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to O G o .c a o U O JS CJ G 01 h ai ai cl CS h ni Xw 0 H 01 *T3 01 1 ai ao io H OM H N CL C - Q'O >.za c (U -H 3 -H a (0 H >c o i ai -3 aj c (fl Q] C JZ *H CL LO O -u <~l C U W O .. X UJ 3 < KO I co en I c\ ri CO oO Z cl uj > a. REPORT NO.: ES-79-SS-6 JOB/PROJECT NO.: 4 3 -0 0 0 -7 6 0 .26-400344S DATE: June 26, 1979 Confidential-Subject to Protective Order. TITLE: Chlorinated Dibenzo-p-dioxins in Chlorophenols, Santophen-! and Process Samples AUTHORS: PERSONNEL: R. G. Kaley, II G. W. Butler, MRC; J. A. Dixon, MIC; D. Douglas, MRC; 0. Hicks, MIC; F. N. Hodgson, MRS; R. G- Kaley, MIC; D. Kirk, MRC; A. Wright, M] ABSTRACT: Analyses of various chlorophenols for trace amounts of chlorodibenzodioxin are presented. DISTRIBUTION: D. C. Armstrong - 1740 C. F. Callis - B2SA D. B. Edwards - B3SD E. L. Head - B3SB J. A. Hinkebein/D. P. Roman - N2B R. G. Kaley, II - T2F H. W. Kilbourhe - N3A J. S. Metcalf - B2NK D. P. Metherd - 1740 J. P. Mieure/R. L. Wasson - T3B J. D. Wilson - N3A Technical Repts. Library R2C RESTRICTED DISTRIBUTION - DO NOT COPY ! CO 0 4 7 COMPANY C O N F f D E N T. I. A L This document is the property of Monsanto Company and the recipient is responsible for its safekeeping and disposition. It contains CDNFinPNTiAi f1 INTRODUCTION: Cg;.uoentia! -Subject to. Protective Orderl^ ^ , . . ..-j On Jan. 11, 1979 a derailed tank car spilled 20,000 gallons of crude o-chlorophenol near Sturgeon, Mo. Analysis of a retained sample of this material indicated the presence of chlorinated dibenzo-p-dioxins, including at least one tetrachlorodibenzo-pdioxin (TCDD) isomer. Subsequently, a program was initiated to determine the levels of chlorinated dibenzo-p-dioxins in process samples and products and to establish the source of the dioxin contamination. Further, process changes were evaluated at the W.G. Krummrich Plant to determine the effect on the impurity levels. SUMMARY; Product and process samples from the chlorophenol and Santophenl processes at the W. G. Krummrich plant were collected by plant and D6P research personnel. These samples were submitted to MIC Environmental Sciences (MIC-ES),who coordinated analytical work with Monsanto Research Corporation (MRC), Dayton, Ohio. The results have shown the presence of chlorinated dibenzo-p-dioxins in many of the process samples and chlorinated phenol products and in several Santophen 1 samples. A process change was initiated which eliminated a caustic distillation from the chlorophenol process. Early indications are that this change has reduced the level of chlorinated dibenzo-p-dioxins to below the detection limit of the current methodology. ANALYTICAL METHODOLOGY The method used for the determination of the chlorinated dibenzop-dioxins in the samples has been previously described (Mieure, J. p. et a l , J. Chrora. Science, 15, 275 (1977). (Attached) Modifications were as follows: A) Apparatus - step 5 - the GC column was packed with 3% OV-101. B) Procedure - step 1 - the 5 g sample was dissolved in 50 ml of 10% methylene chloride in hexane. A 5 ml aliquot of this solution was added to the macro-column and eluted with 10% methylene chloride in hexane.' 