Lake trout homogenates J and K (ca. 1995) were
supplied by Department of Fisheries and Oceans, Burlington,
Ont. The fish contaminant regimes differ in that
J fish are high in PCB and K fish are high in toxaphene.
Ten grams of each trout homogenate was thawed and
spiked with organophosphate compounds. The sample
was immediately mixed with 6 g of pre-cleaned sodium
sulphate and allowed to equilibrate for 2 h. Samples
were extracted with three 100 ml portions of hexane:
acetone (80:20) using 1-min polytron extraction intervals.
After settling, the extraction solvent was filtered
through an Allihn funnel sequentially filled with 45 g of
fired sodium sulphate and 20 g of petroleum ether washed
Celite. The Celite filter aid had also been prewashed
with dichloromethane prior to use. Extracts
were combined with 5 ml isooctane in a 500 ml round
bottom flask and concentrated 1 ml using the method
described for water.