Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D1159-23 – Standard Test Method Technical Guide
🧪 Scope and Applicability
This test method, designated as ASTM D1159-23 (and technically equivalent to Energy Institute Standard 130/20), establishes a standard procedure for determining the bromine number of specific petroleum distillates and commercial aliphatic olefins using electrometric titration. The bromine number indicates the quantity of bromine-reactive constituents, predominantly olefins, under the specified test conditions.
It applies to petroleum distillates substantially free of material lighter than isobutane, with a 90% distillation point under 327 °C (626 °F). For commercial aliphatic mono-olefins, the method is applicable within the bromine number range of 95 to 165.
| 🟦 Material Type | 📏 Specification | 🎯 Bromine Number Limits |
|---|---|---|
| Petroleum Distillate (90% point < 205 °C / 400 °F) | Gasoline, kerosine, light distillates | Maximum 175 |
| Petroleum Distillate (90% point 205–327 °C / 400–626 °F) | Gas oil range distillates | Maximum 10 |
| Commercial Aliphatic Mono-Olefins | Propylene trimer/tetramer, butene dimer, mixed nonenes | 95 to 165 |
| Normal Alpha-Olefins | All types | Not satisfactory for this method |
The values stated in SI units are regarded as the standard. The values given in parentheses are for information only.
⚙️ Procedure and Safety Precautions
The determination relies on an electrometric titration to precisely identify the endpoint of the bromination reaction. The method requires strict environmental controls and reagent purity, with reagent water conforming to ASTM D1193 Specification for Reagent Water typically specified. The extensive applicability across gasoline, kerosine, and commercial olefins requires analysts to closely follow the standardized parameters.
⚠️ Critical Safety Notice
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. Specific warning statements are provided in Sections 7, 8, and 9 of the standard and must be reviewed prior to handling reagents or conducting the test.
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. Specific warning statements are provided in Sections 7, 8, and 9 of the standard and must be reviewed prior to handling reagents or conducting the test.
📊 Key Measured Properties and Analytical Guidance
The magnitude of the bromine number is an indication of the quantity of bromine-reactive constituents, not an identification of the constituents themselves. Therefore, its application as a direct measure of olefinic unsaturation should not be undertaken without the detailed study given in Annex A1 of the standard.
⚡ Critical Limitations for Analysts
Olefinic Unsaturation: Beware of interpreting the bromine number as a direct measure of olefinic unsaturation without consulting Annex A1.
Low Bromine Numbers: For petroleum hydrocarbon mixtures with a bromine number less than 1.0, a more precise measure can be obtained using Test Method D2710. If the bromine number is less than 0.5, Test Methods D1492 or D5776 (Bromine Index methods) must be used. The common practice of multiplying the bromine number by 1000 to estimate the bromine index is strictly not applicable for these lower values.
Standardized Development: This test method was developed in conformance with the World Trade Organization (WTO) principles on international standardization, ensuring its suitability for global trade and regulatory frameworks.
Olefinic Unsaturation: Beware of interpreting the bromine number as a direct measure of olefinic unsaturation without consulting Annex A1.
Low Bromine Numbers: For petroleum hydrocarbon mixtures with a bromine number less than 1.0, a more precise measure can be obtained using Test Method D2710. If the bromine number is less than 0.5, Test Methods D1492 or D5776 (Bromine Index methods) must be used. The common practice of multiplying the bromine number by 1000 to estimate the bromine index is strictly not applicable for these lower values.
Standardized Development: This test method was developed in conformance with the World Trade Organization (WTO) principles on international standardization, ensuring its suitability for global trade and regulatory frameworks.
❓ Frequently Asked Questions
🔍 What does the bromine number represent? The bromine number represents the grams of bromine consumed by 100 g of sample under the specific conditions of this test method. It provides a measure of the quantity of bromine-reactive constituents in the sample.
💡 What specific materials fall within the scope of ASTM D1159-23? The scope includes petroleum distillates (substantially free of material lighter than isobutane, with a 90% distillation point under 327 °C) and commercial aliphatic mono-olefins (e.g., propylene trimer, butene dimer) falling within the bromine number ranges for which precision has been established.
⚡ Can this method be applied to normal alpha-olefins or very dilute samples? The standard explicitly states that this test method is not satisfactory for normal alpha-olefins. For samples exhibiting very low bromine numbers (< 0.5), the coulometric titration methods (D1492 or D5776) are specifically required.
📌 How are the results standardized for international use? This standard was developed in accordance with the World Trade Organization Technical Barriers to Trade (TBT) Committee’s principles for international standardization, ensuring global consistency and acceptance of the test results.