10% methylene chloride in hexane was used as the rinse solvent ,when transferring the sample to the concentrator. The eluate was concentrated to approximately 0.3 ml. C) Procedure - step 2 - the entire 0.3 ml concentrate was transferred quantitatively to the micro-column. 2 D) Procedure - step 3. A. - the 50% methylene chloride in hexane fraction was evaporated to approximately 0.2 ml for GC/MS analysis. No chlorobenzene was added. Detection of the chlorinated dibenzo-p-dioxins was by gas chromatography -- mass spectrometry. The method was developed for the analysis of pentachlorophenol. However, its suitability for analysis of mono- and dichlorophenols and Santophen 1 was established by spiking TCDD into various samples. Details of the accuracy and precision are in a subsequent section. CHLORINATED DIBENZO-P-DIOXINS IN SPILLED O-CHLOROPHENOL A reserve sample of the crude o-chlorophenol spilled at Sturgeon, Mo., was analyzed for chlorodioxins by MIC-ES. The sample was identified by the following designations: GATX 12932 KL 2 8001-1 1/7/79 MIC-ES Log 901*0701 A sample of o-chlorophenol from Fisher Scientific Co., Lot 776410 was analyzed concurrently as a blank. In addition GATX 12932 and the Fisher material were submitted to MRC as ES-11 and ES-12, respectively. The results are in Table 1. DETERMINATION OF CHLORINATED DIBENZO-P-DIOXINS IN CHLOROPHENOL AND SANTOPHEN 1 PROCESS SAMPLES Following detection of TCDD and other chlorinated dibenzo-pdioxins in the reserve sample from the Sturgeon spill, samples were collected from the chlorophenol process to identify the source and level of contamination. These samples are identified as MB 655-696 and ES-1-51 on the sample identifications in Table II. Results of the above analyses indicated the source of the chlor inated dibenzo-p-dioxins was the caustic neutralization and distillation in the chlorophenol process. A process change eliminating this step was made a n d 'further samples were submitted These are identified as MB 704-43 and ES-52-90- Preliminary results suggest the process change has reduced or eliminated the chlorinated dibenzo-p-dioxins in the chlorophenol process. Although some samples were analyzed by MIC-ES, most were coded by MIC-ES and forwarded to MRC for analysis. The results of those anlyses are tabulated in Table III. (Analyses performed by MIC-ES are designated by'*.) i 3 Confidential-Subject to Protective Order The data for TCDD in Tables I and III are total concentration of all isomers in each sample. The only isomers for which MIC-ES has standards are the 1,3,6,8- and 2,3,7,8-TCDD. These materials have different GC retention times under the conditions of analysis/ so discrimination is possible. Figure I shows the separation, of the two materils in a standard mixture. Table IV shows results for analyses by MIC-ES for which "isomer distri