Introduction p 1 4 p 5 5 Another factor in method development and application was the large amount of litigation that occurred because of the detection of these compounds in humans as well as the environment. Methods of analysis were required to generate data that could withstand scrutiny in a court of law, which led to the necessity of using methods based on isotope dilution–HRMS techniques. In addition, the rapid growth in high-quality standards and reference materials contributed to substantial improvements in the accuracy and precision of modern methods. The development of analytical methods was also influenced by the need for regulators to be able to evaluate the combined toxicity of a number of compounds that have similar toxic properties to 2,3,7,8-TCDD, but widely varying potencies. This development is so important to the development of analytical methods that we have included a section below on toxicology and TEFs. The bottom line for dioxin methods was that definitive separation of the 2,3,7,8-substituted dioxins/furans and DLPCBs from a large number of other congeners with almost identical physical and chemical properties, as well as numerous other potentially interfering compounds, was essential. Brief background on dioxin determination p 1 1 Fig. 1 p  Table 1 37 Congener Humans/Mammals Fish Birds p 1 1 1 p 1 1 1 p 0.1 0.5 0.05 p 0.1 0.1 0.01 p 0.1 0.1 0.1 p 0.01 0.001 <0.001 p 0.0001 <0.0001 0.001 2,3,7,8-Tetrachlorodibenzofuran (TCDF) 0.1 0.05 1 1,2,3,7,8-Pentachlorodibenzofuran (PeCDF) 0.05 0.05 0.1 2,3,4,7,8-Pentachlorodibenzofuran (PeCDF) 0.5 0.5 1 1,2,3,4,7,8-Hexachlorodibenzofuran (HxCDF) 0.1 0.1 0.1 1,2,3,6,7,8-Hexachlorodibenzofuran (HxCDF) 0.1 0.1 0.1 1,2,3,7,8,9-Hexachlorodibenzofuran (HxCDF) 0.1 0.1 0.1 2,3,4,6,7,8-Hexachlorodibenzofuran (HxCDF) 0.1 0.1 0.1 1,2,3,4,6,7,8-Heptachlorodibenzofuran (HpCDF) 0.01 0.01 0.01 1,2,3,4,7,8,9-Heptachlorodibenzofuran (HpCDF) 0.01 0.01 0.01 1,2,3,4,5,6,7,8-Octachlorodibenzofuran (OCDF) 0.0001 <0.0001 0.001 3,4,4′,5-Tetrachlorobiphenyl (PCB 81) 0.0001 0.0005 0.1 3,3′,4′,4′-Tetrachlorobiphenyl (PCB 77) 0.0001 0.0001 0.05 2′,3,4,4′,5-Pentachlorobiphenyl (PCB 123) 0.0001 0.000005 0.00001 2,3′,4,4′,5-Pentachlorobiphenyl (PCB 118) 0.0001 <0.000005 0.00001 2,3,4,4′,5-Pentachlorobiphenyl (PCB 114) 0.0005 <0.000005 0.0001 2,3,3′,4,4′-Pentachlorobiphenyl (PCB 105) 0.0001 <0.000005 0.0001 3,3′,4,4′,5-Pentachlorobiphenyl (PCB 126) 0.1 0.005 0.1 2,3′,4,4′,5,5′-Hexachlorobiphenyl (PCB 167) 0.00001 <0.000005 0.00001 2,3,3′,4,4′,5-Hexachlorobiphenyl (PCB 156) 0.0005 <0.000005 0.0001 2,3,3′,4,4′,5′-Hexachlorobiphenyl (PCB 157) 0.0005 <0.000005 0.0001 3,3′,4,4′,5,5′-Hexachlorobiphenyl (PCB 169) 0.01 0.00005 0.001 2,3,3′,4,4′,5,5′-Heptachlorobiphenyl (PCB 189) 0.0001 <0.000005 0.00001 5 6 4 5 6 7 4 5 6 7 −12 −15 Representative sampling (not included in this review); Separation of TCDD from the sample matrix (extraction); transfer of TCDD to an appropriate organic solvent; Separation of TCDD from all other organic coextractives (clean-up; can involve several distinct steps); Separation of TCDD from other relatively nontoxic tetrachlorinated dioxin isomers (gas chromatography); Separation and recording of characteristic TCDD molecular fragments using a mass spectrometer. 