Document GK9Nq9ZYDoLqa1mEyYnekxxV4

Tf? ;ij (<fj*./ ,xi Identification end Toxicological Evaluation of Chlorinated DiUonsofurau and Chlorinated Japhthaleno In Two Coixicrcial Polychlorinated Biphenyla* J.G. Von. Inotituto of Veterinary Pathology, Biltstraut 172 Utrecht Tho rotherlandu* J.il. Kocman and ii.L. van dor Kano* Inotituto of Voturinary Ifcoriar.oolccy end Toxicology, Biltotraat 1?^, Utrecht, Tho liothcrlondc. IUC. ten Hoover do Brauv. ii.H. da Y03 Central Inotituto for Imtritiun and Food.Reco&rch, TKO, Zoiot, Tho Ilothorlr.ndo* \ Xtunnlnc title: Toxic Inpuritlcs in toclnioal J'CiJ preparetiono. Nev 036689 2 < Abstract In a provloua otudy (Voa & Kooauu* 1270) a significant difference In toxicity vac found uotween J co.r.iorcial IC?J propuratione; high nortclity livor necroaia and c!iiol; oodona-liko leuionn occurred In 2 0-3*a. In the present study It wno round by r.onna of column chromatography and cc.z ciirouafcogivv-liy, that In tho 2 diethylother fractions of theso 2 PCU'o polar coupounda aro present# A chicken embryo aooay proved the high toxicity of thio fraction. Subsequent r(ati3 cpectronotrlo and ^icrocoulor.'trlo analyse a revoalod tho identity of thoue coupoundoj a.o. totra- and pentachlorodiuonzofurun* The oignificouca of theue iupuritioo arc diocuaood. It io concluded that evaluation of animaluorporiaenfco with PCh's io cxtreiicl:y difficult due to tho prooonce, of chlori nated dlbenzofurc.no in oouo commercial PCJ'a. p NEV 036890 Introduction l'olychlorinatcd biphonyla (ICE) have boon identified In tissues of fiah and wildlife (janc&n, 19665 ilolnGo, Jin^ons & X&tton, 19671 Golden & iicrodexi, 19671 Koonan, Ockunp, Veen, Brouwer, Hooth, Ewart, van do Brook & van Conderen, 1967? Risotrough, Eiocho, roolcall, Homan Cc hirvon, i960? KoBMnn, tor hoevor da Brnuw A do Von, 1959? Jenson,- Johmils, Clcsoa h .Ottcrlind, IS69), and have been roosiitly boon inplioatod In the mortality of ecu birds in Britain (Bourne k Head, 1969) Coaaoroial FOB proparation0 aro oxtrocoly a table end only slightly eolublc in water- They ora usod aa lubricants, 33 heat t-canefor media, in protootivo coatings Tor wood mua metal and oonexote, end in many othor applications* Thoy urc compatible with paints, synthetic rosins, Yamlshoc and waxes, and improve ouoli properties of thoco products ac their chemical resistance, vator roolctanco, edhcoivonooo and flexibility (Anonymuo, 1960? liubbaxd, 1964). JloA'or, it has not yot boon established which of tho iatcriiJ.0 treated with Ch liac contributed to the present environmental contamination* Experiments with rats and guinea pigs knvo chov;n that the ingestion of TCU nay giva rise to livor injury (iiilior, 1944) llydroporicurdiun, occasionally acceupaniod by abdominal oodciic, was found In oliioko (iteCuno, CavagG . O 'Boll, 196c? Filer., O'fcll u Childs, 1969$ Vos 1 Koeuan, 1970) and Japuncco quail (ioenau et al*, 1969) after ingestion of i'UB of American (Aroclor) and Frouc)i (rhenoclor) origin, respectively A narked roaoafclancc between the gas chnrouato^rcas and nc.cs spectra in naco spectror.otor eumlycoo of 9 eocir-orciol ICE propagations (i-hcnoclor BF6, Ciophen ACO, mid Aroolor 1260) was found ('Joetan et al., 1969) Tbs occurronco of "ihiok oedema" like lesions in birds fed VCIS (Koonan ot al*, 1969? HoCuno ot ol, 1962? Flick ot al 1969) was NEV 036d9l 4thc rocxon. for a recent cooperative toxicolocicd test with tho 5 ncntior.cd PCJ) preparations in chickens (Vos & Kocnan, 1SJjo)* In