Bromine number

Determination of the bromine number of a triglyceride : Above, triglyceride in an oil with a blue- marked saturated fatty acid residue, a green- marked monounsaturated fatty acid residue and a red- marked triple unsaturated fatty acid residue. Arrows point to the four carbon-carbon double bonds. The triple acylated glycerine ( marked in black ) can be seen in the center of the structural formula above . Below the bromination product after the addition of four bromine molecules (Br ₂ ), corresponding to eight bromine atoms.

The bromine number (BZ) is a measure of the olefin content ( alkenes ) of a substance.

definition

This figure is based on the simple addition of bromine (Br ₂ ) to the double bond of alkenes.

For every mole of carbon-carbon double bond, one mole of bromine is consumed. The unit is therefore usually g bromine per 100 g sample.

application

It is important to determine the bromine number and thus the content of carbon-carbon double bonds in refineries and petrochemical plants in order to determine parameters for further processing.

The proportion of carbon-carbon double bonds (contained in the acyl radicals of unsaturated fatty acids) can be determined in triglycerides (fats and fatty oils) .

It is important to adhere to the method so that the addition also corresponds to the stoichiometric amount.

Automatic devices are used for quality controls in food laboratories or series determinations in the petrochemical industry. The determination is carried out coulometrically in them .

Typical bromine numbers

• Hexene (C ₆ H ₁₂ ) has a bromine number of 189.

See also

• Iodine number