ASTM D1492-21

Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration

SIGNIFICANCE AND USE
5.1 This test method is useful as an internal quality control tool, and for use in development or research work on industrial aromatic hydrocarbons and related materials. This test method gives a broad indication of olefinic content. It will not differentiate between the types of aliphatic unsaturation.
SCOPE
1.1 This test method covers the determination of Bromine Index in aromatic hydrocarbons, their derivatives, and related chemicals.  
1.2 This test method is applicable to samples with Bromine Index concentrations to 100 Bromine Index. The limit of detection (LOD) is for 1.5 Bromine Index and the limit of quantitation (LOQ) is 4.9 Bromine Index.
Note 1: LOD and LOQ were calculated using data from the D16 PTP program. This estimate of LOD includes within-lab variability.  
1.3 The following applies for the purposes of determining the conformance of the test results using this test 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2021
• ICS: 71.080.15 - Aromatic hydrocarbons
• Technical Committee: D16 - Aromatic, Industrial, Specialty and Related Chemicals
• Drafting Committee: D16.04 - Instrumental Analysis

Relations

• 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 D5776-14 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 15-Feb-2014
• Refers: ASTM D5776-13 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 15-Jul-2013
• 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 D5776-07(2012) - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 01-Jan-2012
• 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 D3437-11 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 01-Jan-2011
• Refers: ASTM D3437-10 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 01-Jun-2010
• Refers: ASTM D891-09 - Standard Test Methods for Specific Gravity, Apparent, of Liquid Industrial Chemicals (Withdrawn 2018)
• Effective Date: 01-Apr-2009
• 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 E29-08 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-Oct-2008
• Refers: ASTM D3437-08 - Standard Practice for Sampling and Handling Liquid Cyclic Products
• Effective Date: 01-Jun-2008
• Refers: ASTM D5776-07e1 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 01-Aug-2007
• Refers: ASTM D5776-07 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 01-Aug-2007
• 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

Overview

ASTM D1492-21: Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration is a key international standard developed by ASTM for the chemical analysis of aromatic hydrocarbons. This method provides a reliable, precise approach for the determination of the bromine index, which broadly indicates the olefinic content in aromatic hydrocarbons, their derivatives, and related materials. The method uses coulometric titration to measure the amount of bromine-reactive materials, supporting both routine quality control and industrial research.

The bromine index is defined as the number of milligrams of bromine consumed by 100 grams of sample under specified test conditions (mg-Br/100 g). This measurement is crucial for monitoring unsaturated compounds in hydrocarbons, ensuring product quality, and meeting industry regulations.

Key Topics

• Test Scope and Applicability

  • Designed for aromatic hydrocarbons, derivatives, and related chemicals.
  • Applicable to samples with bromine index concentrations up to 100; detection and quantitation limits are 1.5 and 4.9, respectively.
  • Especially relevant for samples containing only trace levels of olefins.

• Coulometric Titration Method

  • A specimen is dissolved in a solvent and titrated with electrolytically generated bromine at room temperature.
  • The titration uses an automatic amperometric-coulometric apparatus, providing accuracy and repeatability.
  • The end point is determined by a dead-stop method; titration time correlates with the amount of bromine consumed.

• Significance in Quality Control

  • The method supports internal quality control, product specification compliance, and research work.
  • It provides a broad indication of the olefinic (unsaturated) content but does not distinguish between types of aliphatic unsaturation.

• Precision and Quality Assurance

  • The standard specifies protocols for interlaboratory comparisons and repeatability checks, ensuring data reliability.
  • Laboratories are encouraged to implement statistical quality control practices in line with ASTM D6809.

Applications

ASTM D1492-21 is widely used in industries where aromatic hydrocarbons are manufactured, processed, or analyzed, including petrochemicals and industrial chemistry. Practical applications include:

• Routine Product Testing: Ensures that batches of aromatic hydrocarbons meet regulatory and customer specifications for unsaturated compound content.
• Process Control: Monitors the efficiency of purification and production processes by tracking changes in bromine-reactive materials.
• Research and Development: Supports the development of new chemical products by providing data on the olefinic content of experimental materials.
• Quality Control Programs: Provides critical data for quality assurance units, helping to maintain consistent product quality and regulatory compliance.

Related Standards

Organizations seeking to implement or supplement ASTM D1492-21 may also consider the following referenced ASTM standards:

• ASTM D891 - Test Methods for Specific Gravity of Liquid Industrial Chemicals
• ASTM D1159 - Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins
• ASTM D1491 - Test for Bromine Index of Aromatic Hydrocarbons by Potentiometric Titration (Withdrawn)
• ASTM D2710 - Test Method for Bromine Index of Petroleum Hydrocarbons by Electrometric Titration
• ASTM D3437 - Practice for Sampling and Handling Liquid Cyclic Products
• ASTM D4052 - Test Method for Density and API Gravity of Liquids by Digital Density Meter
• ASTM D5776 - Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• ASTM D6809 - Guide for Quality Control and Assurance Procedures for Aromatic Hydrocarbons and Related Materials
• ASTM E29 - Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

Keywords: bromine index, aromatic hydrocarbons, coulometric titration, industrial chemicals, ASTM D1492-21, quality control, unsaturated compounds, laboratory analysis, petrochemical testing.