thic study a significant difforenoo in toxicity botucon tbo j$ tooted ooopoundo vco, foundf Clopfcn A60 and riionoclor DP6 chouin^ tho highest, Arotlor 1260 showing tho lowest nortality. Subcutaneous and ubdoniuol oedcuu, end ccntrolobular liver nccrocio was recorded o:0Ly in thouo ohicho fed with Clophbu end Phcnoclor. Hydropc-ricardiuri vau recorded In nearly all oliichu fed with Cloplien and Fhonoclor and oiily occasionally in chicks fed with Aroclor. Ghomical porpliyrlu vua found as u general PCD effect. In the present study, tho sexual to that Mentioned above, wo dosoribo tho idontifioation and evaluation of oornpounde rooponoiblo for tho difforonco in toxicity botvoon tho 3 oonnorolal PGB preparations NEV 036892 I lir.pnrit io n tr.l Tho PCB preparations, which contain an uvora^o of Co/* chlorine, were obtainod iron frodolcc, Franco (ifcanoolor j>4). Bayer, Oorraany (Cilophon A6G, Lot no. 912434)i ^ d Monsanto, u#:3.A, (AroeXor 1260, Lot no lt-3). Th screening oethod, used for dotootion of chick oederaa factor (Anonymuo, 1960a) v/aa nodlfiod and used to isolata from the .PCB propasutiona, conjpound(o) responsible for dlfforancoa in toxicity. Tho oloan-up ctop of this procedaro vaa onittod In the oolunn clircanto^raphj Og actlvatod fierioil (ooluran 1Gnu) was uood Instoad of 133* activatod clunlrta. For fraotienation rcclijd, . hexane wag uocdag_elution solvent inotoad of pstrolcuia ether Two mg1PCD v;ao diesolved in 2 ol iioxcuio and fractionated on the florioil column. This colunin uaa elated vlth hoxano until noarly all PC3*o wore oluted (tactod by gas. chromatography) Tho 2nd fraction {*}/> dicthylothor in hoxano) vao alco tooted until no uoro PCS could bo dotcctod. Tho final fraction (fraotlon 5), olutou with 25# diathylothor (roaoont grade) in hoxano, woo ovuporatod to 1 ril An aliquot of this conoontrato vao injoctod into a 204-1B Vardan Aoro^aph gaa ohroaato(rroph with oloctron capturo dotootion* Tho Fyrox glnon column (> foet x I/O inch), filled with 10/i DC 200 on Gaoenrom v* (80-100 rxsnh) was oporutoa at 2C0G with nitio.von no oorfior gas (about 0 nl/nin.)# Tho goi-o procedure was used .to fractlonato aliquots cf about r.c of tho POIi preparations in order to obtain sufficient quantitice for p. chicken embryo assay and for nr.os opoctroneter anolysoo. Tho PCB was dissolved In 200 nl hexane, The coliLin (0 32 cn) vaa filled with ieo c activated florioil The nore polar conpoundo were eluted in tho final (3rd) fraction and, after evaporation, tooted by^gao cliror-atogruphy A ohlokon onbryo aocay (Verve jlurliac u McLaughlin, 1964) vao used to dotoruine l;ho toxicity of tlio 3 FC3 proporationc, NEV 036893 (donoj ->#5 diocwlvod and kept at 37C in ethanol Croup 1 Aroclor, group 2 rhouoclor and group 3 * Clophcn) and of tho 3rd fraction of Clophcn (doeoi 3rd fraction obtained fron 35, 3,5, and 0*35 a-nd 0*035 Mg Clophcn in groups 4* 5 e and 7 respectively), The uoaplos, after diaoolving in 0*03 nl ethanol wove injected into tho air coll of froah VTnite Leghorn eggs prior to incubation* Vho livo:%o 11 hatched chicl: were renoved for histological crimina tion* fixed in 10/j buffered fomalir. and procooscd in r. conventional wanner* Moreover, cryostat eootiona voro Gtudiod in a fluorooocnco niOJTOOCOpO* Kang opootronctry wao unod to identify conpomulo prooont in tho polar 3rd fractions* Thio analyoio van carried out uoing a gao ciironatograpii-nacD spoctremoter combination* For thin pnrpono a CII4 ntiss opcctronotor (Vnrion Hat* 0*n*l>*H) was coupled to a Varian Aerograph ovon, typo A5503, with a iyrox ciaoo colunn (5 foet x 1/G inch) filled with 10/j DC200 on Oaschron U (C0-100 nosh)* M.irtioulnr attention vao paid to the denigh of tho interface botuoon . tho gas ohror.atograph and the naoo apsetrouoter in order to obtain tho beet operating conditiono (ten Hoover do Drauw & Brimnde, 19^>T} High rooolution naao opootra wore taken on a double focuo opcctro- notor type Si!