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氯化石蜡(chlorinated paraffins,CPs)是一组人工合成的氯代烷烃混合物,其通式为CnH2n+2-mClm. 由于CPs化学性质稳定以及具有良好的阻燃性,其被广泛用作阻燃剂和增塑剂添加到塑料、革制品和纺织材料等产品中[1 − 3]. CPs按照碳链长度可分为短链氯化石蜡(SCCPs,C10—13)、中链氯化石蜡(MCCPs,C14—17)和长链氯化石蜡(LCCPs,>C17). 其中,SCCPs因其具有持久性、远距离迁移能力以及生物累积性等特性,在2017年被列为《关于持久性有机污染物的斯德哥尔摩公约》(POPs公约)中的A类受控污染物[4]. MCCPs由于与SCCPs相似的环境行为及毒性效应,于2023年被建议将氯含量不低于45%的MCCPs列入POPs公约[5]. 因此,我国面临SCCPs和MCCPs的双重履约重任,亟需对我国SCCPs和MCCPs的环境存量、排放清单开展深入系统研究.
2021年,我国聚氯乙烯(PVC)塑料及其制品的生产量及消费量达到21.3 Mt和19.9 Mt,需求旺盛[6]. 同时,我国也是CPs主要的生产国和消费国,CPs年产量约在1 Mt左右[7 − 8]. 国内约70%的CPs产品主要作为塑化剂和阻燃剂被添加到PVC塑料中[9]. 2019年,我国约有13.2—208.3 kt SCCPs和11.2—334.3 kt MCCPs被用于PVC生产[10]. 含SCCPs和MCCPs的PVC塑料被广泛应用于各行业将对人体健康暴露造成风险[11 − 13].
我国和欧盟发布了皮革及玩具制品中氯化石蜡的检测方法标准,规定的检测仪器为气相色谱-负化学源质谱和液相色谱-二级串联质谱[14 − 16]. 针对环境介质中氯化石蜡检测多采用色谱-负化学源低分辨质谱法[17 − 19]. 采用常规低分辨质谱法时,CPs同系物间难以在色谱上实现完全分离,且质谱上存在质量干扰而难以准确定量. 气相-静电场轨道阱高分辨质谱(GC-Orbitrap-HRMS)因其高灵敏度、高分辨率、高通量的优势,而广泛用于复杂基质新污染物的定性与定量分析[20 − 21]. 近年来,已有报道基于超高效液相-静电场轨道阱高分辨质谱(UHPLC-Orbitrap-HRMS)、高效液相-四极杆飞行时间质谱(HPLC-Q-TOF-MS)和四极杆飞行时间质谱(Q-TOF-MS)直接进样等测定环境等介质中氯化石蜡的赋存水平[22 − 26],但对塑料产品中CPs研究尚在起步阶段[27],罕有针对PVC塑料制品的超高分辨质谱定量分析方法. 本研究采用气相色谱-负化学源静电场轨道阱高分辨质谱(GC-NCI-Orbitrap-HRMS)定量分析5类典型PVC塑料中SCCPs和MCCPs,采用全扫描方式对64种氯原子数为5—12的SCCPs和MCCPs同系物进行监测,有效避免同系物间质量干扰,提高定量结果准确性. 同时开展PVC产品中SCCPs和MCCPs的浓度水平分析并评估其年排放水平,对我国氯化石蜡管控以及为健康暴露风险提供数据基础具有重要意义.
市售聚氯乙烯(PVC)塑料制品中短链及中链氯化石蜡含量分析及排放预测
Determination and emission estimation of short-chain and medium-chain chlorinated paraffins in PVC plastic products
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摘要: 氯化石蜡(chlorinated paraffins,CPs)是一系列正构烷烃氯代混合物,常用作阻燃和塑化添加剂. 其中,短链氯化石蜡(SCCPs)和中链氯化石蜡(MCCPs)具备典型持久性有机污染物属性. 作为聚氯乙烯(PVC)最大的生产和消费国,我国约有70%CPs产品被添加到PVC塑料当中,其添加SCCPs和MCCPs的含量水平和潜在排放暴露风险需要重点关注. 本研究采用气相色谱-静电场轨道阱高分辨质谱(GC-Orbitrap-HRMS)检测市售5类25种典型PVC塑料中SCCPs和MCCPs水平. 结果表明,塑料中SCCPs和MCCPs的浓度范围为0.010—64.2 mg·g−1和0.002—50.9 mg·g−1,不同样品间的SCCPs和MCCPs的含量差异明显,浓度水平依次为线缆>地毯/垫>地板革>硬管>布线槽. 不同材料中SCCPs同系物分布存在差异,线缆护套和地毯/垫中C13-CPs为SCCPs的主要同族体,地板革中SCCPs以C10-CPs为主,硬管和布线槽中各碳同族体相对丰度无显著差异. MCCPs在所有材料中分布模式相似,均以C14-CPs为主. SCCPs以Cl7和Cl8为主,MCCPs的氯分布更为集中,以Cl8为主. 通过排放预测模型评估了5类PVC塑料中SCCPs和MCCPs向空气、地表水和土壤中的年最大排放量,分别为2.73 kt(空气)、0.82 kt(地表水)以及0.11 kt(土壤),确定PVC塑料的生产及使用是环境中SCCPs和MCCPs的重要排放源.
