ASTM D8031-16 PDF

Scope: 5.1 An estimate of TA purity can be determined by titrating with KOH. As an index of TA purity, the acid number can be used as a guide in the quality control of TA production.

1.1 This test method covers the determination of acid number in terephthalic acid (TA) by automatic potentiometric titration. As the index of TA purity, acid number is usually within 674 to 676 mg KOH/g.

1.2 In determining the conformance of the test results using this method, 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 D8031-16 Referenced Document

ASTM D1193 Standard Specification for Reagent Water
ASTM D4790 Standard Terminology of Aromatic Hydrocarbons and Related Chemicals
ASTM D664 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
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 E300 Standard Practice for Sampling Industrial Chemicals
ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

2016 ASTM D8031-16 Standard Test Method for Acid Number of Terephthalic Acid (TA) by Automatic Potentiometric Titration