United States Environmental Protection Agency Environmental Monitoring Systems Laboratory Las Vegas NV 89114 Research and Development EPA/600/S4-86/021 July 1986 Project Summary Performance of RCRA Method 8280 for the Analysis of Dibenzo-p-Dioxins and Dibenzofurans in Hazardous Waste Samples J. M. Ballard, T. L. Vonnahme, N. J. Nunn, D. R. Youngman, and Stephen Billets Further evaluation of RCRA Method 8280 for the analysis of chlorinated dibenzo-p-dioxins and dibenzof urans, has been performed. The Method has been modified to enable the quantitation of total tetra- through octa-chlorinated dibenzo-p- dioxins and dibenzofurans, and has been applied to six different sample matrices derived from industrial polychlorophenol sources and also from fly-ash, still-bottom, and Missouri soil samples. An interlabora- tory validation of the Method has been conducted in two phases: Phase I required the analysis of spiked and unspiked clay and sludge samples for certain specified analytes, and Phase II required the analysis of 10 samples of soil, sludge, fly-ash and still-bottom for total tetra- through octa- chlorinated dioxins and dibenzofurans. Method detection limits of 13 C12-labeled polychlorinated dioxins and dibenzofurans in seven matrices have been determined. In addition, a comparison was made of the Contract Laboratory Program carbon col- umn cleanup (without backflush) with the corresponding backflush procedure used in the proposed RCRA Method. This Project Summary was developed by EPA's Environmental Monitoring Sys- tems Laboratory, Las Vegas, NV, to an- nounce key findings of the research pro- ject that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction On a molecular basis, 2,3,7,8-tetrachlor- odibenzo-p-dioxin (2,3,7,8-TCDD) is one of the most poisonous synthetic chemicals known. The compound has been shown in animals to possess teratogenic, embryo- toxic, carcinogenic, and co-carcinogenic properties in addition to acute toxicity. Because of its chemical stability, lipophilic character, and extreme toxicity, it presents potentially severe health hazards to the human population. Although 2,3,7,8-TCDD is the most toxic of the 75 chlorinated dibenzo-p-dioxins (PCDD's), many of the others (and also of the 135 chlorinated dibenzofurans [PCDF's] which have similar genesis, structures, and properties) are known to possess relatively high toxicity to humans and animals. For this reason, the entire class of PCDD's and PCDF's is of environmental concern. The first synthesis of 2,3,7,8-TCDD was reported in 1872, and only sporadic re- ports of the preparation of PCDD's, con- taining two, four, or eight chlorine atoms, appeared in the literature during the years 1941-1965. Particular interest in 2,3,7,8- TCDD, and in the PCDD's and PCDF's in general, increased markedly with the dis- covery in the early 1970's of the same ter- atogenic and toxic effects with certain commonly used herbicides, e.g., 2,4,5-tri- chlorophenoxyacetic acid (2,4,5-T), as were observed with 2,3,7,8-TCDD. Analysis of 116 samples of 11 different pesticides ------- produced during the period 1950-1970 re- vealed the presence of PCDD contamina- tion (tetra- through octa-chlorinated) in 42 percent of the samples. Consideration of the chemistry of pesticide manufacture in- dicated that PCDD's could be formed in competing side-reactions of the polychlor- ophenol precursors. The domestic use of 2,4,5-T was subsequently banned, and the military use of Agent Orange (1:1 mixture of 2,4,5-T and 2,4-dichlorophenoxyacetic acid) as a defoliant in Vietnam was discon- tinued, both in the early 1970's. Because of the widespread usage of pesticides potentially contaminated with PCDD's, a Dioxin Monitoring Program was set up by the EPA in 1973 to develop an analytical method