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: D1492 − 21
Standard Test Method for
Bromine Index of Aromatic Hydrocarbons by Coulometric
Titration
This standard is issued under the fixed designation D1492; 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* 2. Referenced Documents
1.1 This test method covers the determination of Bromine 2.1 ASTM Standards:
D891 Test Methods for Specific Gravity, Apparent, of Liquid
Index in aromatic hydrocarbons, their derivatives, and related
Industrial Chemicals
chemicals.
D1193 Specification for Reagent Water
1.2 This test method is applicable to samples with Bromine
D3437 Practice for Sampling and Handling Liquid Cyclic
Index concentrations to 100 Bromine Index. The limit of
Products
detection (LOD) is for 1.5 Bromine Index and the limit of
D3505 Test Method for Density or Relative Density of Pure
quantitation (LOQ) is 4.9 Bromine Index.
Liquid Chemicals (Withdrawn 2023)
D4052 Test Method for Density, Relative Density, and API
NOTE 1—LOD and LOQ were calculated using data from the D16 PTP
Gravity of Liquids by Digital Density Meter
program. This estimate of LOD includes within-lab variability.
D5776 Test Method for Bromine Index of Aromatic Hydro-
1.3 The following applies for the purposes of determining
carbons by Electrometric Titration
the conformance of the test results using this test method to
D6809 Guide for Quality Control and Quality Assurance
applicable specifications, results shall be rounded off in accor-
Procedures for Aromatic Hydrocarbons and Related Ma-
dance with the rounding-off method of Practice E29.
terials
E29 Practice for Using Significant Digits in Test Data to
1.4 The values stated in SI units are to be regarded as
Determine Conformance with Specifications
standard. No other units of measurement are included in this
E691 Practice for Conducting an Interlaboratory Study to
standard.
Determine the Precision of a Test Method
1.5 This standard does not purport to address all of the
2.2 Other Document:
safety concerns, if any, associated with its use. It is the
OSHA Regulations, 29 CFR paragraphs 1910.1000 and
responsibility of the user of this standard to establish appro-
1910.1200
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3. Terminology
For specific hazard statements, see Section 8.
3.1 Definitions:
1.6 This international standard was developed in accor-
3.1.1 bromine index (B), n—the number of milligrams (mg)
dance with internationally recognized principles on standard-
of bromine consumed by 100 g of sample under given
ization established in the Decision on Principles for the
conditions (mg-Br/100 g).
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
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
This test method is under the jurisdiction of ASTM Committee D16 on the ASTM website.
Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsi- The last approved version of this historical standard is referenced on
bility of Subcommittee D16.04 on Instrumental Analysis. www.astm.org.
Current edition approved Nov. 1, 2021. Published January 2022. Originally Available from U.S. Government Printing Office Superintendent of Documents,
approved in 1957. Last previous edition approved in 2013 as D1492 – 13. DOI: 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
10.1520/D1492-21. 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
D1492 − 21
FIG. 1 Automatic Amperometric-Coulometric Titrator Circuit
4. Summary of Test Method tee on Analytical Reagents of the American Chemical Society,
where such specifications are available. Other grades may be
4.1 The specimen is added to a solvent and titrated with
used, provided it is first ascertained that the reagent is of
electrolytically generated bromine at room temperature. The
sufficiently high purity to permit its use without lessening the
end point is determined by a dead-stop method. The time of
accuracy of the determination.
titration is proportional to the bromine added to the specimen.
7.2 Purity of Water—Unless otherwise indicated, references
5. Significance and Use
to water shall be understood to mean reagent water conforming
to Type I or Type II of Specification D1193.
5.1 This test method is useful as an internal quality control
tool, and for use in development or research work on industrial
7.3 Electrolyte:
aromatic hydrocarbons and related materials. This test method
7.3.1 Preparation Cell Electrolyte—To make 1 L, mix
gives a broad indication of olefinic content. It will not
600 mL of glacial acetic acid, 260 mL of absolute methanol,
differentiate between the types of aliphatic unsaturation.
and 140 mL of KBr solution (119g/L).
7.4 Potassium Bromide Solution (119 g/L)—Dissolve 119 g
6. Apparatus
of potassium bromide (KBr) in water and dilute to 1 L.
6.1 Amperometric-Coulometric Apparatus, automatic, suit-
able for bromine index titrations with variable generator
8. Hazards
current and timer. A typical circuit diagram of suitable equip-
8.1 Consult current OSHA regulations, supplier’s Safety
ment is shown in Fig. 1.
Data Sheets, and local regulations for all materials used in this
6.2 Syringe, 2 mL with needle and rubber cap seal.
test method.
6.3 Stirrer, magnetic.
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
7. Reagents
Standard-Grade Reference Materials, American Chemical Society, Washington,
DC. For suggestions on the testing of reagents not listed by the American Chemical
7.1 Purity of Reagent—Reagent grade chemicals shall be
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
used in all tests. Unless otherwise indicated, it is intended that
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
all reagents shall conform to the specifications of the Commit- copeial Convention, Inc. (USPC), Rockville, MD.
D1492 − 21
9. Sampling 11. Calculation
9.1 Sample the material in accordance with Practice D3437. 11.1 Calculate the bromine index, B (mg-Br/100 g), as
follows:
10. Procedure
T × I × 79.9
B 5 (1)
10.1 Place 125 mL of electrolyte in a clean, dry titration
965W
cell, insert the electrodes, and begin stirring. Verify the volume
wh
...

