Document mpkYrNQpn5yZkg5pJpxKVMzYk

DEPARTMENT OF HEALTH. EDUCATION. AND WELFARE PUBLIC H E A LTH SERVICE N A TIO N A L IN S TITU TE S OF H EALTH January 23, 1979 Or. John F. Brown Manager, Life Science Branch Physical Chemistry Laboratory Building K1 , Room 3B35 General Electric Company Research 6 Development Center Post Office Box 8 Schenectady, New York 12301 R E C E IV E DEN !KCf<! S?N:TiLs: JAN2 91979 J. F. BROWN K Dear Dr. Brown: It is obvious to me at this point that we are not communicating. Perhaps I have assumed a greater appreciation and understanding of the problems and difficulties involved than you and your staff may have at this time. However, I will briefly address the questions raised in your letter of January 15, 1979, and then suggest some alternatives to communicating this matter. 1. Furan Nominal Mass Equivalents. We now know that there is a series? of these "furan like" (mass spectrometrica11y similar but chromatographs cally different) compounds in the used transformer fluid also. They are found in the fraction most enriched in chlorinated diphenyl ethers off acidic alumina. More fluid (new and used) will have to be processed in order to obtain sufficient quantities of these fractions for further study; We plan to obtain exact mass measurements pending availability of proper fractions and instrument time. 2. Model Conditions for Furan Formation. 1 have enclosed a preprint of an article describing some additional work in this area. These workers claim that the furans can be formed at temperatures as low as 270 for one week. I will not attempt to extrapolate that to the transformer situation. My surprise was in not having been able to find detectable levels of furans. Appreciable levels would not be expeated in view of the possible competing reaction leading to diphenyl ethers. Without starting over, all we can say at the moment is th^t if the furans are present they-are <100 ppm. 3. Identification of Hydrocarbons. It was not our intent to elaborate the identification of minor components at this time. However, our identi fications are generally based on two or more of the following criteria: proper chromatographic behavior, proper molecular ion including isotopic ratios, and expected fragmentation. Although the identifications are not generally considered definite, they are not based on molecular ions alone. In the case of Cj^H ^ hydrocarbon which is a major component among the 783114 o % o o o '* . Page 2 minor ones, we have an exact mass measurement as] confi rmng evidence. In addition, it is not surprising for a compound such as this in such a com plex mixture to overlap with several fractions, j The 1atter speaks for our experience in this area. I A. Identification of Chlorinated Pi phenyl ethers. There is no question about this one. All of the following is consistent wijth this identifica tion: chromatographic behavior under diverse conditions, mass spectral patterns including parent ions, diagnostic fragments such as M-C0C1 , and isotopic ratios, perchlornation to decachlorodiphenylether, and UVabsorbance. We also have representative standards. In fact, we now know that the chlorinated diphenyl ethers constitute approximately 8 mol. per cent or 11 wt. percent of the used transformer fluid. | Chlorinated biphenylols .wi 11 silylate, you just have to use the rigljit silylating condi tions. Also, the diphenyl ethers have some water solubility, hence their presence in the aqueous basic solution is expected since there is very little of anything else to compete for water solubility. 