capable of detecting 2,3,7,8-TCDD in environmental samples at the part per trillion (ppt) level. This effort formed the basis of the National Dioxin Strategy of the Agency. Although the most ubiquitous routes of non-occupational exposure of the general population to dioxins have probably been via the use of contaminated pesticides and from the emissions of municipal waste in- cinerators, the most concentrated waste sources of 2,3,7,8-TCDD are the tars and sludges resulting from the commercial pre- paration of 2,4,5-trichlorophenol (2,4,5- TCP). This latter fact was highlighted dur- ing an investigation in 1975-1977 of unex- plained animal deaths at various horse arenas in Missouri. It was discovered that the sites had been sprayed with a mixture of waste oil and distillation residues from the manufacture of 2,4,5-TCP which were contaminated with 2,3,7,8-TCDD. Subse- quent investigation of chemical waste dump-sites in New York State (Hyde Park; love Canal), where wastes from the man- ufacture of 2,4,5-TCP had been buried, also revealed the presence of substantial amounts of 2,3,7,8-TCDD. As a result of this experience, it was concluded by the EPA that samples con- taining tetra-, penta-, and hexa-CDD's and CDF's are likely to exhibit increased toxi- city (40 CFR 261:1978, January 14, 1985), and a method to analyze hazardous wastes for the relevant PCDD's and PCDF's was included in the Resource Conservation and Recovery Act (RCRA) requirements for hazardous waste monitoring as published in the Federal Register (40 CFR 65:14514, April 4, 1983). A single-laboratory evalua- tion of the RCRA Method 8280 for the analysis of PCDD's and PCDF's in hazar- dous waste has been the subject of a pre- vious report prepared for the Office of Solid Waste (EPA-600/4-85/082). That report presented results obtained with sample matrices including pottery clay, a Missouri soil, a fly-ash, a still-bottom from a chlorophenol-based herbicide production process, and an industrial process sludge. Major revisions to the Method as first published in 1983 were necessary to ac- commodate the analysis of complex sam- ples such as sludge and still-bottom. The revised Method 8280 has subse- quently undergone a period of continual development, and this summary presents results obtained during the further evolu- tion of the Method. Study Design Changes made to the proposed Method since publication of the previous report are summarized as follows: in order to improve the accuracy of quantitation of the hepta- and octa-CDD's and CDF's, a second in- ternal standard (13C12-OCDD) is added to- gether with 13Cl2-2,3,7,8-TCDD prior to sample workup. Some of the ions specified in the multiple ion detection (MID) descrip- tors have been changed so as to increase sensitivity by monitoring the most intense ion in the isotopic cluster. To ensure that co-eluting polychlorinated diphenyl ethers (PCDE's) are not contributing to the signal response due to PCDF's, the molecular ion of the appropriate PCDE was included in each MID descriptor. In addition, the cri- teria for the positive identification of PCDD and PCDF isomers were made more ex- plicit. Instrument tune criteria employing perfluorotri-/7-butylamine (FC-43) were substituted for those based on the use of decafluorotriphenylphosphine (DFTPP). The section on the calculation of concen- trations of analytes was expanded to in- clude a procedure for measuring unknown PCDD and PCDF isomers. The performance of the Method was in- itially examined by its application to the analysis of a variety of wastes derived from the use of polychlorophenols in the wood-preserving industry. As an additional test of Method performance, an interlab- oratory validation study was conducted in two parts. A two-part study was used be- cause