Document DMdO4D5MOxM6vGV55R90L1x6o

Bob Keller dictated these notes to outline our position as seen by Keller, Dietrich, Emery and Tucker after reviewing our analytical results and the published literature to date. This is our present "legal" position on PCB in wildlife. It can turn out that Risebrough will .be proven to be correct and hence wre are not ready for an open challenge in the press if it can be avoided. '- This .is for background information only, not for publication. ms Att. W. R. Richard DSW 388057 STLCOPCB4101250 ROUGH DRAFT R. E. Keller to Ur. Richard per phone hy Stanley - 2/28/69 Publications in hand (.1,2) show that Risebrough has not made a positive structure identification to presence of chlorinated hydrocarbons (Biphenyls) let alone Aroclor products in material he has worked with. His approach is not an absolute identification procedure. It's based on similar retention times for 10 com ponents eluted through a gas chromatography column. This measure ment is not specific for chemical compounds in unknown mixtures. Furthermore, the electron capture detector used to monitor sep arated component is not specific for chlorine or even halogens. Work in our labs shows at least 13 components in Aroclor 1242, 17 in Aroclor 1254 and l4 in Aroclor 1260 with different retention times than those reported by Risebrough. More information is needed about un-reported experimental chromatographic conditions used by Risebrough to resolve differences between labs. Risebrough. has based his conclusions implicating chlorinated biphenyls on work by Holmes (3), Holden (3a) Widmark (4), and Jensen (5). Holmes and Holt obtained similar gas chromatography containing 11,13 and 7 peaks respectively for commercial polychlo- 'biphenyl resin. Holmes and Holden also did not make a positive structure identification. Widmark and Jensen in Europe (Sweden) obtained a similar gas chromatography for eagle extracts. Chromatographic fractions from this work were identified structurally by Mass Spec as higher chlorinated biphenyls. Risebrough, in his reported work has apparently made no positive identification of this type. His implication of chlorinated biphenyls appears to be by reference back to above work through similar chromatograms. ^ To the best of our knowledge, no one has identified components structurally in biological systems'as-chlorinated biphenyls in U.S.A. Work is underway in our labs on an unequivocal structure identification of unknown organic species in national products using gas chro matography and mass spectroscopy techniques. . REFERENCES: (1) Risebrough , R. W., Chem. Fall,,Qut, First Rochester Conference on Toxicity, in the Fred's (US68) (2) Risebrough, R. W. Nature, Draft of Paper in Press DSW 388058 STLCOPCB4101251 2- HOUC-K DRAFT REFERENCES - Cont'd. (5) Holmes, D. C. & Simmons, J.H., Tatton, J., Nature 216, 227 (1967)- ------------ <* (5a) Holden, A.V. and Marsden, K., Nature 2l6, 1274 (1967) (4) Widmark, G., J, Assoc. Off., Anal. Chem. 50, 1069 (19^7) (5) Jensen, S., New Scientist, 32, 6l2 (1966) from R. S. Keller per phone to M. Stanley 2/28/69 STLCOPCB4101252