title: Unintentional formed PCDDs, PCDFs, and DL-PCBs as impurities in Chinese pentachloronitrobenzene products.
abstract: Pentachloronitrobenzene (PCNB) products have been reported to contain relatively high levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) as impurities. No data was available for Chinese PCNB products which are still produced and used in China. Therefore, we analysed Chinese PCNB products, including two raw pesticides and three formulations available on the market. In all samples, PCDDs, PCDFs, and dioxin-like polychlorinated biphenyls (DL-PCBs) were detected at levels exceeding Japanese regulation limits. The concentrations of PCDDs and PCDFs (0.16 to 0.93 ng TEQ g(-1)) were lower than the PCNB formulations measured from the Australian market (3.9 ng TEQ g(-1)). However, the Toxic Equivalent (TEQ) contribution from DL-PCBs (0.7 to 2.5 ng TEQ g(-1)) to total TEQ was higher compared to PCDDs and PCDFs. This discovery demonstrated that it is necessary to consider the DL-PCBs impurity in organochlorine pesticides and other organochlorine chemicals in particular chlorinated aromatic compounds for adequate risk assessment. In addition to DL-PCBs, other unintentionally POPs-hexachlorobenzene (HCB) (3.7 to 52 ng g(-1)) and pentachlorobenzene (PeCBz) (0.04 to 0.3 ng g(-1)) which are listed in the Stockholm Convention-were detected in the PCNB samples. The PCNB production steps were assessed for their unintentional POPs formation potential. Thermolysis of the aromatic compounds using iron chloride (FeCl3) as catalyst is suggested as relevant production step for (DL-)PCBs formation. Since the levels in the formulated PCNB recalculated to active ingredient were higher compared to the raw pesticide, the formulation process (e.g., milling) may also have had an influence on additional PCDD/Fs and PCBs formation.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, People's Republic of China. huangjun@tsinghua.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
authors.affiliation: CSD IDEA (Beijing) Institute of Environmental Innovation Co., Ltd., Beijing, 100084, People's Republic of China.
authors.forename: Norimasa
authors.initials: N
authors.lastname: Yamazaki
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, People's Republic of China.
authors.forename: Shubo
authors.initials: S
authors.lastname: Deng
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, People's Republic of China.|POPs Environmental Consulting, Göppingen, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Weber
mesh_terms: D001572:Benzofurans / Q000032:analysis*; D002681:China; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D009578:Nitrobenzenes / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D009578:Nitrobenzenes; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls; C005805:quintozene
keywords: DL-PCBs; HRGC/HRMS; PCDDs; PCDFs; Pentachloronitrobenzene; TEQ