bution" has been done. TCDD was reported as two groups: 1) isomers which elute at the retention time of 2,3,7,8-TCDD and 2) those which elute at other retention times, including 1,3,6,8-TCDD. These levels do not imply that the compounds have been identified as the isomer in question, only that there is retention time agreement. It is evident from these results that isomer distri bution does vary from product to product. Quantitation was by an external standard method using a mixed standard of available chlorinated dibenzo-p-dioxins. No standards were available for the mono- and pentachlorodibenzo-p-dioxins, so response factors for these materials were estimated. Chlorophenols from outside Monsanto were analyzed as "blanks" during this study. The results for these materials are in Table V. The material designated Fisher OCP is probably the best material for a blank for these analyses. During the course of the study the samples were also analyzed for chlorinated dibenzofurans. However,, recoveries of spiked tri- and tetrachlorodibenzofurans by MRC were low, so the data for the chlorinated dibenzofurans is not valid. No results are reported in this study. ACCURACY AND PRECISION The accuracy of the determinations reported in this study was determined by fortification (spiking) of selected samples with known amounts of chlorinated dibenzo-p-dioxins. In almost all cases 2,3,7,8-TCDD was the material used for spiking. These sets of data relevant to this study were divided as shown here; Spiking Lab Analvsis Lab Table I MIC-ES MIC-ES MRC MIC-ES MRC MRC VI-A VI-B VI-C The recovery data are reported in Table VI as indicated above. Table VI-D contains recoveries for one sample (MB 654) which MRC spiked with a mixed standard. \ P frfc r T ^ X J I3 S~ '- 18 - Determination of Trace Amounts of Chiorodibenzo-p-Dioxins and Chiorodibenzofurans in Technical Grade Pentachlorophenol J. P. Mieure, O. Hicks, R. G. Kaley, and P. R. Michael, Monsanto Company, 800 N. Lindbergh Blvd St. Louis, Missouri 63166 Experimental Abstract A method has bean developed lor determining selected Im purities In pentachlorophenol. Chlorodlbenzo-p-dloxlns and chiorodibenzofurans are Isolated from the sample matrix with two-step column chromatographic procedure. Measure ment of these components Is by gas chromatography using electron capture, flume Ionization, or mass spectrometrlc detection. The method can be used as a quality control procedure for monitoring these components at ppb-ppm con centrations In technical pentachlorophenol. ' *' Introduction Pentachlorophenol (PCP) has wide application as a wood preservative and fungicide. Technical grade PCP contains low levels of several impurities, including .chlorodiphenyl ethers (CDPEs), chlorodibenzo-p-dioxiru (CDDs), chiorodibenzo furans (CDFs), and hydroxychlorodiphenyl ethers. Analytical methods for measuring hexa-, hepta- and octa-CDD impuri ties in PCP were recently reviewed ( l) r The authors concluded the method o f Crummett and Stehl (2) provided greatest accuracy