ASTM D7884-13

Standard Test Method for Determination of 4-Carboxybenzaldehyde and <emph type="bdit" >p</emph>-Toluic Acid in Purified Terephthalic Acid by Reverse Phase 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 imparts 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 for use as an internal quality control tool where these products are produced or are used.
SCOPE
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 reverse phase 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Jul-2013
• ICS: 71.080.40 - Organic acids
• Technical Committee: D16 - Aromatic, Industrial, Specialty and Related Chemicals
• Drafting Committee: D16.02 - Oxygenated Aromatics

Relations

• Referred By: ASTM D8062-23 - Standard Specification for Purified Terephthalic Acid (PTA) with Low <emph type="ital" >p</emph>-Toluic Acid
• Effective Date: 01-Aug-2013
• Referred By: ASTM D7976-14(2020) - Standard Specification for Purified Terephthalic Acid (PTA)
• Effective Date: 01-Aug-2013

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D7884 −13
Standard Test Method for
Determination of 4-Carboxybenzaldehyde and p-Toluic Acid
in Purified Terephthalic Acid by Reverse Phase High
1
Performance Liquid Chromatography
This standard is issued under the fixed designation D7884; 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 ASTM Test Methods
E682 Practice for Liquid Chromatography Terms and Rela-
1.1 This test method covers the determination of the
tionships
4-Carboxybenzaldehyde (4-CBA) and p-Toluic acid (p-TOL)
E691 Practice for Conducting an Interlaboratory Study to
in purified terephthalic acid (PTA) by reverse phase high
Determine the Precision of a Test Method
performance liquid chromatography (HPLC). This method is
3
2.2 ISO Document:
applicablefor4-CBAfrom2to500mg/kgandfor p-TOLfrom
EN ISO 8213 Chemical products for industrial use—
10 to 500 mg/kg, respectively.
Sampling techniques—Solid chemical products in the
1.2 In determining the conformance of the test results using
form of particles varying from powders to coarse lumps
4
thismethodtoapplicablespecification,resultsshallberounded
2.3 Other Document:
off in accordance with the rounding-off method of Practice
OSHA Regulations, 29 CFR paragraphs 1910.1000 and
E29.
1910.1200
1.3 The values stated in SI units are to be regarded as
3. Summary of Test Method
standard. No other units of measurement are included in this
3.1 Reverse Phase HPLC Method—PTAsampleisdissolved
standard.
in ammonium hydroxide solution, and a fixed volume of this
1.4 This standard does not purport to address all of the
solution is injected into a high performance liquid chromato-
safety concerns, if any, associated with its use. It is the
graph equipped with a UV detector.AC18 chemically bonded
responsibility of the user of this standard to establish appro-
column is used to separate the impurities 4-CBA and p-TOL
priate safety and health practices and determine the applica-
from PTA. The external standard calibration is used for
bility of regulatory limitations prior to use.
quantification.
2. Referenced Documents
4. Significance and Use
2
2.1 ASTM Standards:
4.1 The presence of 4-CBAand p-TOL in PTAused for the
D1193 Specification for Reagent Water
production of polyester is undesirable because they can slow
D4790 Terminology ofAromatic Hydrocarbons and Related
down the polymerization process and 4-CBA imparts color-
Chemicals
ation to the polymer due to thermal instability.
D6809 Guide for Quality Control and Quality Assurance
4.2 Determining the amount of 4-CBA and p-TOL remain-
Procedures for Aromatic Hydrocarbons and Related Ma-
ing from the manufacture of PTA is often required. This test
terials
method is suitable for setting specifications and for use as an
E29 Practice for Using Significant Digits in Test Data to
internal quality control tool where these products are produced
Determine Conformance with Specifications
or are used.
E177 Practice for Use of the Terms Precision and Bias in
5. Apparatus
1
This test method is under the jurisdiction of ASTM Committee D16 on 5.1 High Performance Liquid Chromatograph (HPLC)—
Aromatic Hydrocarbons and Related Chemicals and is the direct responsibility of
any HPLC capable of pumping the mobile phase at flow rates
Subcommittee D16.02 on Oxygenated Aromatics.
Current edition approved Aug. 1, 2013. Published October 2013. DOI: 10.1520/
3
D7884-13. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4th Floor, New York, NY 10036, http://www.ansi.org.
4
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Standards volume information, refer to the standard’s Document Summary page on 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
the ASTM website. www.access.gpo.gov.
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D7884−13
TABLE 1 Recommended Operating Conditions
of sufficiently high purity to permit its use without lessening
Column C18 the performance or accuracy of the determination. Reagent
Octadecylsilane chemically chemicals shall be used for all tests.
Stationary phase
bonded silica
NOTE 1—Calibration and detection limits of this test method can be
Particle size 5 µm
biased by the purity of the reagents.
Material of column stainless steel
Length of column 150 mm 6.2 Ammonium Hydroxide—25 to 28 %.
Inner diameter 4–5 mm
...