7 Modern dioxin/furan determination In recent years, methods have built on the early developments referred to above, and have achieved a high degree of sophistication and greatly improved accuracy and precision. The various stages of development of dioxin/furan determination can be generically described as follows: 1970s to 1980s 1980s to 1990s 1990s to 2000s 13 Future focus Toxicology and TEFs 8 11 12 13 14 15 16 17 18 19 20 21 23 24 25 23 Throughout most of its history, the science of toxicology has needed to cope with the effects of only one chemical at a time. HAHs present an unusual challenge to the toxicologist because “real-world” HAH exposure is not to single compounds; rather, HAH exposure involves complex mixtures of dozens to hundreds of congeners from the dioxins (75 possible), furans (135 possible) and PCBs (209 possible). 10 23 26 27 i 28 \documentclass[12pt]{minimal}
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{\text{TEQ = }}\Sigma {\left[ {{\text{PCDD}}_{{\text{i}}}  \times {\text{TEF}}_{{\text{i}}} } \right]} + \Sigma {\left[ {{\text{PCDF}}_{{\text{i}}}  \times {\text{TEF}}_{{\text{i}}} } \right]} + \Sigma {\left[ {{\text{PCB}}_{{\text{i}}}  \times {\text{TEF}}_{{\text{i}}} } \right]}
$$\end{document} Note that the TEF approach applies only to agents that are dioxin-like in that their toxic effects are mediated by the AHR. Noncoplanar PCBs have different mechanisms of action and are not accommodated in the TEF approach. For simplicity it is assumed that all dioxin-like congeners produce toxic responses that are qualitatively the same and that the congeners differ only in their potency to produce these adverse effects, but this simplifying assumption should not be viewed as being true in a literal sense. It is true, however, that the toxic potencies of congeners within the dioxin-like category vary over several orders of magnitude. 28 30 What is the proper TEF for each congener? What is the predominant mode of interaction between congeners when present in a mixture? 27 27 31 32 29 33 34 35 p 1 37 36 Modern methods of analysis 38 38 40 41 42 44 2 Table 2 Regulatory methods for the analysis of dioxins, furans and DLPCBs Method Analytes/Comments Reference USEPA 1613 Seventeen 2,3,7,8-substituted dioxins and furans and congener group totals in water and wastewater. Uses isotope dilution–GC–HRMS 38 USEPA 1668a 209 PCB congeners. 12 WHO dioxin-like PCBs by GC–HRMS, the remaining 197 by GC–MS 39 USEPA 23 Seventeen 2,3,7,8-substituted dioxins and furans and congener group totals in incinerator stack gasses. Uses isotope dilution–GC–HRMS 45 USEPA 8290 (SW-846) Seventeen 2,3,7,8-substituted dioxins and furans and congener group totals in materials and waste. Uses isotope dilution–GC–HRMS 46 ISO 18073 Equivalent to USEPA 1613, also allows GC–MS as an alternate detection method 47 ISO 17858 Twelve WHO dioxin-like PCBs in environmental matrices