RETENTION CHARACTERISTICS OF SOME SELECTED HALOGENATED ENVIRONMENTAL-POLLUTANTS IN SILICA AND BONDED NORMAL-PHASE LIQUID-CHROMATOGRAPHY

Seven bonded stationary phases and unmodified silica were investigated regarding their retention properties towards a number of halogenated environmental pollutants including 26 individual polychlorinated biphenyl congeners. No simple retention-structure relationship was found for the polychlorinated biphenyls but a number of phases demonstrated similar selectivities towards the investigated congeners. The retention of compounds with aliphatic carbons were substantially influenced by the presence of hydrogens possessing acidic properties due to inductive effects of adjacent chlorine or oxygen atoms. Solute molecule ether oxygens were shown to promote retention by hydrogen bonding only on silica and phenylpropyl silica. Polybrominated diphenyl ethers demonstrated a complex retention behaviour on the different stationary phases. Indication was found that bromine may be directly involved in the retention mechanism.