ASTM D7883-20

Standard Test Method for Determination of 4-Carboxybenzaldehyde and <emph type="bdit" >p</emph>-Toluic Acid in Purified Terephthalic Acid by Weak Anion Exchange High Performance Liquid Chromatography

SIGNIFICANCE AND USE
4.1 The presence of 4-CBA and p-TOL in PTA used for the production of polyester is undesirable because they can slow down the polymerization process, and 4-CBA is also imparting coloration to the polymer due to thermal instability.  
4.2 Determining the amount of 4-CBA and p-TOL remaining from the manufacture of PTA is often required. This test method is suitable for setting specifications and could be used as an internal quality control tool where these products are produced or are used.
SCOPE
1.1 This test method2 covers the determination of the 4-Carboxybenzaldehyde (4-CBA) and p-Toluic acid (p-TOL) in purified terephthalic acid (PTA) by weak anion exchange high performance liquid chromatography (HPLC). This method is applicable for 4-CBA from 2 to 500 mg/kg and for p-TOL from 10 to 500 mg/kg, respectively.  
1.2 In determining the conformance of the test results using this method to applicable specification, results shall be rounded off in accordance with the rounding-off method of Practice E29.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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.  
1.5 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-Sep-2020
• ICS: 71.080.40 - Organic acids
• Technical Committee: D16 - Aromatic, Industrial, Specialty and Related Chemicals
• Drafting Committee: D16.02 - Oxygenated Aromatics

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:D7883 −20
Standard Test Method for
Determination of 4-Carboxybenzaldehyde and p-Toluic Acid
in Purified Terephthalic Acid by Weak Anion Exchange High
1
Performance Liquid Chromatography
This standard is issued under the fixed designation D7883; 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. Referenced Documents
2 3
1.1 This test method covers the determination of the 2.1 ASTM Standards:
4-Carboxybenzaldehyde (4-CBA) and p-Toluic acid (p-TOL) D1193 Specification for Reagent Water
in purified terephthalic acid (PTA) by weak anion exchange D6809 Guide for Quality Control and Quality Assurance
high performance liquid chromatography (HPLC). This Procedures for Aromatic Hydrocarbons and Related Ma-
method is applicable for 4-CBA from 2 to 500 mg/kg and for terials
p-TOL from 10 to 500 mg/kg, respectively. E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
1.2 In determining the conformance of the test results using
E682 Practice for Liquid Chromatography Terms and Rela-
thismethodtoapplicablespecification,resultsshallberounded
tionships
off in accordance with the rounding-off method of Practice
E691 Practice for Conducting an Interlaboratory Study to
E29.
Determine the Precision of a Test Method
4
1.3 The values stated in SI units are to be regarded as
2.2 ISO Document:
standard. No other units of measurement are included in this
EN ISO 8213 Chemical products for industrial use—
standard.
Sampling techniques—Solid chemical products in the
1.4 This standard does not purport to address all of the form of particles varying from powders to coarse lumps
5
safety concerns, if any, associated with its use. It is the
2.3 Other Document:
responsibility of the user of this standard to establish appro-
OSHA Regulations, 29 CFR paragraphs 1910.1000 and
priate safety, health, and environmental practices and deter- 1910.1200
mine the applicability of regulatory limitations prior to use.
3. Summary of Test Method
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3.1 Weak Anion Exchange HPLC Method—PTA sample is
ization established in the Decision on Principles for the
dissolved in ammonium hydroxide solution. After pH
Development of International Standards, Guides and Recom-
adjustment, a fixed volume of this solution is injected into a
mendations issued by the World Trade Organization Technical
high performance liquid chromatograph equipped with a UV
Barriers to Trade (TBT) Committee.
detector. An anion-exchange column is used to separate the
impurities 4-CBAand p-TOLfrom PTA.The external standard
calibration is used for quantification.
1
This test method is under the jurisdiction of ASTM Committee D16 on
Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-
3
bility of Subcommittee D16.02 on Oxygenated Aromatics. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2020. Published December 2020. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2013. Last previous edition approved in 2019 as D7883 – 19. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7883-20. the ASTM website.
2 4
This standard is based on SH/T 1612.7-1995 Purified terephthalic acid for Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
industrial use—determination of p-Toluic Acid, 4-Carboxybenzaldehyde-HPLC, 4th Floor, New York, NY 10036, http://www.ansi.org.
5
copyright SINOPEC, 22 Chaoyangmen North Street, Chaoyang District, Beijing, AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
China 100728. A copy of SH/T 1612.7-1995 may be obtained from China 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
Petrochemical Press, www.sinopec-press.com. www.access.gpo.gov.
*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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D7883−20
4. Significance and Use 5.8 pH Meter.
4.1 The presence of 4-CBAand p-TOL in PTAused for the 5.9 Sample Filter—A disposable syringe filter made of
production of polyester is undesirable because they can slow cellulose acetate, wi
...

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: D7883 − 19 D7883 − 20
Standard Test Method for
Determination of 4-Carboxybenzaldehyde and p-Toluic Acid
in Purified Terephthalic Acid by Weak Anion Exchange High
1
Performance Liquid Chromatography
This standard is issued under the fixed designation D7883; 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
1.1 This test method covers the determination of the 4-Carboxybenzaldehyde (4-CBA) and p-Toluic acid (p-TOL) in purified
terephthalic acid (PTA) by weak anion exchange high performance liquid chromatography (HPLC). This method is applicable for
4-CBA from 2 to 500 mg/kg and for p-TOL from 10 to 500 mg/kg, respectively.
1.2 In determining the conformance of the test results using this method to applicable specification, results shall be rounded off
in accordance with the rounding-off method of Practice E29.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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.
1.5 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
3
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E682 Practice for Liquid Chromatography Terms and Relationships
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
4
2.2 ISO Document:
EN ISO 8213 Chemical products for industrial use—Sampling techniques—Solid chemical products in the form of particles
varying from powders to coarse lumps
1
This test method is under the jurisdiction of ASTM Committee D16 on Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsibility of
Subcommittee D16.02 on Oxygenated Aromatics.
Current edition approved Nov. 1, 2019Oct. 1, 2020. Published December 2019December 2020. Originally approved in 2013. Last previous edition approved in 20132019
as D7883 – 13.D7883 – 19. DOI: 10.1520/D7883-19.10.1520/D7883-20.
2
This standard is based on SH/T 1612.7-1995 Purified terephthalic acid for industrial use—determination of p-Toluic Acid, 4-Carboxybenzaldehyde-HPLC, copyright
SINOPEC, 22 Chaoyangmen North Street, Chaoyang District, Beijing, China 100728. A copy of SH/T 1612.7-1995 may be obtained from China Petrochemical Press,
www.sinopec-press.com.
3
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.
4
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*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 ----------------------
D7883 − 20
5
2.3 Other Document:
OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.1200
3. Summary of Test Method
3.1 Weak Anion Exchange HPLC Method—PTA sample is dissolved in ammonium hydroxide solution. After pH adjustment, a
fixed volume of this solution is injected into a high performance liquid chromatograph equipped with a UV detector. An
anion-exchange column is used to separate the impurities 4-CBA and p-TOL from PTA. The external standard calibration is used
for quantification.
4. Significance and Use
4.1 The presence of 4-CBA and p-TOL in PTA used for the production of polyester is undesirable because they can slow down
the polymerization process, and 4-CBA is also impart
...