ASTM E1228-23

Standard Test Method for Assay of Peroxy Esters-Catalyzed Iodometric Procedure

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.
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.

General Information

• Status: Published
• Publication Date: 31-Mar-2023
• ICS: 71.080.70 - Esters
• Technical Committee: D16 - Aromatic, Industrial, Specialty and Related Chemicals
• Drafting Committee: D16.12 - Caustics and Peroxides

Relations

• Refers: ASTM E298-17a - Standard Test Methods for Assay of Organic Peroxides
• Effective Date: 01-Jul-2017
• Refers: ASTM E298-17 - Standard Test Methods for Assay of Organic Peroxides
• Effective Date: 01-Feb-2017
• Refers: ASTM D6809-02(2016) - Standard Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
• Effective Date: 01-Nov-2016
• Refers: ASTM E475-16 - Standard Test Method for Assay of Di-<emph type="bdit">tert</emph>-Butyl Peroxide Using Gas Chromatography
• Effective Date: 01-Apr-2016
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM E755-08 - Standard Test Method for Dicumyl Peroxide, Assay (Liquid Chromatography) (Withdrawn 2016)
• Effective Date: 15-Dec-2008
• Refers: ASTM E29-08 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-Oct-2008
• Refers: ASTM E691-08 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Oct-2008
• Refers: ASTM E298-08 - Standard Test Methods for Assay of Organic Peroxides
• Effective Date: 01-Apr-2008
• Refers: ASTM D6809-02(2007) - Standard Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
• Effective Date: 01-Jun-2007
• Refers: ASTM E29-06b - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 15-Nov-2006
• Refers: ASTM E29-06a - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 15-Sep-2006
• Refers: ASTM E29-06 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-May-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006

Overview

ASTM E1228-23: Standard Test Method for Assay of Peroxy Esters-Catalyzed Iodometric Procedure provides a precise and reliable method for determining the active oxygen content in organic peroxides of the peroxy ester type. Peroxy esters are important chemical intermediates, catalysts, and initiators widely used in industrial processes. This standard outlines a catalyzed iodometric procedure, ensuring consistency, quality, and safety in the analysis of peroxy esters, thereby confirming their suitability for intended applications.

Key Topics

• Assay of Peroxy Esters: Details a test method specifically for organic peroxides within the peroxy ester group, using a catalyzed iodometric procedure to determine active oxygen content.
• Reagents and Equipment: Specifies the use of reagent-grade chemicals and proper laboratory apparatus, including iodine flasks, beakers, burets, and a water bath maintained at precise temperatures for reproducible results.
• Procedural Controls: Emphasizes accuracy in reagent measurements, blank titrations for calibration, and precise sample weighing to minimize errors.
• Calculations and Reporting: Provides formulas for calculating assay values and active oxygen percentages, with guidelines for rounding off results per ASTM Practice E29.
• Safety and Quality Protocols: Highlights the importance of compliance with safety data sheets (SDS), OSHA regulations, and proper laboratory safety practices when handling organic peroxides and related chemicals. Quality assurance and interlaboratory comparisons are encouraged for validated results.

Applications

The ASTM E1228-23 standard is widely applicable in:

• Quality Control in Manufacturing: Ensures peroxy esters meet required assay specifications before being used as intermediates, catalysts, or initiators in polymerization and other chemical processes.
• Safety Compliance: Supports regulatory adherence by providing validated methods for determining active oxygen content, a critical factor in handling and transportation of organic peroxides.
• Research & Development: Assists laboratories developing new peroxy ester products by enabling accurate assessment of substance purity and performance characteristics.
• Comparative Analysis: Facilitates consistent results across different laboratories, fostering confidence between producers, suppliers, and customers regarding product specifications.

