EVALUATION OF PACK MELTING EFFECT ON POLYCHLOROBIPHENYL CONTENT IN SEA-WATER SAMPLES FROM TERRA-NOVA BAY ROSS SEA (ANTARCTICA)

The total contents of PCB in sea water samples collected in Terra Nova Bay during the Italian expedition 1988-1989 are reported along with individual PCB isomer concentrations. Liquid-liquid extraction with n-hexane was found to be more reproducible than solid liquid extraction. Clean-up of extracts was effected on a Florisil column which in our experimental conditions eliminates interferences due to other chlorinated pesticides. PCB determination and identification were performed by high resolution gascromathography (HRGC) and HRGC/FT-IR spectrometry respectively. The results obtained showed for the Antarctic area under study a typical value of 0.6 ng/l as total PCB concentration and a temporary local increase up to 1.7 ng/l which may be due to pack melting. Distribution among congener classes showed a chlorination level similar to that observed for oceanic waters and centering on three to penta substituted isomers