Introduction to Dioxins/PCBs

1. Introduction to Dioxins/PCBs Presented by Chris Cornwell

2. Purpose • To provide general information on Dioxins/PCBs. • To define terms related to Dioxins/PCBs. • To describe the analytical methods. • To describe uncommon terms. • Example Reports • To answer your questions.

3. What are dioxins?

4. What are Dioxins? Dioxins are a group of chlorinated chemical compounds based on two unique molecules. • The dibenzodioxin nucleus 2. The dibenzofuran nucleus The term “dioxins” can be used to mean both sets of compounds.

5. What are Dioxins? • Remember, “Dioxins” is often used to describe a group of 210 polychlorinated dibenzo-p-dioxin and dibenzofuran congeners (PCDD/Fs). • 17 dioxins are distinguished as a sub-group, each of which is characterized by at least four chlorine atoms in the 2,3,7,8 positions. They are commonly referred to as “the seventeen 2,3,7,8-substituted PCDD/F congeners” and the “named peaks”. These are considered to be the most toxic. They are the ones whose toxicity is defined. • All the other dioxins belong to the Totals. Totals come in many varieties.

6. What are Dioxins? Dibenzodioxin Eight Substitution Positions 75 Mono-Octa Dioxin Congeners 49 Tetra-Octa Dioxin Congeners Dibenzofuran Eight Substitution Positions 135 Mono-Octa Furan Congeners 87 Tetra-Octa Furan Congeners 210 Mono-Octa Total Congeners 136 Tetra-Octa Total Congeners

7. What are Dioxins? If a Dioxin (or Furan) has at least the 2, 3, 7, and 8 positions filled. 2,3,7,8- Toxic Substitution Positions 9 1 O 8 2 7 3 O 6 4

8. What are Dioxins? • 2,3,7,8-TCDD • 1,2,3,7,8-PeCDD • 1,2,3,4,7,8-HxCDD • 1,2,3,6,7,8-HxCDD • 1,2,3,7,8,9-HxCDD • 1,2,3,4,6,7,8-HpCDD • OCDD • 2,3,7,8-TCDF • 1,2,3,7,8-PeCDF • 2,3,4,7,8-PeCDF • 1,2,3,4,7,8-HxCDF • 1,2,3,6,7,8-HxCDF • 1,2,3,7,8,9-HxCDF • 2,3,4,6,7,8-HxCDF • 1,2,3,4,6,7,8-HpCDF • 1,2,3,4,7,8,9-HpCDF • OCDF The Seventeen Toxic Congeners

9. The dioxin problem

10. The Dioxin Problem • First observed in connection with the teratogenic effects found in 2,4,5-Trichlorophenoxyacetic acid (2,4,5-T) in 1957. • 2,3,7,8-TCDD or PCDD/F impurities in Hexachlorophene Pentachlorophenol PCBs

11. The Dioxin Problem Industrial Accidents 1949 Monsanto (USA) 1953 BASF (Germany) 1963 Philips-Duphar (Netherlands) 1966 Rhone-Poulenc (France) 1968 Coalite & Chemicals Products (UK) 1976 ICMESA (Seveso, Italy)

12. The Dioxin Problem • 1960’s: Operation Ranch Hand (Vietnam) • 1968: Yusho Cooking/PCB Oil (Japan) • 1971: Times Beach (USA!!) • 1977: Waste Combustion (Netherlands) • 1985: Bleaching Pulp (USA) • 2004: President Viktor Yushchenko (Ukraine) • 2008: Naples Mozzarella and Irish Pork Crisis' • 2011: German Feed Crisis (pork and poultry)

13. Methods

14. Dioxin Methods Several analytical protocols are currently available for measuring PCDD/Fs. • Each of the main USEPA environmental statute (i.e., CAA, CWA, SDWA, RCRA) that regulates “dioxins” specifies a particular methodology. Method 23 is designed to support the CAA for the measurement of PCDD/Fs in stationary source of emissions. Method 8290 is required for RCRA and CERCLA (Superfund) activities. Method 1613 is required for CWA and SDWA compliances (e.g., NPDES permits, DLM). Method TO-9A supports air quality.

15. Dioxin Methods • Simply put, the methods are equivalent. They measure the same compounds -- the 17 2,3,7,8-substituted PCDD/F congeners, the “total homologue” groups for the tetra- through octa-chlorinated PCDD/F congeners -- using the same technology They provide very similar performance characteristics (i.e., precision, accuracy, reliability, detection limits). They call for the use high-resolution gas chromatography and high-resolution mass spectrometry (HRGC-HRMS). They call for the use isotope-dilution. Samples are fortified with a collection of labeled PCDD/F congeners (e.g., 13C12-1,2,3,7,8-PeCDF) before the extraction, before the sample fractionation (cleanup), and before the analysis by HRGC-HRMS. The role of these labeled compounds is to monitor sample preparation efficiencies as well as to characterize both qualitatively and quantitatively the 2,3,7,8-substituted congeners, and the total homologue groups.

