Polychlorinated terphenyls (PCT) in some British birds.

Abstract

The samples which contained the highest amounts of PCT also contained the higher amounts of PCB, but the amounts of the latter were 1 to 2 orders of magnitude greater, possibly reflecting the relative usage of the polychlorinated materials. The relative amounts of the perchlorinated ortho-, meta- and para-isomers of terphenyl are of interest. Three peaks were detected on GLC; the identities of these, in order of increasing retention times, were assigned by DOGUCHI et al (1974) to the ortho-, para- and meta-isomers respectively. Their identity was confirmed during the present work by perchlorination of the respective terphenyl isomers. The ratios of the areas of the perchlorinated isomers in the standard preparation of PCT were ortho:para, 0.8 to 1 and meta:para, 1.4 to 1. With the exception of only one sample — a Barn Owl liver — the ratios for the sample extracts were all lower than those for the standard. DOGUCHI et al (1974) showed a similar result in their chromatogram of a Japanese human fat extract. This may be an indication that the ortho- and meta-isomers may be degraded more rapidly in the environment than the para-isomer; experiments showed that there was no change in the ratio of the isomers when the standard material was put through the complete method. It is hoped that further work with a wider variety of bird species may help to clarify the situation.