and convenience. Newer methods by Pfeiffer (3) and Buser (4) and a revision of (2) by Blaser et al. (5) have also been published. These methods have limitations which preclude their use for routine CDD monitoring o f technical grade PCP. The HPLC method o f Pfeiffer is applicable to highly purified PCP. How ever, it is subject to interference from non-CDD impurities in technical grade PCP. The method described by Buser provides adequate cleanup, but sample pretreatment may lead to positive or negative errors. For example, exposure of technical PCP to strong alkali has been shown to cyclize certain o-hydroxychlorodiphenyl ethers, yielding anomalously high concentrations of CDD (6). Also, petroleum ether does not quantitatively ex tra octa-CDD from alkali solution at the 500-1500 ppm levels typically found in technical PCP. Blaser's method is suitable for determining CDD in techni cal PCP, but it requires use o f GC/MS as the measurement technique. GC/MS is beyond the scope of many laboratories, including most plant quality control laboratories. This paper describes a method which is amenable to routine monitoring of CDDs in technical PCP. CDD components are isolated from PCP by a two-step column chromatographic procedure. The first step removes phenolic components and the second step removes chlorobenzenes, chlorobiphenyfs and CDPEs. The CDD-CDF fraion is analyzed by gas chromato graphy with electron capture, fiame ionization or mass spect romtrie detection. Detection limits depend on the detector and the component being measured. The lower detection limit for 2.3,7,8-tetra-;CDD, which we have not detected in techni cal PCP, is 1 ppb when measured by GC/MS using selected ion monitoring. Reagents 1. Benzene--Pesticide grade. 2. Hexane--Pesticide grade. 3. Methylene Chloride--Pesticide grade. Solutions containing 2 and SOVn (V/V) methylene chloride are prepared by trans ferring 20 and 500 ml methylene chloride to one-liter votu-, metric flasks and diluting to the mark with hexane. 4. Sodium sulfate--anhydrous granular. Analytical Reagent grade. 5. Alumina A. Fisher Adsorption A -540,80-200 mesh. 190 g is heated to 400*C for 4 hours, cooled, and poured into a pint bottle. Ten ml of distilled water is pipetted into the bottle and the bottle capped and shaken at least ten minutes. (The cap should have an aluminum liner.) Absorption o f water by alumina is exothermic, so the bottle will get hot to the touch. Alumina deaivated with 57* water in this manner can be stored on a labora tory shelf for several weeks without deterioration of quality. B. ICN Aluminum Oxide W 200 basic, activity grade Super 1, used as received. 