A BIOASSAY-DIRECTED INVESTIGATION OF SYDNEY HARBOR SEDIMENT

A coal tar-contaminated sediment sample from Sydney Harbour, Nova Scot ia, Canada was examined for genotoxicity using a bioassay-directed fra ctionation approach. An organic solvent soluble fraction, prepared fro m the marine sediment by ultrasonic extraction, was fractionated into compound classes using a sequential alumina and Sephadex LH20 clean-up procedure followed by high performance chromatographic techniques. Th e PAH-containing fractions were analyzed using gas chromatography-mass spectrometry (GC-MS) and reversed phase-high performance liquid chrom atography (RP-HPLC). The composition of the fractionated material was also characterized using Salmonella typhimurium microbiological assays to identify fractions with mutagenic potency. The fraction containing the PAH was the major source of mutagenicity requiring microsomal act ivation. Compounds responsible for some of the mutagenic activity in t he PAH-containing fraction, including benzo[a]pyrene, benzo[ghi]peryle ne and indeno[1,2,3-cd]pyrene, were identified through a combination o f RP-HPLC followed by GC-MS of individual subfractions.