Gas chromatographic determination of residues of bromopropylate and two of its degradation products in honey.

An analytical procedure is described for determination of residues of bromopropylate (BP) and its main degradation product 4,4'-dibromobenzophenone (BBP) in honey. The method also allows the determination of 4,4'-dibromobenzilic acid (BBA), a potential intermediate to BBP. The method involves dissolution of the honey in water and separation of BP and BBP from BBA on a partition column. BP and BBP are further cleaned up and separated on a silica gel column and determined by gas chromatography (GC) with electron capture (EC) detection. BBA is oxidized with potassium dichromate to BBP, which is partitioned into dichloromethane and further cleaned up on a silica gel column before determination by GC with EC detection. The method is sensitive to 0.02 mg BP or BBP/kg and 0.023 mg BBA/kg honey.