16. PCB Congener Method One method dominates the PCB congener market. Method 1668 is required for Clean Water Act (CWA) programs (e.g., NPDES permits, TMDL studies, CBC). • Versions A, B*, and C exist. Versions A and C are very similar and of primary concern. Existing studies use version A. C has tighter QA/QC limits, causing about 5-20% more failures, which may be more representative of the data in a method measuring so many parameters at once. • The USGS, NOAA, WHO, DRBC, and many other lists exist. CFA offers quantification of all 209 congeners. * Version B was largely ignored by laboratory and regulators due to disagreements over QA/QC requirements, too loose in some areas, too tight in others.

17. Isotope dilution

18. Isotope Dilution What do we do with the 13C labeled congeners? (PCBs and Dioxins) Act as surrogates and internal standards for the native congeners at each step in the preparation and analysis: • Extraction Standards(ES) just before the extraction. • Cleanup Standards (CS) just before the fractionation. • Injection Standards (JS) just before the injection.

19. Isotope Dilution Extraction Standards (ES) When? Extraction Standards are introduced inside the sample matrix before the extraction step. Why? • Used to measure the overall extraction and fractionation efficiency • Used in the qualitative and quantitative characterizations of native dioxins Note: Methods 23 and 8290 name them Internal Standards while Method 1613 uses the Labeled Compounds

20. Isotope Dilution Cleanup Standards (CS) When? Cleanup Standards are introduced to the sample after extraction but prior to the cleanup step (when applicable.) Why? • Used to measure the efficiency associated with the fractionation step alone. Method 1613 names the only compound used as the Cleanup Standard.

21. Isotope Dilution Injection Standards (JS) When? • Injection Standards are introduced to the sample after cleanup but prior to injection. Why? • They act as internal standards to determine the recoveries of the Extraction and Cleanup Standards. • Provide a measurement of injection efficiency useful to the analyst. Methods 23 and 8290 name them Recovery Standards while Method 1613 calls them Internal Standards.

22. High resolution mass spectrometry

23. High Resolution Mass Spectrometry How high is high? Well, it’s 10000 Resolving Power! The ability to zoom in on a mass spectrum and tell the differences between masses that are very close in weight. The Origin of the 10,000 Resolving Power Requirement: The need for high-resolution mass spectrometry for the analysis of TCDD was recognized early in 1970 by Baughman and Meselson while studying dioxin-contaminated fish samples from South-East Asia. The presence of large quantities of PCBs and DDE/DDT complicated severely their ability to detect and characterize low levels of TCDD. (100 ppm)

24. High Resolution Mass Spectrometry 10000 RP Permits the use of 13C-labeled PCDF standards Resolving Power Requirements [to separate (M+4)+ from labeled PCDFs & M+ from PCDDs] 8,000 for 13C12-TCDF & unlabeled TCDD 9,000 for 13C12-PeCDF & unlabeled PeCDD 10,000 for 13C12-HxCDF & unlabeled HxCDD 11,000 for 13C12-HpCDF & unlabeled HpCDD(no co-elution) 12,000 for 13C12-OCDF & unlabeled OCDD (no co-elution)

25. High Resolution Mass Spectrometry 100ppm 5% line

26. Uncommon terms

27. Sample specific Estimated Quantitation Limit (EQL) More commonly referred to as an EDL, estimated detection limit. The concentration of a given analyte required to produce a signal with a peak height of at least 2.5 times the background signal level. An EDL is typically calculated for each 2,3,7,8-substituted congener that is not identified. Primary DL in Method 8290.

28. Sample specific Estimated Quantitation Limit (EQL)

29. Sample specific Estimated Quantitation Limit (EQL)

30. Estimated Maximum Possible Concentration (EMPC) A detected peak that fails the ion ratio requirement. This peak meets all other qualification requirements (RT, S/N, etc.) and may indicate an interference is present in the peak or failed statistically. Peak could still be a target. Use these concentrations for conservatism or treat as DL, etc. Reported automatically by Method 8290.

31. Estimated Maximum Possible Concentration (EMPC)

32. EMPC

33. Toxic Equivalency Quotient (TEQ) Simplest means of reporting a samples toxicity, one number! TEQ is a sum based on the concentration of the 2378 isomers present and their relative toxicity to the most toxic congener (2378-TCDD). Important client decisions include • the choice of Toxic Equivalency Factors (TEFs) • treatment of non-detects • the use of EMPCs or not.

34. Example Dioxin TEQ

35. Totals First and Last Eluter : Number of Congeners

36. Report examples

37. The 17 2,3,7,8-Substituted Section 1613 Form

38. Totals Section 1613 Form Dioxins Furans

39. TEQ Section 1613 Form

40. Example 8290 Form Same

41. Example DOD Style

42. Example DOD Style