standard.
positive evidence of liquefaction is observed (see 9.4.1).
1.6 This standard does not purport to address all of the 3.1.3 final melting point, n—the temperature at which the
last crystal disappears into the melt.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Summary of Test Method
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4.1 This test method determines initial and final melting
1.7 This international standard was developed in accor- points by a relative procedure, utilizing a standard sample that
dance with internationally recognized principles on standard- has been assigned jointly accepted melting point values by the
ization established in the Decision on Principles for the
concerned parties (such as a supplier and a consumer, or NIST
Development of International Standards, Guides and Recom- and a manufacturer). The absolute values of the initial and final
mendations issued by the World Trade Organization Technical
melting points are not critical factors, as long as the producer
Barriers to Trade (TBT) Committee. and consumer agree to use the standard sample and its
empirically assigned values as the basis for testing and
specifications agreements. Simultaneous readings are taken of
1
This test method is under the jurisdiction of ASTM Committee D16 on
Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-
2
bility of Subcommittee D16.04 on Instrumental Analysis. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2023. Published April 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1967. Last previous edition approved in 2016 as E324 – 16. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0324-23. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E324 − 23
these temperatures for an unknown and the agreed standard made by the same industrial process. Significant deviations
sample of the same chemical; the respective initial melting from identity in chemical composition lead to some loss of
points and the respective final melting points are recorded. The precision.
differences
...

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: E324 − 16 E324 − 23
Standard Test Method for
Relative Initial and Final Melting Points and the Melting
1
Range of Organic Chemicals
This standard is issued under the fixed designation E324; 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 U.S. Department of Defense.
1. Scope Scope*
1.1 This test method covers the determination, by a capillary tube method, of the initial melting point and the final melting point,
which define the melting range, of samples of organic chemicals whose melting points without decomposition fall between 30 and
250°C.30 °C and 250 °C.
1.2 This test method is applicable only to crystalline materials that are sufficiently stable in storage to met the requirements of a
satisfactory standard sample as defined in Section 77.
1.3 This test method is not directly applicable to opaque materials or to noncrystalline materials such as waxes, fats, and fatty
acids.
1.4 Review the current Safety Data Sheets (SDS) for detailed information concerning toxicity, first aid procedures, handling, and
safety precautions.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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.
1.7 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D852 Test Method for Solidification Point of Benzene
3
D1015 Test Method for Freezing Points of High-Purity Hydrocarbons (Withdrawn 2019)
3
D1016 Test Method for Purity of Hydrocarbons from Freezing Points (Withdrawn 2019)
1
This practice test method is under the jurisdiction of ASTM Committee D16 on Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsibility
of Subcommittee D16.04 on Instrumental Analysis.
Current edition approved Nov. 1, 2016April 1, 2023. Published November 2016April 2023. Originally approved in 1967. Last previous edition approved in 19992016 as
E324 – 99 which was withdrawn April 2001 and reinstated in November 2016. DOI: 10.1520/E0324-16.16. DOI: 10.1520/E0324-23.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E324 − 23
3
D1493 Test Method for Solidification Point of Industrial Organic Chemicals (Withdrawn 2004)
D1982 Test Method for Titer of Fatty Acids
D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
D6875 Test Method for Solidification Point of Industrial Organic Chemicals by Thermistor
E1 Specification for ASTM Liquid-in-Glass Thermometers
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
3
(Withdrawn 2009)
E1547 Terminology Relating to Industrial and Specialty Chemicals
3. Terminology
3.1 Definitions:
3.1.1 See Terminology E1547 for definition of terms used in this test method.
3.1.2 initial melting point, n—the temperature at which positive evidence of liquefaction is observed (see 9.4.1).
3.1.3 final melting point, n—the temperature at which the last crystal disappears into the melt.
4. Summary of Test Method
4.1 1 This test method determines initial and final melting points by a relative procedure, utilizing a standard sample that has been
assigned jointly accepted melting
...