城市不同源大气VOCs单体稳定同位素组成及影响研究

It is often necessary to allocate a contamination to a specific source in order to allow appropriate means of risk reduction and/or to identify responsible parties in litigation. Traditional approaches in environmental forensics use chemical fingerprinting, biomarker analysis, and chemometrics, however Organic pollutants in the environment will experience a variety of complex behavior, such as proliferation, migration, adsorption, sedimentation, and degradation, the commonly used abundance-based source identification methods have considerable limitations and uncertainties. In this project, a novel sandwich-style sampling train was designed to enrich and pre-classify the volatile organic compounds in ambient air for CSIA, all the samples collected from the sources and the functional areas in the urban will be analyzed by two-step thermal desorption-gas chromatography -mass spectrometry\stable isotope mass spectrometry (TD-GC-MS\IRMS), a three-dimensional fingerprint map , including the information of the composition, abundance and compound-specific stable isotope ratios of the main compounds will be drawn, we wish that from the comparison of the 3D fingerprint map of the sources and the main functional areas we could revealing the potential sources, migration path and the sphere of influence of these organic pollutants in ambient air, and the result of this research could provide a new method and reliable evidence for the urban atmospheric environment forensics.

城市大气环境治理需要对污染源准确归属。由于有机污染物在环境中将经历如扩散、迁移、吸附、沉降、降解等多种复杂行为，传统基于化合物丰度为依据的源识别方法具有相当的局限性和不确定性。本项目采用单体稳定同位素技术系统研究城市挥发源和不同功能区大气中VOCs的同位素组成和影响，针对同位素质谱仪仪器灵敏度低、分离度要求高的局限，设计三明治式复合吸附剂采样技术，分类富集VOCs。项目将通过二级热脱附系统与气相色谱-质谱\稳定同位素质谱仪（TD-GC-MS\IRMS）联用技术，构建包含城市VOCs源和不同功能区VOCs的组成、丰度和稳定同位素比率三维信息的指纹图谱，多角度验证，辨识归属，避免了传统单一组成或浓度相关溯源方法的不确定性，为源分析提供直观、确凿的证据；通过对挥发源和各功能区三维信息的解析，揭示城市空气中有机物来源、迁移途径和影响范围，为城市大气环境监管和污染控制提供新的研究方法和科学依据。

本项目研究以厦门岛为例，利用单体稳定同位素技术研究城市不同源大气VOCs稳定同位素组成和影响。系统调查了不同挥发源和城市不同功能区大气样品中各挥发性有机物单体稳定同位素组成。结合传统的主成分模型分析溯源方法，确定不同源和城市各功能区有机物的种类、浓度和主导化合物同位素丰度比率范围，构建涵盖大气样品三维信息因子的指纹图谱。并与多个排放源进行比对，多角度验证，辨识归属，实现对城市大气主要污染源的溯源分析。