Application of Capillary Chromatography to the Study of the Cycling of PCBs on Suspended Particles

摘要

Sediment trap samples taken from southern Lake Michigan during 1978 were analyzed for polychlorinated biphenyls. It was found that PCB concentrations were minimally correlated with the percent organic carbon content of settling particles. The relative composition of the Aroclor compounds suggests that the atmosphere is the major source of this material. This is in agreement with the data of other investigators in the Great Lakes region. Capillary GC techniques have been developed which satisfactorily separate most of the isomers in Aroclors 1242 and 1254. These techniques have been used to evaluate the concentrations of PCBs associated with settling particles in Lake Michigan. This analysis shows there to be a decrease in the concentrations of Aroclors with depth. Moreover, there also exists a decrease in the levels of the trichlorinated biphenyls of the Aroclor mixture as one approaches the lake bottom. It is believed that microbial degradation may be partially responsible for this observation. There is presently a study to isolate bacterial species from Lake Michigan sediment in an effort to shed further light on this experiment.