6. Chlorodioxin Standards--as available. We use concentra tions of 0.01 - 0.1 pg/ml tetra-CDD and 1-10 pg/ml of a mixture o f hexa-, hepta- and octa-CDD in benzene. Apparatus 1. Liquid Chromatography Columns A. Macro--30 cm x 1.8 cm i.d. Pyrex with Teflon stopcock. A small amount o f glass wool is placed in the bottom of the column, which is then half filled with benzene. Next, 40 ml o f Fisher deactivated alumina is poured into the column and allowed to settle while tapping the column wail. The alumina is topped with 1 inch o f sodium sul- fate. The stopcock at the bottom of the column is opened and the level o f benzene adjusted to the ton of the packing. Caution: To minimize exposure to benzene, the entire macro-column procedure (column preparation, separation and solvent evaporation) should be carried out in a well-ventilated hood! B. Micro-- 15 cm x 0.5 cm i.d. disposable Pasteur pipette. A small glass wool plug is placed in the bottom o f the pipette and 1.0 g o f dry ICN aluminum oxide is added. The packing is settled by gently tapping 15-20 times with a small spatula (4). 2. Sample Concentrator 500 ml kudema-Danish evaporative concentrator with a 3- ball Snyder column and a 15 ml receiver (Ace Glassware). Further concentration is accomplished with a tnicro- Kudema-Danish concentrator with a 4 ml receiver. 3. Flame Ionization Gas Chromatograph ......... ... A Hewlett-Packard 5731A or equivalent. The column is 3 mm i.d. x 4 m glass packed with 3^ XE-60 or OV-1 on paaw 6 :/ o :/ r ot^-ra iraocos .4 B3 * O) te 0> U 3s AA Ou a U 33 <*b A 3 * O VD 3 3 3 3 33 A 0* A 3 m 'J 0* U M M 3 3 A 3 33 AA h* J O 0 k o. * te A 3 A A A 3 A A LA G G l g nu g y g (j O S g O O O o aa D MMM H fkj - O <0 O O *+ m g * o g g g g 0 O U Uu go o OO O 1- * +j * ** A s M A Q> M u (M K H ui rikih ni ? ? ? ? ? ? ? ? ? ? ? ? ? S " K K ES i 5 5 r-c*<d g IS.Sci* y ** **-> u u S S 5 S *J 4 % S" ^ 5 ^ S ^ $ SN4s0 N*0J tN^ 0ifi n w O iO ifl g ) o te . H K0*_ ? E 5H* h* n IA Eo* ko *' ^o ut* o- yn D ^ U MH ^ I I M M MW i- - oi . n1 nM ni MM OH .o c *-*f \ n c ; w p y *. Hr- M w g p : ;0 81D 5 8 P( O? K Y hn trP * s 5p Eli! t I o. n n -fl . g IA f! 5- s K 45 8 3M n ai i s sI .; a 1 S. * n uoTij*t o r 7) r c cr ^ 9 **ffi 90a> 909 LJ Kl LOJ t O OUOP oC0D VOI o1O*91 CD 9 Ht 9 fft O auV>* (9aaA 0 IA 9au> a LA aW9 9aLn LiAi K* .. s 3s 13g 8 LOJ CD *4 OLOoaa0 s UoO l/i 8UaO * S LOJ g U LOaJ KJ ZWOa m HSU*OO uO *Uo- s M Mil1n/l En IA-* R I-* U* B Enin fe 1 *4 G il B A R i R R R M R 1 Y* O1 ff 85 1 C10 10 w s 5 (0 W i 'S t S V) M "S M a M s# KJ KJ a \ M 4 'S M a 'MS a M a 4 *0 14) 14> a io 8* <s no i M K* Ma \ O n t Ci i *- M KJ oM H C KO 1/1 * H!rt M Y* 7 H M LJ HML*J nH *. i Ci a 1 N KJ MH a M H aa h* K- H J H*v| * B LJ ni K- 1 KJ 1/1 1 a 5 ' [! * sa g? g a2 8' q S 3 "IP O y-se n fc c Ai H p.V. n sL '.l1 DP ujcua yurts r * KXC-ES LOG NUHBER .wc CODE TABLE II ICont'd) sample IDEUTirlCATION MATRIX OATS o r SA LE TANK NUMBER 8ATQ NUM3CR DESCRITTICI! 