by GC–HRMS  48 EN 1948 Seventeen 2,3,7,8-substituted dioxins and furans and congener group totals in stationary sources by isotope dilution–GC–HRMS 49 MOE 3418 Seventeen 2,3,7,8-substituted dioxins and furans including congener group totals and 12 WHO dioxin-like PCBs by GC–HRMS. Uses isotope dilution–GC–HRMS 50 ENVCAN 1/RM/19 Seventeen 2,3,7,8-substituted dioxins and furans and congener group totals in pulp and paper effluents by isotope dilution–GC–HRMS 51 JIS K0312 Seventeen 2,3,7,8-substituted dioxins and furans including congener group totals in wastewater by isotope dilution–GC–HRMS 52 JIS K0311 Seventeen 2,3,7,8-substituted dioxins and furans including congener group totals in incinerator stack gasses by isotope dilution–GC–HRMS 53 Overview of analytical process objectives data evaluation 54 Sample extraction methods 55 2 3 56 Table 3 Alternative extraction techniques Matrix Technique  Reference Soil/sediment/solid PLE 42 44 SFE 58 MASE 59 Aqueous SPMD, passive sampling 60 61 SPE 40 41 Air Swipe/biofilms 62 Passive sampling 63 64 40 18 57 Sample extract clean-up methods 6 8 65 66 2 18 67 42 68 69 68 70 71 59 72 50 PCB congener Potential interference PCB 81 PCB 87 PCB 77 PCB 110 PCB 123 PCB 149 PCB 126 PCBs 178 and 129 PCB 156 PCB 171 PCB 157 PCB 201 Gas chromatography columns and methods 73 74 75 76 77 78 80 81 82 84 85 86 85 86 87 88 89 90 178 Mass spectrometry detection methods 91 92 7 93 94 97 98 99 100 85 101 102 2 103 104 105 Alternate methods of analysis 106 110 111 114 115 118 119 122 Quality control and data reporting 13 123 124 125 126 4 127 Table 4 127 Parameter CAS No.  N  N  N  N 2,3,7,8-TCDD 1746-01-6 20 26 19 21 1,2,3,7,8-PeCDD 40321-76-4 25 17 14 21 1,2,3,4,7,8-HxCDD 39227-28-6 15 13 18 16 1,2,3,6,7,8-HxCDD 57653-85-7 17 18 30 29 1,2,3,7,8,9-HxCDD 19408-74-3 19 21 31 24 1,2,3,4,6,7,8-HpCDD 35822-46-9 12 22 38 26 1,2,3,4,5,6,7,8-OCDD 3268-87-9 15 18 31 20 2,3,7,8-TCDF 51207-31-9 15 23 37 23 1,2,3,7,8-PeCDF 57117-41-6 15 20 32 23 2,3,4,7,8-PeCDF 57117-31-4 17 16 31 27 1,2,3,4,7,8-HxCDF 70648-26-9 13 15 29 17 1,2,3,6,7,8-HxCDF 57117-44-9 14 13 34 21 1,2,3,7,8,9-HxCDF 72918-21-9 16 13 35 22 2,3,4,6,7,8-HxCDF 60851-34-5 21 16 31 24 1,2,3,4,6,7,8-HpCDF 67562-39-4 16 13 32 19 1,2,3,4,7,8,9-HpCDF 55672-89-2 11 15 37 16 1,2,3,4,5,6,7,8-OCDF 39001-02-0 21 27 15 33   N N N  PCB 77 3,3’4,4’-TCB 32598-13-3 24 14 14  PCB 81 3,4,4’,5-TCB 70362-50-4 23 16 9  PCB 105 2,3,3,’4,4’-PeCB 32598-14-4 28 71 27  PCB 114 2,3’,4,4’,5-PeCB 74472-37-0 19 17 17  PCB 118 2,3’,4,4’,5-PeCB 31508-00-6 25 90 49  PCB 123 2’,3,4,4’,5-PeCB 65510-44-3 23 22 14  PCB 126 3,3’,4,4’,5-PeCB 57465-28-8 28 15 16  PCB 156 2,3,3’,4,4’,5-HxCB 38380-08-4 19 23 9  PCB 157 2,3,3’,4,4’,5’-HxCB 69782-90-7 32 22 10  PCB 167 2,3’,4,4’,5,5’-HxCB 52663-72-6 21 12 13  PCB 169 3,3’,4,4’,5,5’-HxCB 32774-16-6 25 15 11  PCB 189 2,3,3’,4,4’,5,5’-HpCB 39635-31-9 14 17 12  128 Sources, occurrence and temporal trends in PCDD/Fs 129 130 131 132 138 139 140 133 135 136 141 142 129 143 144 147 144 146 148 141 148 −2 −1 −2 −1 141 149 2 150 144 151 152 −1 151 −1 153 Fig. 2 149  152 