This test method covers the determination of total bromine number in various double-bonded aliphatic compounds, using pyridine sulfate dibromide (PSDB), also known as Rosenmund-Kuhnhenn reagent.

This test method is being withdrawn with no replacement because the method uses a mercuric chloride catalyst for the reaction and carbon tetrachloride as a solvent. Test Method 234 closely resembles the iodine number required for biodiesel with the exception of the reaction. The test method as it is written works, but do we want to propagate this test method or replace it with a method that eliminates the mercury waste? Many companies would like to reduce the mercury usage as well as chlorinated solvents in their waste. There are two valid methods wich eliminate the mercury catalyst, D 1159 and D 2710. These methods still require a chlorinated solvent for aliphatic hydrocarbons but do not use mercury.

Formerly under the jurisdiction of Committee E15 on Industrial and Specialty Chemicals and Subcommittee E15.01 on General Standards, this test method was withdrawn in December 2008.

This test method is a good general means for measuring ethylenic (double-bond) unsaturation and is applicable to many compounds because of its speed, convenience, and minimum tendency for substitution. This test method has been applied to alpha-olefins, cyclic unsaturated hydrocarbons such as the cyclopentenes, unsaturated aliphatic side chains on aromatic rings, unsaturated esters and alcohols, acrylic and methyacrylic esters, acids, and salts, and other similar compounds. Diisobutylene and some tertiary-substituted hydrocarbons substitute to some extent but probably less by this test method than by most others. It is not satisfactory for such materials as commercial propylene trimer and tetramer, butene dimer, and mixed nonenes, octenes, and heptenes. For the bromine number of petroleum distillates that are substantially free of material lighter than isobutane and that have 90 % distillation points under 620°F (327°C) (such as gasoline), Test Method D 1159, is recommended.

1.1 This test method covers the determination of total bromine number in various double-bonded aliphatic compounds, using pyridine sulfate dibromide (PSDB), also known as Rosenmund-Kuhnhenn reagent. The total unsaturation is determined, whether conjugated or not.

1.2 This standard does not purport to address all of the safety problems 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. Specific precautionary statements are given in Section 7 and in paragraphs 5.1.1, 6.4.1, 6.7.1, and 8.1.