Distribution of Chlorinated Hydrocarbon Pesticides and PCBs in the ...

sampling site and used from a cleaned cooler. At the sampling
site on the edge of the island, a cleaned pre-labelled 4 L sample
bottle was installed in the sampler which was lowered rapidly to
10 metres, held open for approximately one minute, closed and
recovered. Bottle caps lined with cleaned FEP teflon sheet were
installed and the bottle stored in an insulated box for
transportation back to the lab. Three replicate samples,
nominally 8 L each, were collected for chlorinated hydrocarbon
analysis. Each sample consisted of two 4 L bottles. Three
additional samples were collected for filtration for particulate
organic carbon analysis on the second trip.
2.2.2 Filtration and Extraction
Sample bottles were shaken to resuspend settled particulate
and gravity filtered through a glass fibre filter (142 mm Gelman
AE) in a solvent rinsed (acetone then dichloromethane) 4L
separatory funnel. The filter was removed with cleaned forceps,
folded to retain particulates and stored frozen in a cleaned
aluminum foil pouch. The filtrate was serially extracted with
glass distilled hexane (10 mL then 2 x 100 mL) and the extracts
combined in a 500 mL stoppered flask. This was repeated for the
remaining sample bottle and the combined extracts dried by
standing over anhydrous sodium sulphate for 10 minutes. The
extract was taken down by vacuum rotary evaporation at 20°C to 3
mL and quantitatively transferred by pipette to a 10 mL ampoule
with 3 x 1 mL hexane sample flask rinses. After cooling and
solvent vapour removal, the ampoule was sealed off for shipment
and analysis. Procedural blanks were carried through the
extraction using pre-extracted sea water as a sample.
2.3 Chlorinated Hydrocarbons in Sea-Ice (May 1986, June 1987)
A core of first year sea ice was melted out using the hot
water ice drill with a 60 cm diameter melting ring. The ice
cores, approximately 1.4 m in length, were lifted out, placed