多氯二苯并对二恶英和二苯并呋喃(PCDD/Fs)和短链氯化石蜡(短链氯化石蜡)可以在氯化石蜡(CPs)的生产过程中形成。CP中PCDD/Fs的检测和准确定量由于其矩阵复杂性而具有挑战性。因此,过去尚未对CPs产生PCDD/Fs的发生和形成机制进行广泛的研究。在这项研究中,2022年从中国收集了15个商业样品,包括固体和液体CP。在固体和液体CPs中检测到的平均ΣSCCP浓度为158和137mg/g,分别。固体和液体CP中2,3,7,8-PCDD/F的平均国际毒性当量(I-TEQ)值分别为15.8pgI-TEQ/g和15.0pgI-TEQ/g,分别。固体和液体CPs对短链氯化石蜡和PCDD/Fs具有不同的主要同源基团。通过在石蜡中筛选前体和实验室规模的CP热化学实验,分析了生成PCDD/Fs的可能形成途径。2,3,7,8-PCDD/Fs与非2,3,7,8-PCDD/Fs之间的转换是通过计算连续的氯化偏好来识别的。在CP商业产品中首次报告的PCDD/F的出现表明,接触CP和下游产品可能是PCDD/F排放的可分配来源,这对进一步探讨PCDD/Fs在CPs全生命周期中的控制因素具有重要意义。
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and short-chain chlorinated paraffins (SCCPs) can be formed during the production of chlorinated paraffins (CPs). Detection and accurate quantification of PCDD/Fs in CPs are challenging because of their matrix complexity. Therefore, the occurrence and formation mechanisms of PCDD/Fs from CPs have not been studied extensively in the past. In this study, 15 commercial samples including solid and liquid CPs were collected in 2022 from China. The average ΣSCCP concentrations detected in the solid and liquid CPs were 158 and 137 mg/g, respectively. The average International Toxic Equivalent (I-TEQ) values of 2,3,7,8-PCDD/F in solid and liquid CPs were 15.8 pg I-TEQ/g and 15.0 pg I-TEQ/g, respectively. The solid and liquid CPs had different predominant congener groups for SCCPs and PCDD/Fs. Possible formation routes for the generation of PCDD/Fs were analyzed by screening precursors in paraffin and laboratory-scale thermochemical experiments of CPs. The transformation between 2,3,7,8-PCDD/Fs and non-2,3,7,8-PCDD/Fs was recognized by calculating the successive chlorination preference. The first reported occurrence of PCDD/Fs in CP commercial products indicated that exposure to CPs and downstream products might be an assignable source of PCDD/F emission, which is of great significance to further explore the control factors of PCDD/Fs in the whole life cycle of CPs.