Abstract Pyrolysis-gas chromatography coupled with atmospheric pressure chemical ionization-high resolution time-of-flight mass spectrometry (Py-GC-APCI-TOFMS) was applied for the reliable identification of polymer species in a complex mixture to establish this system as a platform for environmental microplastic analysis. The method was evaluated on a model sample of mixed microplastics comprised of five major polymers: polyethylene (PE), polypropylene (PP), poly(vinyl chloride) (PVC), polystyrene (PSt), and poly(ethylene terephthalate) (PET). The representative ions in the mass spectra of the pyrolyzates were identified by Py-GC-APCI-TOFMS measurements of the individual polymer species. The unique APCI ionization/fragmentation process and the high mass resolution of TOFMS were exploited to confirm the presence of the respective polymer species in the extracted ion chromatograms (EICs) of the mixed sample for the selected key ions. PE and PP were successfully and uniquely identified in the mixed sample by focusing on specific fragment ions of the pyrolyzates formed during APCI (m/z 114.093 ± 0.020 and m/z 156.139 ± 0.020, respectively). The resultant EICs allowed for the specific analysis of these species, even in the presence of interfering species produced from the other polymers. Similar processes were applied to the detection of PVC, PSt, and PET in the mixed sample. These results demonstrated that Py-GC-APCI-TOFMS is a promising tool to characterize a complex mixture of environmental microplastics.

中文翻译：

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通过热解-气相色谱-大气压化学电离-高分辨率飞行时间质谱法鉴定复杂混合物中的聚合物物种作为环境微塑料分析的基础

摘要 将热解-气相色谱联用大气压化学电离-高分辨率飞行时间质谱 (Py-GC-APCI-TOFMS) 用于复杂混合物中聚合物种类的可靠鉴定，以建立该系统作为平台。用于环境微塑料分析。该方法是在由五种主要聚合物组成的混合微塑料模型样品上进行评估的：聚乙烯 (PE)、聚丙烯 (PP)、聚氯乙烯 (PVC)、聚苯乙烯 (PSt) 和聚对苯二甲酸乙二醇酯 (PET) . 热解物质谱中的代表性离子通过单个聚合物种类的 Py-GC-APCI-TOFMS 测量来确定。利用独特的 APCI 电离/碎裂过程和 TOFMS 的高质量分辨率来确认所选关键离子的混合样品的提取离子色谱图 (EIC) 中存在相应的聚合物种类。通过关注 APCI 期间形成的热解产物的特定碎片离子（分别为 m/z 114.093 ± 0.020 和 m/z 156.139 ± 0.020），成功且唯一地鉴定了混合样品中的 PE 和 PP。所得 EIC 允许对这些物质进行特定分析，即使存在由其他聚合物产生的干扰物质。类似的过程应用于检测混合样品中的 PVC、PSt 和 PET。这些结果表明，Py-GC-APCI-TOFMS 是表征环境微塑料复杂混合物的一种很有前途的工具。