the Method had been extensively improved since its publication in the Federal Register, and it was felt that par- ticipating laboratories would be unfamiliar with some of the revised procedures. The first phase was intended to allow the par- ticipants to acquire familiarization with the Method by analyzing relatively simple mat- rices for a few specified analytes which had been spiked into the samples. The se- cond phase required the total quantitation of tetra- through octa-CDD's and CDF's in complex samples containing the analytes at both low and extremely high levels; no spiking was used for these samples. A method detection limit study using a available 13C12-labeled PCDD and PCD isomers spiked into seven different sarr pie matrices was also performed. A corr parison of the EPA Contract Laborator Program (CLP) carbon column cleanu] without and with a backflush elution pro cedure was conducted to test the ade quacy of the CLP method for the deter mination of total PCDD's and PCDF's. Results The single-laboratory application of thi Method to the determination of PCDD': and PCDF's in complex environmenta samples (e.g., fly-ash, still-bottom, am wastes from the industrial use of penta and tri-chlorophenol) has routinely yield ed excellent recoveries (60 to 85 percent of the spiked internal standard 13Cl2-2,3 7,8-TCDD (see Tables 1 and 2). This indi cates that the extraction and cleanup pro cedures are able to accommodate sample! ranging from those with a high aqueous content to viscous oils and chemical slud ges. It can be assumed that endogenous PCDD's and PCDF's are extracted witr equal success if matrix effects are not ir effect. In the absence of a full range of stan dard reference materials, the accuracy o the Method is rather difficult to assess However, data obtained from Phase I o the interlaboratory study indicate that the Method is biased high and that the bia: appears to decrease as the concentrations of the analytes increase (see Table 3). Date from the method detection limit (MDL study can be used as an indicator of intra laboratory precision. For seven replicate determinations of a TCDF and a PeCDD ir fly-ash, with each at a measured concen tration of 2.6 times their final calculatec MDL's, the relative standard deviations (RSD's) were 12.3 percent and 12.2 per- cent, respectively. Similar determinations for a PeCDF and a TCDD which were mea- sured at a level 6.0 and 4.4 times their MDL's gave RSD's of 5.2 percent and 7.2 percent, respectively. Encouraging results were obtained from Phase I of the interlaboratory study in which specific analytes spiked into clay and sludge samples were quantitated. The mean value for 114 determinations of 11 analytes spiked into clay at the 5 ppb level was 6.02 ± 2.78 ppb. The mean value for 16 determinations of two analytes spiked into clay at the 2.5 ppb level was 3.56 ± 2.35 ppb. The mean value for 57 determinations of six analytes spiked into sludge at the 125 ppb level was 126.4 ± 57.9 ppb. The good overall recovery (greater than ------- Table 1. Analysis3 of POP Process Samples Using Method 8280 PCCD/ PCDF TCDD PeCDD HxCDD HpCDD OCDD TCDF PeCDF HxCDF HpCDF OCDF 13r °72" 2,3,7,8- TCDD per- cent recovery Sludge B-6d (ppb) /VDb ND 2150 51520° 72300° ND ND 68 343 4100° 66.8 Fuel oil B-7b (ppb) ND ND 2186 67176° 154000° ND 154 2933 1342 7500° 69.0 Sludge B-8b (ppb) ND ND ND 2166° 2670° ND ND ND ND ND 64.3 Sludge B-12h (ppb) ND ND ND 978° 2550° ND ND ND ND 76 67.8 Fuel oil A-2g (ppb) ND ND 2079 38195° 59100° ND 246 2852 1913 447 69.2 Alcohol fuel oil A-3g (ppb) ND ND 762 17956° 24500° ND ND 76 1118 741 60.0 Sludge A-4g (ppb) ND ND 726 59600° 106000° ND ND 1568 1948 3200° 62.9 Soil A-5g (ppb) ND ND 283 12945° 16500° ND ND 65 533 900° 77.0 Soil A-6.1g (ppb) ND 27 730 24700° 26300° ND 61 252 1695 3080° 75.4 Soil A-6.2g (ppb) ND ND 396 12300° 15000° ND ND 56 434 1690° 74.8 aMean of duplicates; concentrations shown are for the total of all isomers within a given homologous series. bND is below detection limit for the sample matrix. Detection limits are estimated as 5 ppb for the tetra- through hexa-isomers and as 10 ppb for the hepta- and octa-isomers. 