ASTM D4471-22

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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: D4471 − 18 D4471 − 22
Standard Test Method for
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Pyridine Bases in Cresylic Acid by Direct Titration
This standard is issued under the fixed designation D4471; 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*
1.1 This test method covers the determination of pyridine and other basic nitrogen impurities in crude and refined cresylic acids
streams, including mixtures.
1.2 This test method is applicable for pyridine base levels of 0.001 % to 0.5 %.
1.3 In determining the conformance of the test results using this method to applicable specifications, results shall be rounded off
in accordance with the rounding-off method of Practice E29.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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. For specific hazard statements, see Section 8.
1.6 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
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2.1 ASTM Standards:
D3852 Practice for Sampling and Handling Phenol, Cresols, and Cresylic Acid
D4790 Terminology of Aromatic Hydrocarbons and Related Chemicals
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
2.2 Other Document:
OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.1200 paragraphs 1910.1000 and 1910.1200Air Contaminates –
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Table of Exposure Limits and Hazard Communication
3. Terminology
3.1 For definitions of terms used in this test method see Terminology D4790.
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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 June 1, 2018May 1, 2022. Published July 2018June 2022. Originally approved in 1985. Last previous edition approved in 20102018 as
D4471 – 10.D4471 – 18. DOI: 10.1520/D4471-18.10.1520/D4471-22.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.
*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
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D4471 − 22
4. Summary of Test Method
4.1 This test method is a direct, nonaqueous titration technique utilizing perchloric acid in acetic acid as titrant and the cresylic
acid itself as titration solvent. Endpoints may be established potentiometrically as well as by indicator so that the method is
applicable to highly colored as well as lighter colored materials. This test method will detect basic components other than pyridine
bases should they be present. All basic compounds detected by this procedure are calculated and expressed as percent pyridine.
5. Significance and Use
5.1 The pyridine base content of cresylic acids is important in certain applications. This test method may be used as a tool for
quality control and specification purposes by producers and users.
6. Apparatus
6.1 Titrimeter or pH meter, equipped with half cell or combination glass pH and Ag/AgCl reference electrodes. The pair of
electrodes shall be mounted to extend well below the liquid level. Storage in water between titrations is essential because prolonged
immersion in nonaqueous medium significantly deadens response.
6.2 Buret, 5
...