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关键词:
- 气相色谱-静电场轨道阱高分辨质谱 /
- 短链氯化石蜡 /
- 中链氯化石蜡 /
- PVC塑料 /
- 排放评估.
Abstract: Chlorinated paraffins (CPs) are a series of synthetic chlorinated n-alkanes, which are widely used as flame retardants and plasticizers. Among them, short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) attract worldwide attentions due to their persistence, long range transportation, bioaccumulation and toxicity, which have been included as persistent organic pollutants (POPs) and candidate POPs, respectively. China is the largest producer and consumer of polyvinyl chloride (PVC) products, in which approximately 70% of CP products have been applied. Therefore, the concentrations of SCCPs and MCCPs in commercial PVC products and their potential exposure risk should be a critical concern. In this study, chromatography-orbitrap-high-resolution mass spectrometry (GC-Orbitrap-HRMS) was adopted to determine the concentrations and congener pattern characteristics of SCCPs and MCCPs in 25 species in five PVC product categories. Their concentrations were in the range of 0.010—64.2 mg·g−1 for SCCPs and 0.002—50.9 mg·g−1 for MCCPs, respectively. It differed a lot among the individual samples, following cable>PVC mat>PVC flooring>pipe>groove. The C13-CPs predominated in SCCP congener patterns in carpets/mats and cables, while the C10-CPs exhibited the highest relative abundance in flooring. No significant differences of SCCP congener patterns were found in the pipe and groove. The congener patterns of MCCPs were similar in all the test products, with the C14-CPs in majority. From the perspective of chlorine distribution characteristics, the abundances of Cl7 and Cl8 congeners of SCCPs were dominated while MCCPs was predominated by Cl8 congeners. The annual emissions of SCCPs and MCCPs from these five PVC product categories were evaluated by the emission prediction mode, the maximum emissions of which were 2.73 kt (air), 0.82 kt (surface water) and 0.11 kt (soil), respectively. The production and use of PVC products was indicated as a potential source of SCCPs and MCCPs released to the environment. -
表 1 不同塑料制品中SCCPs和MCCPs分析方法对照
Table 1. Comparison of analysis of SCCPs and MCCPs in plastic products
样品
Sample type检测仪器
Instrument离子源
Ion source方法检出限
Method detection limit参考文献
ReferencePVC塑料 GC-Orbitrap-HRMS NCI SCCPs:9.6 ng∙g−1
MCCPs:9.0 ng∙g−1本研究 PVC、PET、PP和PE等 GC-Q-TOF-MS NCI SCCPs:7.2 ng∙g−1
MCCPs:19.4 ng∙g−1[29] 塑料玩具 GC-LRMS NCI SCCPs:36 μg∙g−1 [30] PVC、橡胶和皮革等 GC-LRMS NCI SCCPs:50 μg∙g−1
MCCPs:50 μg∙g−1[10] PVC LC-MS/MS ESI CPs同系物:1—10 μg∙g−1 [31] 背包 GC-LRMS NCI SCCPs:5 mg∙L−1 [32] 表 2 PVC塑料中SCCPs和MCCPs质量浓度及氯含量
Table 2. Mass concentration and chlorine content of SCCPs and MCCPs in PVC products
样品编号
Sample IDSCCPs MCCPs 浓度/(mg∙g−1)