0 Due to the extremely high levels of HpCDD, OCDD, and OCDF detected in the GC/MS analysis, the extracts were diluted after normal quan- t/tat/on of the tetra-, penta-, hexa-CDD/CDF and hepta-CDF. HpCDD, OCDD, and OCDF were then quantitated versus 13C12-1,2,3,4-TCDD which was added after dilution; the values are corrected for 13C12-2>3,7,8-TCDD recovery. Table 2. PCCD/ PCDF TCDD PeCDD HxCDD HpCDD OCDD TCDF PeCDF HxCDF HpCDF OCDF 13r °/2~ 2,3,7,8- TCDD percent recovery Analysis3 of PCP Process Sample (B-5) and 10 TCP Process Samples Using Method Water B-5 (ppb) /VD6 ND 0.072 2.5C 1.25° 0.024 ND 0.017 0.136 0.029 67.3 Sawdust H-3 (ppb) ND 385 268C? 2314° 1250° 3593d 1903d 11903d 1374d 94° 95.2s Soil H-7a (ppb) ND ND ND ND 5.5 ND ND ND ND ND 71.2 Soil H-7b (ppb) ND ND ND ND ND ND ND ND ND ND 76.4 Soil H-7c (ppb) ND ND ND ND ND ND ND ND ND ND 72.3 Water 1-1 (ppb) ND ND 11Cf 1677° 345° 3.9* ND 233d 108° 16° __f Sludge 1-2 (ppbl ND 30 241 O* 42134° 14658° 207 429 5496d 2768° 239° 77.1 8280 Sludge 1-11 (ppb) ND ND 399 4404° 4080° 68 23 626 622° 151° 75.6 Soil 1-1 2c (ppbl ND ND ND ND ND ND ND ND ND ND 84.9 Soil l-14a (ppb) ND ND ND 37 20 ND ND ND ND ND 78.7 So/7 l-14b (ppb) ND ND ND ND ND ND ND ND ND ND 84.1 aMean of duplicates except for samples B-5 and 1-1 which are the result of single determinations. Concentrations shown are for the total of all isomers within a given homologous series. bND is below detection limit for the sample matrix. Detection limits are 5 ppb for soil, sawdust, sludge, and are 0.01 ppb for water. °'dDue to the very high levels of some hexa-, hepta-, or octa-CDD/CDF isomers, some samples were diluted, and the PCDD's and PCDF's noted were quantified versus '3C12-OCDD° or '3C12-1,2,3,4-TCDDd; the values are corrected for 13C12-2,3,7,8-TCDD recovery. eSome interference at the quantitation ion was noted. Gross interference at the quantitation ion was noted. ------- Table 3. Interlaboratory Test of Method 8280, Phase I: Accuracy and Bias of Results Sample Spike Level Number of Accuracy Type (ppb) Determinations (Percent) Bias (Percent) ± SO of Bias Estimate Clay Clay Sludge 2.5 5.0 J25 16 114 57 142.4 120.4 101.1 + 42.4 + 20.4 + 1.12 ± 11.8 ± 5.27 ± 6.14 50 percent) of the internal standard and the small differences between the spiked concentrations and the mean measured values both indicate that the Method can provide acceptable data in a multilabora- tory program. Phase II of the interlabora- tory study which required the quantitation of total tetra- through octa-CDD's and CDF's in 10 aliquots of 4 sample types, also provided satisfactory results. The in- ternal standards (13Cl2-2,3,7,8-TCDD and 13C12-OCDD) were recovered in overall ac- ceptable yields ranging from 51 to 82 per- cent. However, quantitation of the analy- tes was less precise than in Phase I. Two major, probable reasons for this are as follows: 1. The complex samples themselves which sometimes contained endog- enous amounts of the target analytes at low and at extremely high levels; this led to a large dilution requirement which eliminated the value of the iso- topic dilution method of quantitation. 