154 129 155 156 157 130 158 159 160 5 Table 5 Selected global environmental concentrations of PCDD/Fs Matrix Region Concentration Range Reference Remarks Air Europe 3  Typical rural Air Europe 3  Contaminated area Air Asia 3   Air South America 3   Freshwater Korea 0.001–1.061 pg TEQ/L   Freshwater Japan 0.012–48 pg TEQ/L  2,116 sites Seawater Japan 3  12 sites Seawater Japan 3  21 sites Soil Seveso, Italy 0.91–16 pg TEQ/g   Soil Germany 1–5 pg TEQ/g 143 Rural Soil Germany 30,000 pg TEQ/g 143 Contaminated Soil Germany 10–30 pg TEQ/g 143 Urban Soil The Netherlands 2.2–16 pg TEQ/g 143 Rural Soil The Netherlands 98,000 pg TEQ/g 143 Contaminated Soil United Kingdom <1–20 pg TEQ/g 143 Rural Soil United Kingdom 1,585 pg TEQ/g 143 Contaminated Soil New Zealand 0.17–1.99 pg TEQ/g 143 Rural Soil New Zealand 260–6,670 pg TEQ/g 143 Urban Sediments Lake Ontario 91 pg TEQ/g 165 Lakewide average Sediments Po River 1–11 pg TEQ/g 166  Sediments Lake Baikal 0.03 pg TEQ/g   Sediments Japan 16.1–50.7 pg TEQ/g   Sediments New Zealand 0.081–2.71 pg TEQ/g   Marine sediments North Sea 5.5–17.2 pg TEQ/g   Marine sediments Gulf of Finland 101,000 pg TEQ/g  Highly contaminated Marine sediments Catalan coast 0.4–8 pg TEQ/g 167  Marine sediments Japan 0.012–49.3 pg TEQ/g   Vegetation Germany 0.53–1.64 pg TEQ/g  Pine needles Vegetation Austria 0.3–1.9 pg TEQ/g  Spruce needles Birds and animals India 19–24 pg/g fat 168 Eagle Birds and animals India 150–200 pg/g fat 168 Osprey Birds and animals India 9.2–270 pg/g fat 168 Spotted Owlet Birds and animals India 1,300–2,700 pg dioxins/g fat 168 Spotted Owlet liver Birds and animals India 620-1,000 pg furans/g fat 168 Spotted Owlet liver Fish Great Lakes <1–63 pg TEQ/g 169  Fish Great Lakes <1–59 pg TEQ/g 170 Dioxin TEQ Fish Great Lakes <1–182 pg TEQ/g 170 PCB TEQ Fish Finnish coast 165–329 pg TEQ/g lipid 171 Herring muscle Fish Adriatic Sea 0.23–329 pg TEQ/g lipid 171 Mackerel>Red mullet>Anchovy Fish Japan Sea 0.10–0.95 pg TEQ/g  Cod Marine mammals Bird Island 2 pg TEQ/g blubber 172 Fur seals Marine mammals Canadian Arctic 2–23 pg TEQ/g ww 173 Polar bears Marine mammals Japan Sea 0.71–13 pg TEQ/g ww  Whale Marine mammals Japan Sea 17–360 pg TEQ/g ww  Whale fat Marine mammals Australia 0.1–2.6 ng/g ww  Bottlenose dolphin Food Europe 0.3–2.5 pg TEQ/g fat 174 Milk and dairy products Food North America 0.3–0.9 pg TEQ/g fat 174 Milk and dairy products Food South America 0.01–2.8 pg TEQ/g fat 174 Milk and dairy products Food Asia 0.3–1.8 pg TEQ/g fat 174 Milk and dairy products Human milk The Netherlands 17.09–21.29 pg TEQ/g fat   Human milk Ukraine 8.38–10.16 pg TEQ/g fat   Human milk Norway 7.16–7.43 pg TEQ/g fat   Human milk Czech Republic 7.44–10.73 pg TEQ/g fat   Human milk Bulgaria 5.08–7.11 pg TEQ/g fat   Blood/serum/plasma Great Lakes 27.5 ng TEQ/L 175 Recreational fishers Blood/serum/plasma Israel 26.6–32 ng TEQ/g fat 176  Blood/serum/plasma A So, Vietnam 16.6–45.9 pg TEQ/g lipid 177  Blood/serum/plasma New Zealand 12.8 pg TEQ/g serum fat 143 1,834 samples 160  ND ww 161 162 163 164 129 161 161 144 147 146 147 161 163