M11 PM Internal Exposure
Monday, 14 November 2005: 1:50 PM - 5:30 PM in 343-344

(MCL-1117-719098) Application of equilibrium sampling devices to measuring internal exposure in harbor porpoises and otters.

McLachlan, M.^{1, 2}, Ossiander, L.¹, Kömp, P.¹, ¹ Baltic Sea Research Institute, Rostock, Germany² ITM, Stockholm University, Stockholm, Sweden

ABSTRACT- Equilibrium sampling devices (ESDs) are a potential method for quantifying internal exposure of organisms to organic contaminants. Fibers coated with polydimethylsiloxane (PDMS) were evaluated as ESDs for polychlorinated biphenyls (PCBs) in tissue from harbor porpoises and otters. The fibers were inserted directly into the tissue and allowed to equilibrate. Thereafter, the fibers were cleaned by drawing them through a septum and wiping them with tissue. They were then submitted to thermal desorption in a GC injector and the PCBs were analyzed using GC/MSMS. The relative standard deviation of the PCB levels in different fibers exposed to the same tissue averaged 15 %. Equilibration was rapid (< 1 minute) and reversible. Analysis of 9 porpoise blubber samples with PCB concentrations ranging over 1.5 orders of magnitude yielded a linear relationship between levels in the fiber and concentrations determined in the blubber using conventional analysis. Measurements in different tissues from an otter indicated that PCB fugacities were similar in a range of organs but that they were considerably higher in adipose tissue. The results suggest that PDMS coated fibers may be a simple and useful tool for measuring internal exposure and understanding the distribution of organic contaminants in large organisms.

Key words: fugacity, equilibrium sampling devices, internal exposure