ASTM D7884-13 PDF

Scope: 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.

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.

ASTM D7884-13 Referenced Document

ASTM D1193 Standard Specification for Reagent Water
ASTM D4790 Standard Terminology of Aromatic Hydrocarbons and Related Chemicals
ASTM D6809 Standard Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
ASTM E177 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
ASTM E29 Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
ASTM E682 Standard Practice for Liquid Chromatography Terms and Relationships
ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

2024 ASTM D7884-24 Standard Test Method for Determination of 4-Carboxybenzaldehyde and p-Toluic Acid in Purified Terephthalic Acid by Reverse Phase High Performance Liquid Chromatography
2023 ASTM D7884-23 Standard Test Method for Determination of 4-Carboxybenzaldehyde and p-Toluic Acid in Purified Terephthalic Acid by Reverse Phase High Performance Liquid Chromatography
2020 ASTM D7884-20 Standard Test Method for Determination of 4-Carboxybenzaldehyde and p-Toluic Acid in Purified Terephthalic Acid by Reverse Phase High Performance Liquid Chromatography
2019 ASTM D7884-19 Standard Test Method for Determination of 4-Carboxybenzaldehyde and p-Toluic Acid in Purified Terephthalic Acid by Reverse Phase High Performance Liquid Chromatography
2013 ASTM D7884-13 Standard Test Method for Determination of 4-Carboxybenzaldehyde and p-Toluic Acid in Purified Terephthalic Acid by Reverse Phase High Performance Liquid Chromatography