0T SATIPLE LABEL - . . CACSTIC 8636 9OJ0832 E3-41 3/1/79 8-120 939 2.4 OC? TLnlshad Produce &-03-7009 Tarn 8691 9030833 ES--42 3/11/79 129 C-9 Stili ftaaldua Taa 692 9030834 ES--43 3/11/79 129 C-101 . Stia Pot Char?a - D O Tarn HB693 9030835 ES-44 3/10/79 42 C-101 Torene (aie) 2-4 Dry Traction Yaa 94 9030836 ES-45 3/11/79 ES-46 (Spilcad) ES-47 (CupUcau) 3 C-101 1,4 DC? Cut Yaa KB695 9030837 ES-48 3/12/79 12 C-101 2,4 Tractions (Haavy) Yaa 8696 9030838 ES-49 3/12/79 s ta i C-101 Raaidua Off C-101 2--4 Yaa 8697 9030839 ES-50 (bUb*l*d HS686) Yaa 8698 9031501 3/2/79 IX-03-43 S-l TIalcaa Yaa 8699 9031502 KL-01-06 S-l TlaXaa Yaa 701 9032701 Lot 12302-78 Rhoda PC? -- 3702 9032702 S-L S t a i Sotto Raaidua Yaa 9 704 9042401 ES-52 4/16/79 152 D-LQ Blown l o r Cruda Ho P a-- ^ K a TM S 8706 9042402 9042403 ES-SJ ES-54 4/16/79 4/17/79 2 13 D-10 D-LO Dry Traccioca Cue Phanol CuC So Ko 8707 9042404 ES-S5 4/17/79 11/U D-LO Para-Rieh Cut So 870a 8709 9042405 9042406 ES-56 4/17/79 ES-S7 (Duplici) E s-sa 4/17/79 160 s c ili 0-10 D-10 PC? Product Cut Rasidu Ho HO 8710 % 3711 8712 9042407 9042408 9042409. ES-S9 ES-60 ES-61 4/16/79 4/16/79 4/16/79 Cilar Odor Chlor DC? O d o r r d * DC? rinishad O d o r a Uovo DC7 No Ho HO 3713 714 9042410 9042411 ES-62 4/18/79 ES-63 (Duplici) ES-64 4/19/79 2 12 D-102 2-4-0 RafLnad Aaratad (Stai charca) Tirat Cut - 2,4 - DC? Batch No No 37 IS 9042412 ES-65 4/20/79 2 0-102 1,4-00 Ho 8716 9042413 ES-66 4/19/79 12 D-102 Kifh Bollar Cut Ho 8717 9042414 ES-67 4/19/79 D-102 2,4 Batch Xaaldua No 8721 9050901 ES-63 4/25/79 152 D-19 Stia Cbarga Ho 8722 90*0902 ES-69 4/25/79 Odor D-UO Odor inacor Cruda No 8723 9050903 ES-70 4/25/79 101 0-- 108-110 Aaratad Cruda Ho 0 L # -- * 8725 9050904 9050905 LS-71 ES-72 4/26/79 4/27/79 103 103 D-19 D-19 Dry Tractions Cut Racycla Phanol Ho HO 8726 9050906 ES--73 4/27/79 ia D-19 Farm Rich Cue HO 8727 71 8 729 9050907. 9050900 9050909 ES-74 4/27/79 ES-75 (Duplici) ES--"6 4/27/79 ES--77 (Duplici ES-" 160 S tili D-19 D-19 . Parmetdorophano1 Raaidua Ralahlad 8541 Ho HO 8730 9050910 ES-79 C-6-124 S-L Tlaka -- 8 736 9051701 ES-30 5/7/79 101 -- Traah PC? No 8737 9051702 E3-J1 3/7/79 351 lUactor aaa No 8738 9051703 ES-82 5/7/79 10 S-l PC? Cut Ha 8739 87*0 741 9051704 9051705 9051706 ES-93 5/7/79 CS--90 (Duplici! ES-44 5/7/11 (ne) ES-35 (Duplica) CS-36 5/7/79 10 10 10 S-l Intar^adla Cut 1-1 Santophan Cut 1-1 Laac Traction . Ho Ho Ho 8 742 9031707 ES-37 5/7/79 IO S-l Raaidua Stia Raaidua Ho i li V s 9 >3 ."3541* 200 S U r filV S * ^ \ * 6 5 J* 7100 5100 pA K U tu * * ^ 654* 654* 654* "3 6 5 4 654 9600 6100 va 000 11000 ,0655 MD<50 656 SD<50 657 mxso esa KIXSO 659 B90 1 (U U iM ^ 660 661 601 KD<50 180000 180000- 661 1B00 l 6 6 J (l* c X=J 64000 * ( la d Lxc) 4500 664 KD<J0 * 665 4 JO 666 HDOO XBs 10X30 663 <10 669 669 SDOO <10 670 ISO 671 671 671 11000 10000 8500 6 7 2 ( l i t l i t ) 180000 RgVt*'*'" (2nd 11000 673 73 674 74 6 7S 75 676 52 677 677 677 SD<JO SD<J0 ND<J0 fc/6* 67B R # * --- 679 pMUtrtCtC-* ^ 6 3 0 631 ancP-*^ 633 2HbLP'ur * J 2000 2(0000 12000 3400 9500 Tjjle ri: pC0/% , . . .. F r 0ter-'I,U3/.Q, , CSlorsonnol md ?intaahn - ?7?e>* ijnal *** O ^ c t ----- -- 50 9800 8600 10000 8100 7000 7000 5100 5600 KD< 20 ND<20 <23 <20 . 