Document 5k9wydkb74pMEJYGeRYzeD3xe

Monsanto 'industrial cnem*.als company ,r^o* ft tocAiioHt R. E. Keller - South Second Street November 2 1971 . et: FDA METHOD FOR DIOXINS/PCB1S fttr mi MCI TO ; W. B. Papageorge - GO W. R. Richard - GO E. S. Tucker - Res. 7 1 St, Louis n /A': ^ The attached letter and pre-publication paper have been received from Mrs. Porter of the FDA. Recent press coverage in Food and Chemical News concerned this paper which was presented at the 1971 AOAC meeting. db Attach. R. E. Keller HONS 205988 DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE PUBLIC HEALTH SERVICE FOOD AND DRUG ADMINISTRATION Dr. Robert Keller Monsanto Industrial Chemical Co, 1700 S. 2nd Street St, Louis, Missouri 63177 Dear Dr. Keller: As requested, enclosed is a pre-publication copy of pur paper "Separation of Three Chloro-p-dioxins from Some Polychlorinated Biphenyls by Chromatography on Aluminum Oxide Column" which was presented at the 1971 AOAC meeting. The paper will be published in the JAOAC, November, 1971. Thank you for your interest. Yluouuars tLriuulxyy| CMrs.) Mildred porter Industrial Chemicals Residue Branch (BF-425) Division of Chemical Technology HONS 205989 Separation of Three Chlorodibcnzo-p-dioxins from Polychlorinated Biphenyls by Chromatography on Aluminum Oxide Column By MTIJJRKD L. PORTER and JERRY A. BURKE, (Industrial Chemicals Residue Branch, Division of Chemical Technology, Food and Drug Administration, Washington, D. C, 20204s - - Abstract The separation of 2,3-dlchlcn: odibenso-p-dioxin, 2,3,7-tri- chlorodibcnzo-p-dioxin and 2,3,7,8-tctrachlorodibcnso-p-dioxin from polychlorinated biphenyls by column, chromatography on aluminum oxide is described. Polychlorinated biphenjls were first eluted with 17, methylene chloride/hexane and the chloro- dioxins were then eluted with '207. methylene chloridc/hexanc. Recoveries of both polychlorinated biphenyls and chlorodioxins approximated 1007.. . HONS 205990 CjorwCSeparation of Three Chlorodiben?,o-p-dioxins from^Polychlorinated Biphenyls by Chromatography on Aluminum Oxide Column * ' By MILDRED L. PORTER and JERRY A. BURKE, (Industrial Chemicals Residue Branch, Division of Chemical Technology, Food and Drug Administration, Washington, D. C. 20204) Residues of polychlorinated biphenyls (PCB) are found in fish, bird and animal specimens from different parts of the world (1-2). Weatoo reported the presence of TCB with high frequency in refined fats and oils and foods of animal origin (3). These compounds are extracted and isolated along with pesticides and are detected by gas chromatographic (Gl.C) systems normally employed in analyses for chlori nated pesticides. Chlorodibenzo-p-dtoxins (chlorodioxins) may be found in chlorophcnolr (4) which are widely used in agriculture and industry, Chlorodioxins have been associated with the "chick edema factor" in by-product fat (4), .Some pesticide formulations have been found to contain certain chlorodioxins (5). The 2,3,7,8-tetrachlorodibcnzo-p-dioxin (tetra) has an extremely high toxicity (6). For this reason, analytical methodology for residues of the .chlorodioxins, especially the 2,3,7,8-tetrachloro isomer, must be capable of detecting very low residue concentrations. In tests to dc.termine behavior of tetra in multi pesticide residue methodology (7), we found a similarity of behavior of tetra and PCB (Aroclors ). Both were eluted from Florisil together and along with DDT and HONS 205991 o -2- ita analogs. The GLC retention time of tetra on DC-200 and mixed QF-l/DC-200 liquid phases was in the retention time range of the mu 11iccv.