Related Standards

For comprehensive control and enhanced analytical coverage, related ASTM and regulatory documents include:

• ASTM E298 – Test Methods for Assay of Organic Peroxides
• ASTM E475 – Test Method for Assay of Di-tert-Butyl Peroxide Using Gas Chromatography
• ASTM E755 – Test Method for Dicumyl Peroxide, Assay (Liquid Chromatography)
• ASTM E29 – Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• ASTM E200 – Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
• ASTM D1193 – Specification for Reagent Water
• OSHA 29 CFR 1910.1000 and 1910.1200 – Air Contaminants and Hazard Communication regulations

Practical Value

Implementing ASTM E1228-23 brings significant benefits:

• Accuracy and Reproducibility: Well-defined procedures yield consistent, precise results.
• Safety Assurance: Reduces fire and explosion risk when analyzing reactive peroxy esters.
• International Recognition: Developed in accordance with World Trade Organization TBT guidelines, supporting global trade and compliance.
• Regulatory Alignment: Aligns laboratory practices with national and international safety and quality standards in the chemical industry.

By following ASTM E1228-23, organizations can confidently assess peroxy esters’ assay levels, improve product quality, and enhance workplace safety, meeting both operational and regulatory demands.

Keywords: peroxy esters, iodometric assay, active oxygen, ASTM E1228, organic peroxides, chemical analysis, quality control, safety standards

Standards Content (Sample)