^ (Varian IJot* 0.ro*b*li* ) Exact naoo noaGureasnta wore done with the peak 9 natohing nothod (ibaourooonts wero aloe done fron spectra which wore recorded cu photographic plates proceoncd MtV 036894 "by Varian Hat* on a I.citz comparator 3ATI1). To obtain information about ths quantities, nicrocoulo- notrio analyses cf tho 3^d fraetiono wero earrlod out* Tho equip* nont uoad wao a Pohroc.rm zcieroeouloisotor, coupled to a liicvotek 1-IT 220 gao ehroraatograph, with a glass column (6 feet x inoh). The acme 10;$ DO 200 column packing was uood* The colurui offluonts voro oxidized in n Dohrmann coabuotion furnace and tho HCt, produced by chlorinated compounds, was detected and quantitatively ne\our3d i`x ^ ii r flooultu 111 rocultiug gan ciironatocraw of fraction 3, obtained with tho snail eolucn (0 10nn) rovoaled too prooonco of polar compounds In Pbeuoclcr and Clopfcon ), Thoac voto not found in the Aroclor extraot. Tho oamo results voro found with fraction 3 obtained with the large column (0 32 ram). The 3rd fraction raised of Clophen vao cubcctmontly uned in the chdo!<o:i orfcryo assay. Thlo nooay (table l) confined the differences in tonicity between the 3 tooted FC2 prepare,tious found in the previous study (Voo koGman, 197J). Ilortality in roup 1 (Arcelor) did not differ eignilicantly (X2 tost) fron mortality in croup 9 (control). Mortality in croup 4 end 3 is dodo rclatod; ourly mortality in tho former, scattered mortality in tho latter croup. Corresponding mortality in group 3 (3S Off Clophen) and croup 3 (3rd fraction fron 3*3 Clophon) indicates atrongly-thas the polar rosiduo in the letter dotcrainoc tho toxicity ofe tho comaorolol PCI! ^Jlnccotion of all frooh enbryoSand of the one-day*old ohloko revoiilcd no abnomnlltloo oxcentj for ono onbryo of group 3 kick ohowed,n. covers cubcutonopuo oedema. Ootlona end bool; dofciialtioo nro daciorlhed after yolk, nac lujaotion of 23 du and 10 mg Aroclor 1 P.42, resulting in roopcctivoly 100/ and 95/^ ombryonio mortality (ltcbnughlin, tlnxllac9 Yorrolt Uutchlor ? Fltshugh, 1903) d.l;. stained liver oeotlonc xuvoolod no norphologic altorationo. In the cryostat section of tho liver of tho only hatched voah chicken of group 3 a rod fluorooconca in eona lobulea rao oc.ni in tho u.v* L\lcxonco;e. Tills fluorescence io indicative of tho porphyrin biooynthorlo dloturbanco found in the prior study (Voo Keenan, 1970). Ilasa oijoctrowetrio analysis revealed identical chlorinated eonpoundo in fraction 5 fron Phonoclor and Olophon in contrast with Aroclor. Tho rosuits are given in table 2. iluon spectra of compounds with mauo number 304 id 330 obtained fron pool; 1 and 4 aro given in fig.2 and 3* Fron exact oaao noasuronontn It was found MEW 03^893 that tho formulas of tho molecule poako 304 end 330 were C: CL And CjJI-O^CIr 'lho formulan of the fragment lona 241 and 275 wro C ^ U ^ O l - end 0^II^JC1^# From this cota t oon to concluded that the parent Ion has n preferential ftabsen tation for tho loor of a ningls ClCO 'mitt iano spectra were coispssed with the epoctxun of e compound inolatod from toxic fat (V/gotton Cv Courchenot 164)* Subsequent otudy, using X-ray diffrac tion, hco rove sled that the identity of one of the toxic factora vuu 1f 2, ?