State Key Laboratory of Heavy Oil Processing, China University of Petroleum , Beijing 102249, People's Republic of China.
Environ Sci Technol. 2014 May 6;48(9):4716-23. doi: 10.1021/es405295p. Epub 2014 Apr 18.
Aromatic fractions derived from aerosol samples were characterized by gas chromatography and mass spectrometry (GC-MS), high temperature simulated distillation (SIMDIS), and positive-ion atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), respectively. It was found that about 27 wt % compounds in aromatic fractions could not be eluted from a GC column and some large molecule PAHs were neglected in GC-MS analysis. APPI FT-ICR MS was proven to be a powerful approach for characterizing the molecular composition of aromatics, especially for the large molecular species. An aromatic sample from Beijing urban aerosol was successfully characterized by APPI FT-ICR MS. Results showed that most abundant aromatic compounds in PM2.5 (particles with aerodynamic diameter ≤ 2.5 μm) were highly condensed hydrocarbons with 4-8 aromatic rings and their homologues with very short alkyl chains. Furthermore, heteroatom-containing hydrocarbons were found as the significant components of the aromatic fractions: O1, O2, N1, and S1 class species with 10-28 DBEs (double bond equivalents) and 14-38 carbon numbers were identified by APPI FT-ICR MS. The heteroatom PAHs had similar DBEs and carbon number distribution as regular PAHs.
分别采用气相色谱-质谱联用仪（GC-MS）、高温模拟蒸馏（SIMDIS）和正离子大气压光电离（APPI）傅里叶变换离子回旋共振质谱仪（FT-ICR MS）对气溶胶样品中的芳香族馏分进行了表征。结果表明，约 27wt%的芳香族馏分化合物无法从 GC 柱中洗脱出来，且 GC-MS 分析中忽略了一些大分子多环芳烃。APPI FT-ICR MS 被证明是一种用于表征芳烃分子组成的强大方法，特别是对于大分子物质。采用该方法成功地对北京城市气溶胶中的芳香族馏分进行了表征。结果表明，PM2.5（空气动力学直径≤2.5μm 的颗粒物）中含量最丰富的芳香族化合物是高度缩合的多环芳烃，具有 4-8 个芳香环及其烷基链极短的同系物。此外，还发现含杂原子的碳氢化合物是芳香族馏分的重要组成部分：通过 APPI FT-ICR MS 鉴定出具有 10-28 个双键当量（DBE）和 14-38 个碳原子数的 O1、O2、N1 和 S1 类物质。含杂原子的多环芳烃与常规多环芳烃具有相似的 DBE 和碳原子数分布。
