Document YL5GLY5KybJrzowmO85r3w7O

J-- ir it CORPORATE 1J GENERAL ELECTniC COMPANY, RESEARCH AND DEVELOPMENT CENTER, KO . BOX 8 SCHENECTADY, NEVV YORK 12301, Phona (51BJ 38S-2211 ! R ^ E A H C H Ari-D * , > ^ ^ L O r fvrc/U 7 Building K-l, Room 3B35 January 15, 1979 C h Dr. James D. McKinney NIEHS, Chemistry Section POB 12233 Research Triangle Park North Carolina, 27709 o >-* 8 5? Dear D r . McKinney: I'm sorry to be engaged in such a slow-moving dialog on the PCB/PCDF analysis issue, but your letter andjdatajpackage of Dec. 4 took two weeks to get here, and I couldn't get our mass spectrometrist to go over them with me until after the holiday season. H ow ever, now that we've been able to put together the various pieces from your Sept. 15, Nov. 15, and Dec. 4 communicajtions, I think we have a better feeling for the situation. In] addiction, I have boon able to get back to our transformer people for further info on the sample. Here's what's turned up: 1. Oricin of "used" transformer fluid. In my letter of Fe-bruary 15, 1978, I indicated that- the sample I'd sent! had come from ic single industrial transformer that had had 0 yeats of heavy dut y service, but could h:ive been refilled an unknown (number of times over the years. iVve now learned that this identification was incorr Cw i;: the particular sample that Dr. R.C. Osthoff [passed on to me, and which I passed on to you, was a' blend of 3-4 old [samples of used oi 1, prepared for Osthoff by Dr. W.A. Fessler, wi!th the intent of ena h Iing the detection of any PCDF's that might have [been present xn any cf them. Dr. Fessler also tells me that the phenyl tin stabilizer was used up until 1963, not 1953, so that the -observed composition (Aroclor 1260, trichlorobenzene, * -trachlorobenzene, phenyl tin) can be dated pretty well to the 1953-'* i period. 2. Identification of Ci2H 2^^6 Species. I think we're all agreed now . m a r m e r e xs proDaniy some speexes in new transformnr flu-id fraction New T.F.-4B having the empirical formula 2 C ^G^ but that neither its chromatographic behavior (not adsorbed on silica, strongly adsorbed on alumina) nor its fragmentation pattern are those expected of a heSiachlorodibenzofuran. You indicated at the end of your Nov. 15 letter that you did not] feel that further chv:nv- .cal characterization was justified. In this case, would you be wi lli'ng to send us some part of your fraction New t [.F.-4B? Since we go; 783216 i *` VJEHA Dr. James D. McKinney -2- January 15, 1979 c started on this problem, we too have acquired a high resolution mass spectrometer, and our mass spectrometrist, Dr. W.V. Ligon, has become personally curious about the question and would like to take a crack at it if you would be willing to share your sample. 3. Model Candidates for Forming ? C D F 's . In your Dec. 4 letter, you indicated surprise at not having found PCDF's, in view of their reported formation under "model" conditions. The only thermal oxi dation experiments that I'm aware of are those of Rappe, which in volved heating to 550-850C. These would not seem to meaningfully model processes that might occur in a transformer operating at 20-95C, so perhaps I missed something. Would it be possible to send me a reference to the "model" conditions you alluded to? 4. Identifications of "Hydrocarbons". In Don Harvan's memo to you of August 4, he identified a number of minor components as hydrocarbons, phthalates, thiazoles, bromine compounds, etc. including one prominent single species denoted a C 1 6 H 34 hydrocarbon. As regards the latter, we note again that this material appears in fractions (those strongly adsorbed on silica) which are "wrong" for a saturated aliphatic hydrocarbon; moreover, I knew of no likely source of m o l e c u lar ly pure C 1 6 H 34 species. Reasonable alternatives having the same molecular weight would include diallyl adipate, vinyl dodecanoate, and j:-buty I-pheny1-phenol. Do I conclude correctly that all of your "hydrocarbon", phthalate, bromo compound, etc. identifications arc based upon low resolution molecular weight alone, and hence arc purely suggestive rather than definite? 5. Identification of Ci2Hio-xClx3 Species. - In all your letters you have referred to these species, which ware quite prominent in the old transformer fluid, as polychlorinated diphenylethers (PCDPE) . I note from Donald Harvan's memo of 9/18/78, however, that these species were soluble in base, and were identified as polychlorinated diphenylethers rather than the isomeric polychlorinated biphenols solely on the basis of failure to silylate. V7hat immediately comes to mind is that (a) failure to undergo silylation would not be un expected for a heavily substituted phenol; (b) solubility in aqueous base is really pretty conclusive evidence for having a phenol rather than an ether; (c) a slow hydrolysis of highly chlorinated biphenyls to polychlorinated biphenols at 20-95 in a system containing H 2O and 783217 Dr. James D. McKinney -3- January 15, 1979 various metal oxides would, certainly not be implausible; a parallel, though predictably slower, conversion of the polychlorinated benzenes could also have been going on but without ever bringing the p o l y chlorinated phenol level within 1-2 orders of magnitude of P.W. Albro 1% detection limit. In short, the data that you sent me really argue pretty strongly that the species y o u 'r e "looking at are biphenols rather than diphenyl ethers. I recognize that there may be other pertinent data which somehow failed to get bundled up for the mailing to Schenectady. If so, I'd appreciate hearing about it. Thanks again for your assistance. Sincerely yours, John F. Brown, Jr. Mgr - Life Sciences Branch PHYSICAL CHEMISTRY LABORATORY O tTl O O o 783218