# 79 C 9-hc::achlorodlbenco-p-dioxJ.n (Wootton U Courchsne 1964)# 5ho naoo-opectriu of this compound hen r> oinilar fragenbati pattern io* loo of puococoivo 2 caos unito 63 ouggeota r loss Of 2 C1C0. unito nicrocoulo&etrio ariulyceo of tho 3rd fraction of Clophon end Kicnoclor revealed oVoronato^raJUc with tho anno poak pattern as in flg1* ?ho "pcnl;11 of tho totraohlorodibongoffuran (mano number 504) io too uaokod by tho proximity of the hoxacliXoronuphthnlcno peak (peak no*2) to m h o cuantitativo calculations poauiblo, for similar roi'.uou peak no 4 in tho ciironcito.vxmi, found to bo a Mixture of heptaobiorobiphcr.yl and pontachlorodibonsofuran, could not bo reueurod direotly* However, when ntnmuinr; that the wholo peak io jjroducud by the dibonnofurea compound alone, a curtain tiuxii-uu level cau bo iudicniod* This level uuo found to be 5 ppn pentachlorodlbu'.isofurcn ill Clophcn mnl '0 ppm in rhenoclor# Uowovor the iainiituu level could bo indicated with the- cotit-atod lower U n i t of detection of tho maco opectronotria equipment* Under the condi tions uoou this level wao 1 ppm* NV 036896 ^0* I Discussion Jiaus spoctronotrio recults have not conclusively proved the identity of the clilorinatod dibensofuraus* Dut cyathosia of thooo compounds, nocoosexy for comparison vith the mass epoctra obtained experimentally, vao found extremely dangerousj a cin^lo oral, dooc of 05*1*0 n '-jV.z tri- and tetrachlorodibohsofuran caused severe and often lethal liver necrosis in rubcito (Bauor, oc'.iula & SpiaijclL'cr^', 1261; xiof"w;m, 193-0* Application on the oar of o rabbit resulted in cbloraonc (Bauer ct d. , 1901). lUe reiatod compound 2, }$ 71 C-totrachlorodibonzo-p-dioxln (following tho description nf Chemical Abstraoto), which nay appear in tho oyntheoio of 2, 4t 5-trichlorphenol by hydrolysis (under prosours and with tho precorieo of sodium hydroxide and mathanol) of 1 2, 4 S-totrachlorobenzeno (Bauer et nlt 1961)1 usually caused a lethal liver neorooia in tho rabbit after a oinglo oral dose of 0 05-01 lac/k" Bor application also in a 10 tinsc lover dose oonparod vith clilorinatod aibonzofuran, resulted in chloracno (Bauer et al, 1 $6 1; Linn Jonoo s Krlsek, 19$?.) 12,5,7 f'3#9-i-C?xachlox'ouiben&o-p-dioxiu, which can ariso in tho pyrolyoiu.of 25,4,6-totrachloropIicnol (ilictiinbothMi, Huang, 1'iroctor.o, Verrett, Eeoo is Campbell, 1pC0), hco born isolated end identified ns o:?o of tho toxic ov.batancon of tho Cliioh Codera factor (Vootton 1 Courohone, 1964* Anonyuuc, 1960b) Tho relationship between tlio toxio nature cf PCD and tho Chick Ccdoiia factor hno already boon discussed (flick ot ul, 1965)* Air coll injection in chicken cs of 005 ug he:ca~ nortality chlorouitonso-p-dioxin resulted in 10Q/> embryonic (lllcclnbothera ot til* 1 96U} Wie exporicant using an injection of tho 5::d frootion obtained''55 mg Cloption into the air. cell rcoultsd in 100>/ normality (tablo 1) It can bo oalculatod that tho ncximuu Ni=V 036697 dooe/oGC io 0*8 vlq penfcaohloxodibonsofuran (using a valuo or nwc. 5 ppa). Tlilo confirao tho order of toxiolty discussed abovo The combination of toxicological, pathological and ohonical analytical data calcos it almost cortain that tho compounds of nass numbers JO4 and J33 axo rospootivoly totraand