-.ponent PCS. GLC determination of tetra in the presence of I*CBVdj.d not appear feasible. Tetra was not resolved from p,p* -DDT on either liquid phase. Doth tetra and PCD were unchanged by reflux with alcoholic KOIt; p,p' -DDT was dchydroehlorinated to p,p* -DDE. Tetra and PCD were eluted together from a silicic acid column P with petroleum ether eluant. silicic acid column is used for the eru.'u j-' ty. cru.'u SC parotion of PCD from DDT and analogs. '7' ^ CLUsU- j-xrrr Wk-av The similarity in behavior of tetra and PC1> Z-yj&Wrrvl'fJ'<> ajr~^ ---- W'-'"----- . *- in the various analyt ^ . ical procedures and the frequent occurrence of PCB as a residue indicates a possibility of interference by PCB in analysis for residues of tetra and perhaps other chlorodioxins. Thin layer chromatography on aluminum oxide with n-heptane mobile AJn * ' * solvent (7) resolved PCB (Aroclor ' 1254) from tetra. Migration relative to p, p1 -TDL' was; tetra, 2.12; Aroclor^ 1254, 2.54, This suggested * . column choroatography on aluminum oxide as -o means of separating PCD, to permit quantitation of tetra by GLC, Experimental A number of experiments were conducted with different lengths of the aluminum oxide column and with different proportions and volumes of he.xanc/mcthylene chloride eluants to determine optimum conditions for separating tetra and PCB (Aroclor^1 1254). Further investigation of separation and recoveries included 2,3-dichloro and 2,3,7-trichIorn- dibun:;o-p-dio';i:is and Aroclors 1260 and 1262 , One ml of tetra (:;randru-d a) - HONS 205992 T`~ -3 plus one ml o PCB mixture (Standard c) or one ml of chlorodioxin mixture (Standard b) pInr; one ml of the PCB mixture were used in these experiments. Standard;; (a) 2,3,7,8-tut.rarhlorodibenfco-p-dioxin in hexane.--2.12 pg/v.rl. (b) Dioxin mixture in hexane .--2,3-dich locodibensto-p-d io>: in ; 1.50 ng/ml; 2,3,7-tr> rhlorodibcn/.o-p-dioxin, 1.28 ug/ml; 2,3,7,8teirachlorodi b.vnro-p-d io.xiu, 1.23 pg/ml. (c.) PCD mixture in hexane.--Aroclor'5' 1254, 0.16 ug/ml; Aroclor^' 1260, 0.16 |ig/>al; Aroclor 1262. 0.16 ug/ml. Rc.vp.ent s ' (a) Aluminum oxide..--Merck, "suitable for chromatogrophic adsorption", heated overnite in covered beaker in 130C oven and allowed to cool in desiccator. (1>) Ehiopt A.--1'A methylene chlori.de/hcxnne; dilute 1 ml methylene chloride to 100 ml with hexane. (c) Klunnl B.--202 methylene chloride/hexane; dilute 20 ml methylene chloride with hexane. Allow mixture to reach room temperature and adjust volume to 100 nl with hexane. Apparatus (a) Disposable pipeLs.--100 mm x 4 'nan l.d. (b) Micro evaporative concentrator,--No. K5G9250 with 10 ml Lube (K370050), Kontes Glass Co., Vineland, New Jersey, 0S360. (c) Car. cli renalo^rnph.--equipped with c ice iron capture detector and O' x A mm i.d. glass column parked with 37.,'OV-lOl on 80/100 mesh Chrcxnroib t."!:D. MOWS 205993 c -4- Operating conditions: N2 earlier flow, 120 ml/min; column and detector temperature, 200*C; injection temperature 225eC, Concentric design electron capture detector operated at d c voltage to produce 1/2 full (rr O -i' ' ' r: - I 1' -1 t 11 . '. . -9 1. The following paragraph Safety Precautions should be added following tus: Chlorodioxins were not weighed in the euthor'a laboratory. Ml work was done with standard solutions (ceo "Standards") fumJ shod if/ another TbA lal>oratory Safety glasses and disposable plastic gloves wore worn. I.;ot:ch tops were covered with disposable