2. The need for an analysis which re- quired the identification, confirma- tion, and quantitation of an unknown number of peaks for each congener often without an authentic reference standard which could be used to confirm the identification of each congener. In general, the Method performed well when the laboratories followed the pro- tocol. A visual examination of the data showed that approximately 85 percent of the values reported by the 5 laboratories and used in the statistical analysis were consistent among the laboratories. Statistical analysis of the Phase II data revealed that: • Recovery of 13Cl2-2,3,7,8-TCDD in- ternal standard was a function of sample type, whereas that of 13C12 -OCDD internal standard was not. • The laboratories were equivalent in accuracy for all analytes except OCDD. • The laboratories were equivalent in precision for 31 of the 40 possible matrix/analyte combinations. Method detection limits of eight 13C12 -labeled PCDD's and PCDF's spiked into reagent water were found to be in the low ppt range (less than 10 ppt); 42 of 48 val- ues determined for 6 environmental sam- ples were less than 5 ppb (see Table 4). Several characteristics and trends are apparent in the data: 13C12-2,3,7,8-TCDD/ TCDF usually had the lowest MDL values for each sample type, while 13Cl2-HpCDD/ OCDD usually had the highest; as might be expected, the MDL values for all analytes generally increased in passing from the "clean" sample types (reagent water, fly-ash) to the more complex, organics-containing matrices (still-bottom, industrial sludge). The MDL for 13C12- 2,3,7,8-TCDD in reagent water (0.44 ppt) determined in this study using Method 8280 compares well with the value re- ported for 2,3,7,8-TCDD in reagent water Table 4. Method Detection Limits of '3C,2-Labeled PCDD's and PCDF's in Reagent Water (PPT) and Environmental Samples (PPB) (2 ppt) and determined using Method 61 (capillary column GC/MS with selected io monitoring). An experimental comparison of th Contract Laboratory Program (CLP) carbo column cleanup (the backflush procedur is not used) with the backflush procedur used in Method 8280 was undertaken be cause the CLP method should be faste and should consume much less solven while it does not require HPLC equipment Twin open carbon columns were spikei with a standard solution containing a mix ture of 11 PCDD's and PCDF's. The firs column was eluted with a 2-mL and < 5-mL aliquot of toluene; the second co lumn was eluted similarly in the reverse flow direction. The four fractions wer< analyzed separately, and the recoveries (see Table 5) indicated that although the CLP cleanup as written is very satisfactory for the determination of 2,3,7,8-TCDC (and possibly other tetra- and penta-CDD's and CDF's) it is not adequate for the deter mination of hexa-, hepta-, and octa-CDD's and CDF's. However, the combination o1 an open carbon column with a backflusr procedure gave an acceptable perform ance for the tetra- through octa-substi tuted congeners. Recommendations As a result of the experience gained dur- ing the single- and multi-laboratory testing of the Method with a variety of environ- mental samples, several modifications to the Method and areas of further study are recommended: 1. The Method should allow for the use of disposable, open carbon col- umns as an option to the currently specified HPLC carbon column cleanup. This would allow for an in- crease in the rate of sample through put and would also reduce solvent consumption. 13C12-Labeled Analyte 2,3,7,8-TCDD 1,2,3,7,8-PeCDD 1, 2,3,6,7, 8-HxCDD 1,2,3,4,6, 7,8-HpCDD OCDD 2,3,7,8-TCDF 1,2,3,7,8-PeCDF 1,2,3,4,7,8-HxCDF Reagent Water3 0.44 2.35 6.63 5.45 7.37 0.58 1.50 2.53 Missouri So//6 0. 13 0.70 1.24 1.60 1.35 0.11 0.33 0.83 Fly- Ash" 0.07 0.25 0.55 1.41 2.27 0.06 0.06 0.30 Industrial Sludge0 0.40 1.47 2.26 3.39 7.68 0.36 0.58 1. 15 Still- Bottomd 1.81 2.46 16.2 4.59 10.1 2.26 1.61 2.27 Fuel Oif 0.75 2.09 5.02 8.14 23.2 0.48 0.80 2.09 Fuel Oil/ Sawdust* 0.13 0.18 0.25 0.49 1.34 0.04 0.09 0. 