ASTM E1228-23

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: E1228 − 17 E1228 − 23
Standard Test Method for
Assay of Peroxy Esters—Catalyzed Iodometric Procedure
This standard is issued under the fixed designation E1228; 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 assay of organic peroxides of the peroxy ester type.
NOTE 1—Other test methods for the assay of organic peroxides are given in Test Methods E298, E475, and E755.
1.2 Review the current safety data sheets (SDS) for detailed information concerning toxicity, first aid procedures, and safety
precautions.
1.3 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this test method.
1.4 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.
1.5 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. Specific hazards statements are given in Section 9.
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
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
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
(Withdrawn 2009)
E200 Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
E298 Test Methods for Assay of Organic Peroxides
E300 Practice for Sampling Industrial Chemicals
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 D16.12 on Caustics and Peroxides.
Current edition approved June 1, 2017April 1, 2023. Published July 2017June 2023. Originally approved in 1988. Last previous edition approved in 20092017 as
E1228 – 09.E1228 – 17. DOI: 10.1520/E1228-17.10.1520/E1228-23.
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.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
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E1228 − 23
E475 Test Method for Assay of Di-tert-Butyl Peroxide Using Gas Chromatography
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E755 Test Method for Dicumyl Peroxide, Assay (Liquid Chromatography) (Withdrawn 2016)
2.2 Other Documents:
OSHA Regulations, 29 CFR paragraphs 19100.1000 and 1910.1200 Air contaminates – table of exposure limits and Hazard
Communication
3. Terminology
3.1 Definitions:
3.1.1 active oxygen—the oxidizing power present in organic peroxides expressed as oxygen (equivalent weight 8.00).
4. Summary of Test Method
4.1 A sample is dissolved in a mixture of isopropyl alcohol, acetic acid, and cupric chloride. A solution of potassium iodide is
added and the mixture is briefly heated, then allowed to react in the dark at room temperature for 30 min. The cupric ion catalyzes
the reduction of the peroxide and the liberated iodine is titrated with standard sodium thiosulfate solution.
5. Significance and Use
5.1 Peroxy esters are widely used as chemical intermediates, catalysts, and initiators. This test method provides a procedure for
assaying peroxy esters to determine if they are suitable for their intended use.
6. Interferences
6.1 Conjugated diolefins interfere under the conditions of analysis by absorbing iodine.
7. Apparatus
7.1 Iodine Flasks, 250-mL250 mL capacity, with stoppers.
NOTE 2—All glassware should be cleaned thoroughly with dichromate cleaning solution before use.
7.2 Beakers, 1-mL1 mL capacity, glass or PTFE.
7.3 Buret, 50-mL50 mL capacity, graduated in 0.1-mL0.1 mL subdivisions.
7.4 Water Bath, maintained at 60°C.60 °C.
8. Reagents
8.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the Specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
8.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean Type II or IIII or II reagent water
conforming to Specification D1193.
8.3 Acetic Acid, glacial.
Available from U.S. Government Printing Office, Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://www.access.gpo.gov.
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for
Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC),
Rockville, MD.
E1228 − 23
8.4 Isopropyl Alcohol.
8.5 Hydrochloric Acid, (1:100)—Dilute 1.0 mL of concentrated hydrochloric acid (HCl) to 100 mL with water.
8.6 Cupric Chloride Solution, 1 %—Dilute 1.0 g of anhydrous cupric chloride (CuCl ) to 100 mL with water. Add 1.0 mL 1.0 mL
of 1:100 HCl and mix. The solution should be clear.
8.7 Potassium Iodide Solution, 50 %—Dissolve 25 g 25 g of potassium iodide (KI) in 25 mL 25 mL of de-aerated water. This
reagent should be freshly prepared just prior to use.
8.8 Sodium Thiosulfate Standard Solution, (0.1 meq/mL)—Prepare and standardize in accordance with the appropriate sections of
Practice E200.
8.9 Nitrogen Gas, oxygen-free.
9. Hazards
9.1 Organic peroxides are strong oxidizing agents and present potential fire and explosion hazards. Avoid contact with reducing
agents and sources of heat, sparks, or open flames. Reactivity varies widely and some compounds may explode when shocked.
Organic peroxides are irritating to the skin, eyes, and mucous membranes. Avoid bodily contact and handle only in a
well-ventilated area.
9.2 Consult current OSHA regulations and review the current Safety Data Sheets (SDS) for detailed information concerning
toxicity, first aid procedures, handling, and safety precautions. Review local regulations for all materials used in this test method.
10. Procedure
10.1 Add 50 mL of isopropyl alcohol and 15 mL of acetic acid to a 250-mL250 mL iodine flask. A graduate can be used for these
additions.
10.2 Pipet 1.00 mL of 1 % cupric chloride solution into the flask. (Warning—The quantity of the cupric chloride catalyst solution
must be carefully measured in order to obtain reproducible
...