Hundreds of thousands of organic chemicals are present as a complex mixture in the atmosphere. While well-known contaminants such as persistent organic pollutants (POPs) have been studied and characterized, environmental risks and impacts from lesser-known POP-like chemicals are not yet understood. In this study, we conducted a literature review and a pilot study to explore the opportunities and challenges of using passive air samplers and nontargeted analysis for improving our understanding of contaminant mixtures in air. In our approach, nontargeted analysis using gas chromatography coupled with atmospheric pressure chemical ionization and quadrupole time-of-flight mass spectrometry analysis for chlorinated and brominated semi-volatile compounds in passive air samplers deployed with different source contributions using gas chromatography coupled with atmospheric pressure chemical ionization and quadrupole time-of-flight mass spectrometry. Data from the instrumental analysis were processed and analyzed via suspect screening, mass defect and isotope filterings, and in silico fragment predictions. Some lesser-known monocyclic aromatic compounds containing chlorine or bromine were tentatively identified. Chemical space analysis based on predicted physicochemical properties suggests some of the prioritized compounds have POP-like properties such as long-range transport and bioaccumulation potential and deserve more detailed assessment of their contributions to the overall risk of atmospheric chemical mixtures. Information gained from this study will guide further explorations of complex chemical mixtures in air using passive air samplers and nontargeted analysis.

大气中以复杂混合物的形式存在着数十万种有机化学物质。尽管已经研究和表征了众所周知的污染物，例如持久性有机污染物（POPs），但尚未了解环境风险和鲜为人知的类似POP的化学物质的影响。在这项研究中，我们进行了文献综述和初步研究，以探索使用被动式空气采样器和非目标分析来改善我们对空气中污染物混合物的理解的机会和挑战。在我们的方法中 气相色谱结合大气压化学电离和四极杆飞行时间质谱分析无源空气采样器中氯和溴化半挥发性化合物的非目标分析飞行质谱。通过可疑筛查，质量缺陷和同位素过滤以及计算机碎片预测来处理和分析来自仪器分析的数据。初步确定了一些鲜为人知的含氯或溴的单环芳族化合物。根据预测的理化性质进行的化学空间分析表明，某些优先化合物具有POP样性质，例如远距离运输和生物富集潜力，因此应更详细地评估其对大气化学混合物总体风险的贡献。从本研究中获得的信息将指导使用被动空气采样器和非目标分析进一步探索空气中的复杂化学混合物。