Polychlorinated Biphenyl DDT And Dieldrin Residues In Grey Seal (Halichoerus-Grypus) Males Females And Mother-Foetus Pairs Sampled At The Farne Islands England During The Breeding-Season

PCB, DDT, DDE, dieldrin and total non-polar organohalogen residues have been determined in the blubber-lipid of grey seals (Halichoerus grypus) sampled during the 1972 breeding season (November) at the Farne Islands off the north eastern coast of England. PCBs were analysed by gas-liquid chromatography linked to a chlorine- and carbon-selective microwave plasma detector and total organohalogen residues were determined by microcoulometry. Total organohalogen residues were negatively correlated with blubber thickness and positively correlated with age in males (aged 1 to 24 y) and females (aged 5 to 38 y). However, the correlation of blubber-lipid residue with age in males depended upon the inclusion of immature (aged < 6 y) animals, and in females reflected only a small residue increment. The mean blubber organohalogen concentration of the males was significantly greater than that of the females. PCB and DDT group residue concentrations were significantly correlated. PCB, DDT, DDE and dieldrin were detected in the liver of mother/foetus pairs demonstrating transplacental movement of these residues. The possibility of the condition of the seals at breeding time influencing residue levels and of these residues influencing the health of the population is discussed.

Microcoulometric Determination Of Total Organo-Chlorinepesticide And Polychlorinated Biphenyl Residues In Grey Seal (Halichoerus-Grypus) Blubber

A procedure for estimating total organochlorine pesticide and PCB residue in seal blubber at concentrations of greater than 1μg g-1 of lipid is described. Lipid is cleaned up by alumina column chromatography, and the halogen concentration of the resulting hexane eluace is determined by combustion and microcoulometry. Results are similar to those obtained by gas chromatographic analysis and can be used to interpolate between results so obtained when data on specific organochlorine compounds is not required for each sample. The organochlorine residues recovered in this manner did not constitute all the halogen determined by combustion and microcoulometry of seal lipid. Analysis by the total halogen procedure was 2.5 tunes faster than the rate achieved with a combination of liquid and gas chromatography operated manually; the requirements for laboratory equipment and space for sample preparation are reduced.