5. Origin of "Used11 Transformer Fluid. I find! it very disturbing that* the identification of this fluid as originally stated]was incorrect. T{iis is the one area for which we had hoped we could] rely on you, as a defini tive history of the sample is critical to any publication of this work." We agreed and continued to work with this fluid because it offered a peculiar challenge to a separations group. Our purpose and approach to this study was purely scientific; however, we dIfd hope to publish our findings as we should. In fact, we now feel we1have ^a general scheme for any future analysis of such fluids which utilizes a combination of UV- monitoring, chromatography and perch lorination techniques to avoid arbi trary "cuts" and solvent changes, etc. ! In short, we have researched the methodology whi 1e trjying to provjde you some answers. Obviously, there is some risk involved in doing this, but the urgency and need were there, and we have the expertise. I will not continue to send raw data and our interpretation as I have done in the past, for it only seems to get taken out of context, This is real 1y not practical anyway as we have reams of data on ttie subject now. Rather, I would suggest that you visit with us so that w can ay out our data and talk about it some in detail. 1 On the other hand., if you w i 11 prov ide a sample of used transformer fluid of known origin and usage, which would not seem to be a formidable task for GE, we will app y our methods and publish.our data for the scientific community to evaluate. Of course, another alternative is for you to do the work yourself; however, if you choose to do this, I think it will require a great deal more appreciation of the problems and difficulties involved and familiarization with metho- GENP 010304 783115 dologies than apparently you have at the moment (as least as conveyed your letters on the subject). S incerely, ;y 'L James 0. McKinney, Ph.Dr-- Chief, Environmental Chemistry Branch Enclosures 1 703116 I POLYCHLORINATED- DIBENZOFURANCPCDFj'_FORKATIQIt .FROM *. PCS MIXTURE BY HEAT AND OXYGEN --- - I'I '. ,' . . J _* -y : ... V -z By f.forita, J.Kakagawa and C. Raope (* TSkyo Metropolitan Research Laboratory ~ of Public-rTealth, 3-24-1, Hyakunin-cho, Shinjuku-ku, Tokyo , 160 Japan University of Uraea) S-9?l 87 Urr.ea 6, Sweden) 1 M G ~r. ci- GENP 010306 783117 fc ) Polychlorinated _dibenzofurans(P(jDFs)_.are known ^highly 'toxic. compounds (.HOFMANN ,`1956! -Like their close ^ hloro^benzodio^ii\|naloJgues, certain, of the PCDF ,'-V . coiapounds'are*7eartrem^Xjc..toxicx O q aarulals% causing ' *; "chloracne and producing extensive, irreversible l i v e r -.* damage (KIMBROUGH 1972, TAYLOR 197*01 PCDFs are also extremely toxic to chicks (MCKINNEY jet al. 1976), Recently PCDFs are considered to have played a signifir- cant role in the causation of "Yusho" to which PCB mixture(Kanechlor 400)have been found responsible (NAGAYAHA. et al. 1976). * The PCDF derivatives have been detected and i identified in manufactured polychlorophenols (NILSSON and REN3ZRG 197*0 BUSER *1975) and in PCB preparations of various source (VOS et al. 1970? ROACH and POMERANTZ 1974; BOWES et al. 1975, 1976; MORITA et al. 1977). From the structural similarity, the posibility of PCDF formatin from a PC3 source was an item of special interest. The photochemical transformation has been studied in several reports (SAFE and HUTZINGER 1971; HUTZINGER et al. 1972; ANDERSON et al. 1975). There is also some evidence that PCDFs may be produced thermo- chenxically. PCB mixture used at high temperature as a heat transfer agent were shown to have an increased amount of PCDFs (KORITA et al. 1977). In Yusho oil an unusually high level of PCDFs was considered as a result of a long term heating of PCBs for heat transfer use. These indication led us to heating experiments to learn Any correspondence be addressed to M. Mori ta,Ph~.D." -*Tj 783118 GENP 010307 ilw G b o i-'J ^ ^ u u _ L b j- u u c ) j s-- W ^ r M C V ^M W4 VM W reaction. We here present a preliminary result of our heating experiments of an American PCB mixture (Arochlor 1248). EXPERIMENTAL ! . PCB mixture (Arochlor 1248, lg) was sealed with air, * oxygen or nitrogen ixf pyrex glass tube(8mm X. 2 0 C m ) .and heated in an byeni_ After cooled jto room temperature/"" ~ ~2\Jithk.,,pontent__was^di ssolyed with 10 ml.bf `n-hexane andvigorously 'shaken'Vwxth pelletsT o f "sodn.ua hydroxide. * * Half of the solution was subjected to-PCDF-.analysis. Clean up procedure was similar to tha described b y MTYATA et al.. Aluminium oxide (Merck Aluminium Oxid 90; aktiv, 27g) was packed in a glass column (10mm X 300mm) with hexane (Mallinkrot nanograde). PCBs were eluted with 200ml