Determination of coplanar polychlorobiphenyl congeners in biota samples

Abstract

A method for the separation of coplanar congeners of polychlorobiphenyls (PCBs) (IUPAC Nos. 81, 77, 126 and 169) from other organic micropollutants such as hydrocarbons, organochlorinated pesticides and other PCBs is described. It involves a two-step clean-up procedure with sulphuric acid treatment and LC fractionation (Hypercarb column) and permits the isolation of the coplanar congeners of PCBs in biota samples. The separation of the coplanar PCBs in the Hypercarb column requires only 100 ml of n-hexane. Recoveries ranged from 84 to 97% for these and sixteen other PCB congeners. Gas chromatography (GC) with electron-capture detection of all the compounds was performed using capillary GC columns of different polarity, CP-Sil-8 CB or DB-5, DB-17 or DB-225, followed by confirmation by GC—mass spectrometry in the electron impact and selected ion monitoring mode. The whole analytical method permits the determination of individual PCBs in biota samples at a level of 1 ng/g wet tissue.