adsorbent mats. The effluent from tho electron capture GLG detector was passed into trap containing corn oil. Sar.ple concentrations were carried out in the hood. Gloves, towels, mats, pipats, containers of solution, and alunimm oxide columns wore placed in plastic hags at the end of each experiment. Scaled bags were picked up weekly for incineration. hexane solution containing PCB and chlorodioxins was added. Walls of the chromatographic tube were rinsed and the column eluted with a total of 6 ml Eluant A (1% methylene chloride/hexanc). Eluate A was concen trated to a suitable volume, using a micro evaporative concentrator ami analyzed by electron capture GLC. Recovery of PCB approximated ]007.. An additional 1 ml of Eluant A was passed through the coluirn *. - and the eluate analyzed separately. No chlorodioxins or TCB v;ere present; , The receiver was changed and the column eluted with 6 ml Eluant 15 (207. methylene chlovide/hexane). Eluate B was concentrated and analyzed in the same manner as Eluate A. Recovery of the three chlorodioxin isomers approximated 1007.. An additional 1 ml of Eluant B was passed through the column and the eluate analyzed separately. No chlorodioxins were present. Results and Discussion The separation of PCH (mixture of Aroclors' 1254, 1.2G0, 1262) from cl: ii rod ion i:i i :-.l >i rn cl 2,7-ri2 , .1.7 - S' V i , .':ul 2,2,7 , ft* I o t r;:i h ! erod i Vn ' h-dinxin) on a column of aluminum oxide was complete. The PCX> were first HONS 205994 -5- c]uted with 6 ml 17. methylene chloridc/hcxanc and the chlorodtoxins were then eluted with 6 ml 207. methylene eh lor ido/hexan'e. Recoveries of both pCb and eh 3 uio.l ioxins approximated 10071. No difference in separation or recovery was observed with acid, basic, or neutral aluminum oxide from three ni.aru far turors . Retention tiroes of the chlorodioxins relative to aldrin at the. C3.C conditions described under apparatus were; 2,7-dichloro, 0.93; 2,3,7*d irlilor o, 1.67; 2,3,7,8-tetrachioro, 3.0. Approximate quanti ties of the chiorodioxlns required for one half scale recorder deflection nt the GLC conditions described under apparatus were: 2,7-dichloro, 40 ng; 2,3,7-dichloro, 20 ng; 2,3,7,8-tctrachloro, 16 ng. Response tended to improved (r.rmllcr quantity for 1/2 scale recorder deflection) with use of the GLC column. Summary Separation of PCB from chlorodioxins was achieved by column chromato graphy on aluminum oxide. This technique should be useful in analysing samples containing PC11 for residues of the chlorodioxins, Acknowledgement t The authors wish to thank Dr. David Firestone and his staff, FDA, Division of Chemistry and Physics, for furnishing standards of the chlorod ihenao-p-di.oxins. HONS 205995 References (1) Penknll, D, U, and Linccr, J. L., BioScicncc 20, 958-964 (1970). (2) Reynolds, L. M., Residue Reviews 34, 27-57 (1971). (3) Uustdd, G., Norcn. K, Anderson, M., Var Foda, Fodoamneshygieniska avdeIn logon Vitarnnnvdelingen 2-3. 10-31 (1970). (4) Higginbotham, G, R., ct. al, Nature 220, 702-703 (1968). (5) Woolr.on, E. A., and Thomas, R. F,, Abstracts, 161st National AGS Meeting, hos Angeles, California, March 29, 1971. (6) Spnrschu, G. L., Dunn, F. L. and Rowe, V. K., J. Toxicol, and Appl. rhan^col. 17.(1) 317-318 (1970). (7) Pesticide Analytical Manual, Vol. 1, Food ami Drug Administration, Washington, D. C. 1968. Revised July 1969, July 1970. 1 (>) Armour, J, A., and Burke, J, A,, JAOAC 53, 761-768 (1970), (,^), /^, , f[ to, f b*-, Pt , //` -S ^ t-V-tA.** tv tL rf2 'Zo` (WfJ HOHS 205996