180 to x io 91000 79000 970 59000 5600 130 SD<30 ND<30 KD<30 KD<10 SD<30 39 100 2600 2000 22CO 200C00 6400 7 03 65 ND<30 1D< 10 55 67 5400 190000 7800 24000 29000 CI3 ND<20 2000 18 CO 3300 3100 2100 3B00 NIX30 SD<30 SIX 30 SIX30 45 SD<J0 11000 12000 180 15000 2400 81 SIX20 SIX 23 S0<20 <20 KD<20 28 SD<20 160 140 300 35COO 2300 66 55 39 NIX20 ND<20 XD<I0 58 1400 64030 2700 13000 13000 C l4 SDOO 65 35 70 130 100 110 UO 100 SIX 10 SEX10 KIX10 SD<10 SIX LO tax la 180 270 SIX 10 3100 250 tax la StXL SIX 10 SIX 10 stx io ta x io SD<10 SExLO SD<10 SD< 10 KXS 5900 240 SIX 10 HIX10 SIX 10 SIX 10 ' KIX10 XIX10 :a x l0 21 6200 69 340 190 C i5 SIX 200 ta x 50 tax so -- ND*SO NIX 50 NCXSO ta x 20 ND<50 six sa SD<SO 10X50 ta x so SD<50 10x50 tax so NEK50 6700 170 ta x 20 ta x 20 s i x 20 XIX IO HD<20 XTX20 SD<!0 10X20 ta x 20 tax so ND<40 1900 220 ta x 2o XD*20 10X20 10X20 SD<20 10X20 SD<20 SD< 20 100 S0<20 XD< 20 S0<20 C16 NIX700 SD<50 XIX50 tax so ta x so la x s o * 10X50 NO<40 KIX40 NIX40 10X40 ta x 40 ta x 40 ta x 40 XD<40 ta x 40 ta x 40 NEX4Q 1300 350 HD<40 ta x 40 SIX 40 XD<40 SIX 40 ta x 40 10X40 10X40 ND*40 ND<40 XIXi o 5200 220 NIX40 ta x 40 ta x 40 ND4 40 ND<40 XD< 40 :id<40 XD< 40 450 NIX 40 ta x 40 SD<40 C17 5000 tax so SIX s o -- XD<50 10X50 -- MIX20 MIX40 ta x 20 ND<20 XD<20 KX20 tax 20 NIX20 ta x 20 tax io ta x 20 2200 lia MX40 ta x 40 XIX40 ND<40 NIX40 SIX 40 10X40 KX40 SD<40 SD<40 tax 20 1300 ND<40 tax40 SIX 40 SD<40 tax 40 ND<40 SD< 40 SD* 40 tax jo 2B0 SD< 40 SD<40 SIX 40 C3, - , SD<3000 SC<50 SIX 50 SD<50 m xso ^ 50X50 10X50 KD<30 ND<30 stxJO SD<30 ta x 30 SDoa SIX 30 SIX 30 SDOO ta x 30 ta x ja 440 37 ta x Jo 10X30 SIX 30 NIX 30 SD<30 ta x 30 SD<30 ND<30 ND<30 SD<30 SIX 20 160 1IDOO tfiXJO ta x 30 SD<30 KD*30 SIX 30 SD<JO SD<JO ND<JO 140 ND<J0 SD<JO X SDOO ^ >x - 12 - F* U V * - . TABLE IV PPB Levels of TCDD In Selected Samples (MIC-ES Sample (Replicate) L m b 653 (Replicate) W a /V-^MB654 LSS (Replicate) (Replicate) - C K (Replicate) s -* MB698 5 />i* --- a701 ^ t b o S - -- MB702 J 2 & ? t b t / & - -- MB709 iuapfr -- " 715 -- 118717 3 7 fZfcifct* _MB741 Eastman PCP Lab 2,4-DCP (unknown source) 1,3,6,8TCDD et-al65 35 70 - 110 88 110 47 85 20 33 ND<20 170 2200 ND<20 7500 25 ND<20 ND<20 2,3,7,8 TCDD ND<20 ND<20 ND<20 23 25 ND<60 180 240 ND<10 ND<10 ND<20 ND<150 190 ND<20 660 ND<20 ND<20 HD<20 12 TABLE IV PPB Levels of TCDD in Selected SamDles (MIC-ES) Sample MB6S3 MB653 (Replicate) MB653 (Replicate) MB654 MB654 (Replicate) MB654 (Replicate) MB697 MB697 (Replicate) MB698 MB699 MB701 MB702 MB709 MB71S MB717 MB741 . Eastman PCP Lab 2,4-DCP(unknown source) 1 ,3,6,8TCDD et. al. 65 35 70 - 110 88 no 47 85 '20 33 ND<20 !170 2200 ND<20 7500 25 ND<20 ND<20 2,3,7,8. TCDD ND<20 ND<20 ND<20 23 25 ND<60 180 240 ND<10 ND<10 ND<20 ND<150 190 ND< 20 660 ND<20 ND<20 ND<20 12 TABLE IV PPB Levels of TCDD in Selected Samples (MIC-ES) Sample MB653 MB653 (Replicate) MB653 (Replicate) MB654 MB654 (Replicate) MB654 (Replicate) MB697 MB6 9 7 (Replicate) MB698 MB699 MB701 ' MB702 MB709 MB715 MB717 MB741 Eastman PCP o /._n/"o ta //'ss ,, 1,3,6,8TCDD et, al. 2,3,7,8 TCDD 65 ND<20 35 ND<20 70 ND<20 110 88 110 23 25 ND<60 47 180 85 240 20 ND< 10 33 ND<10 ND<20 ND<20 170 ND<150 2200 190 ND< 20 ND< 20 7500 660 25 ( t ir it i L4 I r " i 55^ I*??