Concentration氯含量/(%Cl)
Chlorine content浓度/(mg∙g−1)
Concentration氯含量/(%Cl)
Chlorine contentPVC线缆
PVC CableC1 34.8 63.4 21.0 60.6 C2 29.5 63.3 11.6 60.2 C3 35.3 63.4 15.8 59.6 C4 64.2 63.8 50.9 60.9 C5 30.2 62.2 25.2 58.7 C6 20.2 63.5 20.5 59.9 C7 6.01 62.8 6.22 59.0 PVC地毯
PVC MatM1 0.524 61.3 20.2 59.6 M2 15.1 63.0 7.22 59.6 M3 0.042 62.7 0.115 58.0 M4 6.59 60.9 21.5 58.5 M5 10.2 64.3 5.10 60.6 M6 0.105 63.0 0.029 59.1 PVC地板革
PVC FlooringF1 0.010 63.0 0.002 58.4 F2 3.45 64.8 2.30 60.7 F3 0.020 62.9 0.035 58.5 F4 2.40 64.6 1.71 60.8 F5 0.957 63.4 0.496 59.2 F6 0.039 63.9 0.014 59.6 PVC硬管
PVC PipeP1 0.056 62.9 0.026 58.9 P2 1.76 63.1 0.614 59.1 P3 0.874 63.6 0.601 59.2 PVC布线槽
PVC GrooveT1 0.012 62.8 0.015 59.4 T2 0.011 62.7 0.003 58.7 T3 0.010 62.8 0.003 58.8 表 3 2022年5类PVC塑料中SCCPs和MCCPs年最小估计排放量(kt)
Table 3. Minimum emission of SCCPs and MCCPs from five typical PVC products in China in 2022(kt)
PVC塑料
PVC productsSCCPs MCCPs 空气
Air地表水
Surface water土壤
Soil空气
Air地表水
Surface water土壤
Soil生产端
Production线缆 Cable 6.59×10−3 9.06×10−3 4.12×10−3 6.09×10−3 8.38×10−3 3.81×10−3 地毯/垫 Mat 3.73×10−5 5.12×10−5 2.33×10−5 2.63×10−5 3.61×10−5 1.64×10−5 地板革 Flooring 1.53×10−5 2.11×10−5 9.59×10−6 3.04×10−6 4.18×10−6 1.90×10−6 硬管 Pipe 3.24×10−4 4.46×10−4 2.03×10−4 1.49×10−4 2.05×10−4 9.33×10−5 布线槽 Groove 3.45×10−6 4.74×10−6 2.15×10−6 1.07×10−6 1.47×10−6 0.67×10−6 消费端
Consumption线缆 Cable 2.28×10−2 2.28×10−2 — 2.11×10−2 2.11×10−2 — 地毯/垫 Mat 1.29×10−4 1.29×10−4 — 9.11×10−5 9.11×10−5 — 地板革 Flooring 5.32×10−5 5.32×10−5 — 1.05×10−5 1.05×10−5 — 硬管 Pipe 1.12×10−3 1.12×10−3 — 5.17×10−4 5.17×10−4 — 布线槽 Groove 1.19×10−5 1.19×10−5 — 3.72×10−6 3.72×10−6 — 合计
Sum3.11×10−2 3.37×10−2 4.35×10−3 2.80×10−2 3.04×10−2 3.92×10−3 注: “—”, 无对应排放因子. Note: “—”, no relevant emission factor. 表 4 2022年5类PVC塑料中SCCPs和MCCPs年最大估计排放量(kt)
Table 4. Maximum emission of SCCPs and MCCPs from five typical PVC products in China in 2022(kt)
PVC塑料
PVC productsSCCPs MCCPs 空气
Air地表水
Surface water土壤
Soil空气
Air地表水
Surface water土壤
Soil生产端
Production线缆 Cable 8.05×10−1 8.68×10−2 3.94×10−2 6.38×10−1 6.88×10−2 3.13×10−2 地毯/垫 Mat 1.72×10−1 1.86×10−2 8.43×10−3 2.45×10−1 2.64×10−2 1.20×10−2 地板革 Flooring 6.68×10−2 7.21×10−3 3.28×10−3 4.46×10−2 4.80×10−3 2.18×10−3 硬管 Pipe 1.30×10−1 1.41×10−2 6.39×10−3 4.55×10−2 4.90×10−3 2.23×10−3 布线槽 Groove 5.70×10−5 6.14×10−6 2.79×10−6 6.61×10−5 7.13×10−6 3.24×10−6 消费端
Consumption线缆 Cable 2.19×10−1 2.19×10−1 — 1.73×10−1 1.73×10−1 — 地毯/垫 Mat 4.68×10−2 4.68×10−2 — 6.66×10−2 6.66×10−2 — 地板革 Flooring 1.82×10−2 1.82×10−2 — 1.21×10−2 1.21×10−2 — 硬管 Pipe 3.54×10−2 3.54×10−2 — 1.24×10−2 1.24×10−2 — 布线槽 Groove 1.55×10−5 1.55×10−5 — 1.80×10−5 1.80×10−5 — 合计
Sum1.49×100 4.46×10−1 5.75×10−2 1.24×100 3.69×10−1 4.77×10−2 注: “—”, 无对应排放因子. Note: “—”, no relevant emission factor. -
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