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: D1492 − 13 D1492 − 21
Standard Test Method for
Bromine Index of Aromatic Hydrocarbons by Coulometric
Titration
This standard is issued under the fixed designation D1492; 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 the amount of bromine-reactive material in aromatic hydrocarbons. It is usually
applied to materials having bromine indexes below 500. Bromine Index in aromatic hydrocarbons, their derivatives, and related
chemicals.
NOTE 1—Other test methods for determining bromine-reactive material are Test Methods D1159, D1491, D2710, and D5776.
1.2 This test method has been found applicable to aromatic hydrocarbons containing no more than trace amounts of olefins and
that are substantially free from material lighter than isobutane and have a distillation end point under 288°C.is applicable to
samples with Bromine Index concentrations to 100 Bromine Index. The limit of detection (LOD) is for 1.5 Bromine Index and the
limit of quantitation (LOQ) is 4.9 Bromine Index.
NOTE 1—LOD and LOQ were calculated using data from the D16 PTP program. This estimate of LOD includes within-lab variability.
1.3 The following applies to all specified limits in this test method: For for the purposes of determining conformance with this
test method, an observed value or a calculated value the conformance of the test results using this test method to applicable
specifications, results shall be rounded off “to the nearest unit” in the last right-hand digit used in expressing the specification limit,
in 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 and health practices and determine the applicability of regulatory
limitations prior to use. For a specific hazard statement see Section 8.
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.
This test method is under the jurisdiction of ASTM Committee D16 on Aromatic Hydrocarbons Aromatic, Industrial, Specialty and Related Chemicals and is the direct
responsibility of Subcommittee D16.04 on Instrumental Analysis.
Current edition approved July 15, 2013Nov. 1, 2021. Published September 2013January 2022. Originally approved in 1957. Last previous edition approved in 20082013
ε1
as D1492 – 08D1492 – 13. . DOI: 10.1520/D1492-13.10.1520/D1492-21.
*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
D1492 − 21
2. Referenced Documents
2.1 ASTM Standards:
D891 Test Methods for Specific Gravity, Apparent, of Liquid Industrial Chemicals
D1159 Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
D1193 Specification for Reagent Water
D1491 Test Method for Test for Bromine Index of Aromatic Hydrocarbons by Potentiometric Titration (Withdrawn 1985)
D2710 Test Method for Bromine Index of Petroleum Hydrocarbons by Electrometric Titration
D3437 Practice for Sampling and Handling Liquid Cyclic Products
D3505 Test Method for Density or Relative Density of Pure Liquid Chemicals
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
D5776 Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
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
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 Other Document:
OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.1200
3. Terminology
3.1 Definitions:
FIG. 1 Automatic Amperometric-Coulometric Titrator Circuit
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.
Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
www.access.gpo.gov.
D1492 − 21
3.1.1 bromine index (B), n—the number of milligrams (mg) of bromine consumed by 100 g of sample under given conditions
(mg-Br/100 g).
4. Summary of Test Method
4.1 The specimen is added to a solvent and titrated with electrolytically generated bromine at room temperature. The end point
is determined by a dead-stop method. The time of titration is proportional to the bromine added to the specimen.
5. Significance and Use
5.1 This test method is useful for setting specification, for use as an internal quality control tool, and for use in development or
research work on industrial aromatic hydrocarbons and related materials. This test method gives a broad indication of olefinic
content. It will not differentiate between the types of aliphatic unsaturation.
6. Apparatus
6.1 Amperometric-Coulometric Apparatus, automatic, suitable for bromine index titrations with variable generator current and
timer. A typical circuit diagram of suitable equipment is shown in Fig. 1.
6.2 Syringe, 2 mL with needle and rubber cap seal.
6.3 Stirrer, magnetic.
7. Reagents
7.1 Purity of Reagent—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.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to
Type IV I or Type II of Specification D1193.
7.3 Electrolyte:
7.3.1 Preparation Cell Electrolyte—To make 1 L, mix 600 mL 600 mL of glacial acetic acid, 260 mL of absolute methanol, and
140 mL of KBr solution (119g/L).
7.4 Potassium Bromide Solution (119 g/L)—Dissolve 119 g of potassium bromide (KBr) in water and dilute to 1 L.
8. Hazards
8.1 Consult current OSHA regulations, supplier’s Material Safety Data Sheets, and local regulations for all materials used in this
test method.
9. Sampling
9.1 Sample the material in accordance with Practice D3437.
10. Procedure
10.1 Place 125 mL of electrolyte in a clean, dry titration cell, insert the electrodes, and begin stirring. Verify the volume of
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,BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC),
Rockville, MD.
...