17 a Sample size 1,000 mL b Sample size 10 g. c Sample size 2 g. ° 'Sample size 1 g. Note: The final sample-extract volume was 100 for all samples. ------- Table 5. Percent Recovery3 of PCDD's and PCDF's from CLP Carbon Column Method as Written (without Backflush) Analyte 2,3,7,8-TCDF 1,2,3,4-TCDD 2,3,7,8-rCDD 1,2,3,7,8-PeCDF 1,2,3,4,7-PeCDD 1, 2,3,4,7, 8-HxCDF 1, 2,3,4,7, 8-HxCDD 1,2,3,4,6,7,8-HpCDF 1,2, 3,4,6,7, 8-HpCDD 1, 2,3,4,6,7, 8,9-OCDD 1, 2,3,4,6,7,8, 9-OCDF 2 mL Toluene Fraction 81.5 80.0 87.6 71.0 80.9 35.9 39.6 7.8 13.4 ND ND Additional 5 mL Toluene Fraction ND ND ND 14.0 ND 43.0 46.0 52.6 62.0 50.8 36.0 Total 81.5 80.0 87.6 85.0 80.9 78.9 85.6 60.4 75.4 50.8 36.0 Method Modified (with Backflush) 2 mL Toluene Fraction 83.0 80.3 87.6 85.4 87.5 74.5 80.3 54.4 57.8 48.2 45.7 Additional 5 mL Toluene Fraction ND ND ND ND ND 9.8 9.8 25.5 22.6 25.8 26.9 Total 83.0 80.3 87.6 85.4 87.5 84.3 90.1 79.9 80.4 74.0 72.6 aResults of a single determination. ND = Not detected. 2. The use of stacked acidic/basic silica gel columns instead of multi- ple liquid-liquid partitioning in the extraction/cleanup procedures should be investigated. This would eliminate the problems of emulsion formation currently encountered and would also greatly reduce the quantities of corrosive wastes generated. 3. Gas chromatography (GC) condi- tions should be modified to improve the resolution between the internal standard (13C12-2,3,7,8-TCDD) and the recovery standard 13C12-1,2,3,4- TCDD). If this cannot be readily achieved, then use of an alternative recovery standard should be considered. 4. The elution windows (defined by first and last eluting isomers) of the tetra- through octa-CDD and CDF congeners should be established for the GC conditions used in the Method. 5. Because of the known elution over- lap of some tetra-substituted iso- mers with penta-substituted iso- mers (and other potential overlaps between homologous groups), the multiple ion detection (MID) de- scriptors should be modified to in- clude at least one ion for each overlapping homologue. 6. Method 8280 should be written to require as many GC/MS analyses as necessary by using the appropriate MID descriptors whenever an elu- tion overlap is noted in a sample. 7. Kovats Indices should be deter- mined for available PCDD's and PCDF's. This would aid laboratories 10. in the identification of isomers not known or available to them and would be useful in a GC screening program. The need to monitor for polychlorin- ated diphenyl ethers (PCDE's) in the final sample extract should be investigated. A source of a well-defined GC per- formance standard should be iden- tified. Column performance guide- lines should be established for a variety of columns. Sample reanalysis requirements giv- en the presence of low and of very high levels of target analytes should be defined. ftU.S.Government Printing Office: 1986 — 646-116/40618 5 ------- J. M. Ballard, T. L. Vonnahme, N. J. Nunn, andD. R. Youngmanare with Lockheed Engineering and Management Services Company. Inc.. Las Vegas, NV 89114. Stephen Billets is the EPA Protect Officer (see below). The complete report, entitled "Performance of RCRA Method 8280 for the Analysis of Dibenzo-p-Dioxins and Dibenzofurans in Hazardous Waste Samples, "(Order No. PB 86-193 679/AS; Cost: $11.95, subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA2216J Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Environmental Monitoring Systems Laboratory U.S. Environmental Protection Agency P.O. Box 15027 Las Vegas. NV 89114 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 ^F7>, US.OFFiC!A..i •••".. " ----" -- _/ * ^ j ., V* i w « ™ | * Official Business Penalty for Private Use $300 EPA/600/S4-86/021 0000329 PS U S ENVIR PROTECTION AGENCY REGION 5 LIBRARY 230 S DEARBORN STREET CHICAGO IL 60604 ------- |