Determination of bromine index of petroleum hydrocarbons according to ASTM D2710 and IP 299

The bromine index is an important parameter for the determination of aliphatic C=C double bonds in petroleum hydrocarbons. For the titration a solvent mixture of glacial acetic acid, methanol and dichloromethane is used. In this application note the chlorinated solvent was replaced with toluene. The bromine is generated in-situ from a bromide/bromate solution and usually determined using electrochemical titration at 5 °C. Using the double Pt-wire electrode for indication, the bromine index is determined by titration with bromide/bromate solution as titrant.