Authors: Jun Huang Jie Gao Gang Yu Norimasa Yamazaki Shubo Deng Bin Wang Roland Weber
Publish Date: 2014/08/30
Volume: 22, Issue: 19, Pages: 14462-14470
Abstract
Pentachloronitrobenzene PCNB products have been reported to contain relatively high levels of polychlorinated dibenzopdioxins 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 dioxinlike polychlorinated biphenyls DLPCBs were detected at levels exceeding Japanese regulation limits The concentrations of PCDDs and PCDFs 016 to 093 ng TEQ g−1 were lower than the PCNB formulations measured from the Australian market 39 ng TEQ g−1 However the Toxic Equivalent TEQ contribution from DLPCBs 07 to 25 ng TEQ g−1 to total TEQ was higher compared to PCDDs and PCDFs This discovery demonstrated that it is necessary to consider the DLPCBs impurity in organochlorine pesticides and other organochlorine chemicals in particular chlorinated aromatic compounds for adequate risk assessment In addition to DLPCBs other unintentionally POPs—hexachlorobenzene HCB 37 to 52 ng g−1 and pentachlorobenzene PeCBz 004 to 03 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 DLPCBs formation Since the levels in the formulated PCNB recalculated to active ingredient were higher compared to the raw pesticide the formulation process eg milling may also have had an influence on additional PCDD/Fs and PCBs formation
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