pentnohlorodibonsofuraa. Tlic origin of those toxic factors In Clophen A(50 and Phonoclor DP6 can possibly be oxplalnod by differences in manufacture. Particularly In tho distillation procoduro of orude PCD, in vhicli ccdlun liydroxido con bo usod (Pay & Htchord% 1947) PCB reacts vitli oodiunhydroxlde at olovated tenporaturoo to ylold plieziollo conpoundo, e.g. PCD is eaponiflod into polyulilorohydroxybiphonylo by coons of eodiua hydroxide in a polyhydrlo alcohol niadiun (Anonyaus, 1957) A further loos of hydrochloric sold could produce dlbcnsofuxan derivatives. . Chlozlnatod naphthalenes are far loss toxic than ohlorl* natod dibonsofurano (iiofnann, 1950). Slioroforo the lattor nay be assumed to dotoraino tho toxiolty of fraction 5* Tho ooourronco of hydroporioordiua in chick fod with Aroolor (Pliol: at al.9 1963), nay indloato tho prooanco of a vory snail quantity toxic factor. From tills study it is concluded that evaluation of PCD xosiduos In vildlifo oninalo, bacad do on offoots and residues in tost anlnalOf is oxtrenoly difficult duo to differoncou In toxiolty between ConnercibA PCD preparations. Work is in progress to dotcat and identify chlorinated dlbonzofuran from vildlifo opoolnons. 0363^8 nev Acknowledgments * Ve acknowledge the contribution of Hr EWA# Kaaperdijk and Hr* P.P llijkfuap* and the technical aaolstanoo of Itr* J.H. Pcnnl ?hlo investigation, vao supported by a crant from tho Central Organisation for Applied 3olontiflo Roooaroh (T*H.O.) which made it posolblo to accomplish tho masa opootra onalyoos NV 036699 Roforoncoa Anonyimo, (1957)* Method for producing phenolic eubatanoao through tho treatment of ohlorlnatod diphonylo and polyphonylo and oubatanceo obtained thereby Brit Fat 77? 221f July 17 (to Frocil)* Attonynuo, (1960) Aroolor Plaetioisoro Monsanto Conpany Tooh* Bull ,no* PL--306* Auonynuo, (1960a). Changes in Methods 26. Gila, fats and waxes J* Asa* Offlo* Anal* Chon p1 409-490 Anonyauo, (1960b)* Tho chick cdena factor Kutr* Itov* cC, 20-30 Bauerj U.f Sohulc, KH* & Spiogolborg, U* (1?61). Boruflioho Yercif- tungea bol dor Heratollung von Chlorphonol-Vorbindingon* Arch* Govorbopath* Goworbohyg* 18 530-555* Bourne B# 1 Hoad, C* (1969) Seabird olaughtor* BT*0* Howe, ed. by Koith Clark for tho BritioEUI'or Ornithology, no 36* Fay JW,J. & JUchordst J.H (1947)* Inprolanto used In German papor capaoitoro Office Tech Sarv FB ropt. 7559i BIOS Final Itopt 893* Flick DF O'Doll, H,0. & Childs, V*A (1965) fitudioo of the chick odona diooaso. 3 Similarity of oynptoas produced by feeding ohlorlnatod biphenyl Poultry Gci 44 1460-1465* Higginbotham, GH Huang, A, Flrostone, B Vorret* J., Boos J & Campbell, Al). (168). Choraleal end toxicological ovaluationo of ioolatod end oynthotio chlorodorivativoe of dibouzo-p-dioxin Nature, 220y 702*703 Jlofuann, II.Th- (1950)> Nouero Brfahrungcn nit hoohtoxischon Chlorkohlenwnocorotoffen* Experincntelle Pathologic Phnmakologio 232 220-230 Holden, A.V. & Ilorodon, K (1967). Organoehlorino peotioidco in cools and porpoloos Datura 2 16 . 1274-1276 NEV 036900 __ . *, .. .-**, * * OlO * WlXorjLil--tafcia hydrocarbons in British wildlife, Hatuxe, 216 . 