of dichloromethane+hexahe mixture (5-95) and then with 50ml of 20$ dichloromethane mixture. PCDSSs- were recovered with 250 ml of I1 dicl hlor| omethane+hexane-r (20:80) mixture. The PCD? fraction was concentrated to `I I the volume of 1 ml with a Kuderna-Danlsh concentrator* 1 and then nitrogen gas flashing. An aliquot of the solu tion was injected to gaschromatographly-mass spectrometer (Shimadzu LK39000) for quantitative a|nd qualitative analuses. The amount of PCDPs were determined by comparing the peak areas of parent mass chromatogram with those of authentic PCD? mixtures assuming that the 1sensitivity of total ion collector is the same among PCD? isomers regardless to the difference of chlorine position and number. GC conditions was as follows, Column 07-210 (2$) on Chromosorb WAW DCMS (100/120) Carrier gas He 30 ml/min. RESULTS AND DISCUSSION Three parameters, heating temperature, oxygen GENP 010308 783119 i partial pressure and tine, were studied for the forma tion of PCDFs. As shown in Fig.l and 2* the conditions were critical. The maximum yield in this experiments was about 0.2 Heating PCBs for 1 week showed that PCDFs were formed over about 270 G -and reached* to the maximum; level at-about 500* C. (in oxygen). The lower level, at 330 C "" - - *teipep a,, : ;emperature~ seems necessary for the PCDF_formation. Ko significant increase of PCDFs was observed in the heating at 2 7 0 C and higher yield was obtained at 330 C rather than at 300c. A: very slight increase of PCDFs was noticed in the heated PCBs at 330 C under niltrogen. Pig. 2 shows the effect of time vlhen PCBs were heated at 300*C. Under oxygen, the maximum was found after 1 week while it was found after 2 weeks in air*. Prolonged heating decreased the F|CDFs level indicating that once formed the PCDFs were decomposed under these conditions. Very slight increaseI of t1he PCDF level was .observed In long term experiments heating PCBs under nitrogen. From these observations, the reaction may be delineated by the following description. (1) Oxygen atom in PCDF skelton comes from oxygen gaseous in the sealed tube. (2) Temperature over 270C is necessary for the transformation but at temperature over 330C PCDFs decomposes. (3) PCDFs level seems to be deperrained by the transient..equibrium. of.thermal formation and decomposi tion and thus gives a critical point for heating conditions. (4) Slight formation of PCDFs underj nitrogen may be due to oxygen gas impurities or the effect of water or' some other impurities-absorbed on the glass surface ENP 010309 783120 PCDF (300*C, n 02 , 1Week ) 783121 ATCAA Fig. 3 shows the gaschroraatogram of PCDFs in heated PCBs at 300 C under oxygen for 1 week. Major components were dichloro and trichlorodibenzofurans. Since major components of starting PCB mixture (Arochlor 1248) was tetrachlorobiphenyls, it is apparent that one or two chlorine atoms were released in the reaction. Therefore the following mechanism may be speculated. * Similar mechanisms are discussed in the earlier report on the PCD? formation during Ullman reaction for PCB synthesis (HORITA et al. 1977). ^ In analogy to the chlorodibenzodioxins, the, 1 ^ * toxicity of PCDPs is supposed to be structure highly? dependent as to the position and number of chlorines: 2,3,7i8-tetrachlorodibenzofuran might be the isomer of the highest toxicity. Peak no. 15 was confirmed to correspond to 2,3,7>8-tetrachlorodibenzofuran by co injection tecnique. The level was c.a. 8 0 pp m in the sample analyzed in Fig.3- It was noteworthy than the extremely toxic 2,3*7>8"TCDF was formed in heated PC3s. Yusho oil contained an increased amount of PCDF isomers but the isomer components were quite different from those obtained here. Major components in Yusho oil were tetra- and. pentachlorodibenzofurans while those obtained here were di- and trichlorodibenzofurans in spite that the starting PCBs were supposed to be similar in their chlorine content. Therefore other reaction mechanisms or subsequent reactions might be considered for the formation of PCDFs in Yusho oil. Heated metal tubings might be responsible to the difference. 783122 GENP