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.
Designation: 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* D6809 Guide for Quality Control and Quality Assurance
Procedures for Aromatic Hydrocarbons and Related Ma-
1.1 This test method covers the assay of organic peroxides
terials
of the peroxy ester type.
E29 Practice for Using Significant Digits in Test Data to
NOTE 1—Other test methods for the assay of organic peroxides are
Determine Conformance with Specifications
given in Test Methods E298, E475, and E755.
E180 Practice for Determining the Precision of ASTM
1.2 Review the current safety data sheets (SDS) for detailed
Methods for Analysis and Testing of Industrial and Spe-
information concerning toxicity, first aid procedures, and safety
cialty Chemicals (Withdrawn 2009)
precautions.
E200 Practice for Preparation, Standardization, and Storage
of Standard and Reagent Solutions for Chemical Analysis
1.3 The values stated in SI units are to be regarded as the
standard. No other units of measurement are included in this E298 Test Methods for Assay of Organic Peroxides
E300 Practice for Sampling Industrial Chemicals
test method.
E475 Test Method for Assay of Di-tert-Butyl Peroxide
1.4 In determining the conformance of the test results using
Using Gas Chromatography
this method to applicable specifications, results shall be
E691 Practice for Conducting an Interlaboratory Study to
rounded off in accordance with the rounding-off method of
Determine the Precision of a Test Method
Practice E29.
E755 Test Method for Dicumyl Peroxide, Assay (Liquid
1.5 This standard does not purport to address all of the
Chromatography) (Withdrawn 2016)
safety concerns, if any, associated with its use. It is the
2.2 Other Documents:
responsibility of the user of this standard to establish appro-
OSHA Regulations, 29 CFR paragraphs 19100.1000 and
priate safety, health, and environmental practices and deter-
1910.1200 Air contaminates – table of exposure limits
mine the applicability of regulatory limitations prior to use.
and Hazard Communication
Specific hazards statements are given in Section 9.
1.6 This international standard was developed in accor-
3. Terminology
dance with internationally recognized principles on standard-
3.1 Definitions:
ization established in the Decision on Principles for the
3.1.1 active oxygen—the oxidizing power present in organic
Development of International Standards, Guides and Recom-
peroxides expressed as oxygen (equivalent weight 8.00).
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
2. Referenced Documents
4.1 A sample is dissolved in a mixture of isopropyl alcohol,
2.1 ASTM Standards:
acetic acid, and cupric chloride. A solution of potassium iodide
D1193 Specification for Reagent Water
is added and the mixture is briefly heated, then allowed to react
in the dark at room temperature for 30 min. The cupric ion
This test method is under the jurisdiction of ASTM Committee D16 on
catalyzes the reduction of the peroxide and the liberated iodine
Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-
is titrated with standard sodium thiosulfate solution.
bility of Subcommittee D16.12 on Caustics and Peroxides.
Current edition approved April 1, 2023. Published June 2023. Originally
approved in 1988. Last previous edition approved in 2017 as E1228 – 17. DOI:
10.1520/E1228-23. The last approved version of this historical standard is referenced on
For referenced ASTM standards, visit the ASTM website, www.astm.org, or www.astm.org.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from U.S. Government Printing Office, Superintendent of
Standards volume information, refer to the standard’s Document Summary page on Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
the ASTM website. www.access.gpo.gov.
*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
E1228 − 23
5. Significance and Use reducing agents and sources of heat, sparks, or open flames.
Reactivity varies widely and some compounds may explode
5.1 Peroxy esters are widely used as chemical
when shocked. Organic peroxides are irritating to the skin,
intermediates, catalysts, and initiators. This test method pro-
eyes, and mucous membranes. Avoid bodily contact and handle
vides a procedure for assaying peroxy esters to determine if
only in a well-ventilated area.
they are suitable for their intended use.
9.2 Consult current OSHA regulations and review the cur-
6. Interferences
rent Safety Data Sheets (SDS) for detailed information con-
6.1 Conjugated diolefins interfere under the conditions of
cerning toxicity, first aid procedures, handling, and safety
analysis by absorbing iodine.
precautions. Review local regulations for all materials used in
this test method.
7. Apparatus
10. Procedure
7.1 Iodine Flasks, 250 mL capacity, with stoppers.
10.1 Add 50 mL of isopropyl alcohol and 15 mL of acetic
NOTE 2—All glassware should be cleaned thoroughly with dichromate
acid to a 250 mL iodine flask. A graduate can be used for these
cleaning solution before use.
additions.
7.2 Beakers, 1 mL capacity, glass or PTFE.
10.2 Pipet 1.00 mL of 1 % cupric chloride solution into the
7.3 Buret, 50 mL capacity, graduated in 0.1 mL subdivi-
flask. (Warning—The quantity of the cupric chloride catalyst
sions.
solution must be carefully measured in order to obtain repro-
7.4 Water Bath, maintained at 60 °C.
ducible results as the reagent also reacts with iodide to liberate
iodine according to the following Eq 1:
8. Reagents
2Cu 14I 2 →2 CuI1I (1)
8.1 Purity of Reagents—Reagent grade chemicals shall be
The blank titration should be approximately 1.0 mL. The results should
used in all tests. Unless otherwise indicated, it is intended that
be discarded and the analysis repeated if a significantly higher blank
all reagents shall conform to the Specifications of the Com-
value is obtained.)
mittee on Analytical Reagents of the American Chemical
10.3 Sparge the solution with a rapid flow of nitrogen for
Society, where such specifications are available. Other grades
2 min, then stopper the flask and reserve.
may be used, provided it is first ascertained that the reagent is
10.4 Accurately weigh a sample containing 3 meq to 4 meq
of sufficiently high purity to permit its use without lessening
of active oxygen in a 1 mL beaker. Transfer the beaker
the accuracy of the determination.
containing the sample to the prepared flask and immediately
8.2 Purity of Water—Unless otherwise indicated, references
restopper and mix. The approximate sample weight may be
to water shall be understood to mean Type I or II reagent water
calculated as follows:
conforming to Specification D1193.
3.5 M
Sample mass, g 5 (2)
8.3 Acetic Acid, glacial.
2C × 1000
8.4 Isopropyl Alcohol.
where:
8.5 Hydrochloric Acid, (1:100)—Dilute 1.0 mL of concen-
M = molecular weight of compound, and
trated hydrochloric acid (HCl) to 100 mL with water.
C = number of peroxide groups in the molecule.
NOTE 3—Volatile liquid peroxides may be diluted to a known volume
8.6 Cupric Chloride Solution, 1 %—Dilute 1.0 g of anhy-
with isopropyl alcohol and aliquots taken for analysis.
drous cupric chloride (CuCl ) to 100 mL with water. Add
10.5 While maintaining a flow of nitrogen over the solution,
1.0 mL of 1:100 HCl and mix. The solution should be clear.
add 5 mL (graduate) of freshly prepared
...

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 [e-mail]. 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
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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
...