227-229, Hubbard1 H.L* (19^4) Chlorinated biphenyl and related compounds. Encyclopedia of Chemical Teclmology, od. by Ellor Kirk* A, & Othmer, D.F., 2nd rev. ed., 209-297. Jensen* 3. (1966), Deport of a new chemical hazard, Dew Sci. 3 2 , 612 Jensen, S. Johnele, A.G., Oleson, II. & Otterlind, G. (1969), DDT and PCB in marine animals from Swedish waters, Nature, 224, 247-250. Koeman, J.IU, Oskamp, A.A.G., Voen, J,t Brouwer, E.f Booth, J., Zwart, P., vd. Brock, S . & van Genderen, H,,(1967). Insecti cides as a factor in the mortality of the sandwich tern (Sterna sandviocnoio* Iloded$RiJk3facLandbottwwetonaohappen Gent, 32^ 841-054. Koeman, JH,, ten Noovor do Drauw, II.C. & de Vos, B,I1. (1969), Chlorinated.biphonylo in fish,, mussels and birds from the river Rhino and the lTetherlcnda coastal area, Nature, 221. 1126 -112 0 . Linn Jones, E, & Krizek, II, (1962). A technic for tosting acnegenio potency In rabbits, appliod to the potent acnogen, 2,3,7,G,- tetraohlorodibenzo-p-dioxin, J, Invest, Dermatol, 59. 511-517 UoCune, E.L*, Savage, J.E. & O'Dell, B.L, (1962), Hydropericardium and ascites in chjcks fed a chlorlnatod hydrocarbon. Poultry Sol. 41, 295-299. MoL&ughlln, J., Harliao, J., Ferrety 21.J., Ilutohlor, XI.K, & Fitzhugh, O.G,, (1963). The injection of chemicals into the yolk sac of fertile eggs prior to incubation as a toxioity toot, Toxicol, Appl, Pharmacol, j, 760-771 Hiller, J.W, (1944). Pathologic changes in animals expocod to a comnoroial chlorinated diphenyl. Pub, Health Hep,, ^9^ 1085-1093 NEV 036901 HifeGbrough B.W* Mocho. F* Fookall. 3)*3M HermanF Q.C. & Kixvon HH* (19^8) Folyohlorinatod biphcnylo in the global ecoeyotam. Mature 220 1098*1102. 5on Hoover do Brauw, H.C. & Brunndo C.Z. (1967)* Krcobnioao uit elner ojptinicrton lloppldng von Qas Chroiaatograph und laooenapoktrouetor. Zoitsehr. f. Anal. Chon. 229. 321*338 Yerrett1 H.J. KarllaoF J. A JlcLougljlinF J. (I94). Use oX the cliiokan cabryo In tho aoaay of aflatoxin toxicity. J. Ago. Offio. Agr. Chon# j^j;tf1003(*1006. Too J.0. & Kooia&n J.U. (1970)* Corporativo toxicological atudy with polyclilorinatod biphenyld in chichona with apodal roforouoo to porphyria adona foruatlon, livor nocrooin and tioDuo roaiduoo. Toxicol. Appl* Fharuaeol In proaa. Vootton J.C. d> Courchono V.L. (1964)* A contribution to tho knowledge of tho otruoturo oX tvro hydroporio&rdiun-produoing fnotora from a toxio fat. Agr. Food. Chon. 12i*94*90. NEV 036902 `Taille 1 Chicken Enhryo Assay or Chlorinated Eiphenyls Aroclor 1260, Phonoclor DP 6 m A Clophen A60 and tlio 25 per cent Dlethylcther Fraction of Clophen a 6Q* Group Compound Dose/oga Iftnber Eumber of >Por oont Hatch Infertile Eggs gf Fertile Eggs . Renarka 1 Aroclor 1260 2 Phenodor DP 6 35 off . 15 3.5 off 15 3 Clophen A 60 3*5 20 4 Clophen A 60 Jr fraction of 35 mg 15 5 Clophen A 60 6 Clophen A* 60 n " 3.5 ns 0.35 os 15 15 7 . Clophen A 6 " O.055nc 15 8 Ethanol 20 9 Control 20 0 0 1 0 0 2 2 2 0 60 0 5 0 7 92 100 94 90 Kent cabryoo died during firs half of incubation period Most oabryoa died during fixe half of Incubation period All enbryoo died during first four days of Incubation porio * Most embryos died during fire half of incubation poriod v. The samples, dissolved in 0.05 nl ethanol, vere injected into the aircell of fresh eggs before Incubation NEV 036903 Table 2. Retentions and Collected Mass Spcctromotric Data of the Peaks in flg.1. Peak no* Relative rtention& liass nunber(s)^, and msnber of chlorino-tonB/nolecule Identity of the conpoond(s). 1 1.40 2 1,53 3 1.74 4 2.42 5 5.48 JC4(4C1) 332(6) 350(6C1) 392(7) 538(5) 592(7) 366(7) tetrachlorodibcnnofuran hexachloronaphthalene hcxachlorobiphcnyl hoptachlorobiphcnyl pentachlorodibenzofuran lieptachlorobipheny1 heptachloronaphthalcne dtention related to dieldrin 1 ^Macs nunbcr calculations bsed on Cl 55 NfcV 0 3 o 9 0 <*