Application of multivariate statistical analysis to evaluate local sources of chlorobenzene congeners in soil samples

The distribution of tri- thru hexachlorobenzene congeners in the surface soil from five locations in the Niagara Falls/Erie County area of western New York State has been determined. The extract obtained by steam distillation was used directly with minimal additional clean-up steps for GC/MS analysis. Using GC/MS in the selected ion monitoring mode, a detection level of 100 pg/g (100 pptr) of the chlorobenzene congeners was achieved. Application of SIMCA pattern recognition and multiple discriminant analysis showed that the pattern of chlorobenzene congeners in soil samples collected near Love Canal is similar to the patterns found in other areas of Niagara Falls. The sources of these congeners may be nearby industrial plants and combustion sources. The soil samples from the town of Cheektowaga (comparison area) in nearby Erie County exhibit a different pattern of chlorobenzene congeners from the other soil samples.