Advances in offline approaches for trace measurements of complex organic compound mixtures via soft ionization and high-resolution tandem mass spectrometry
Advances in offline approaches for trace measurements of complex organic compound mixtures via soft ionization and high-resolution tandem mass spectrometry
复制标题
通过软电离和高分辨率串联质谱离线测量复杂有机化合物混合物的进展
DOI：
10.1016/j.chroma.2019.03.037
复制
发表时间：
2019
影响因子：
4.1
通讯作者：
Gentner, Drew R.
中科院分区：
文献类型：
--
作者：
Khare, Peeyush;Marcotte, Aurelie;Sheu, Roger;Walsh, Anna N.;Ditto, Jenna C.;Gentner, Drew R.
复杂的空气中有机化合物混合物可以包含10，000多种痕量浓度的化合物。在这里，我们将高分辨率质谱仪纳入集成的离线采样分析测量系统中，用于对气相或颗粒相样品中的复杂混合物进行常规分子水平形态分析，检测限为2-20 pg L-1（即0.2-1.9）6 L样品中的ppt）。通过气相色谱法（GC）分离自定制吸附管（或过滤器浸提液）解吸的分析物，同时通过电子电离四极杆质谱仪（EI-MS）和大气压化学电离（APCI）结合高分辨率四极杆飞行时间质谱仪（Q-TOF）进行分析，HR-TOF和MS/MS模式下的分辨率为25，000 - 40，000 M/ΔM。我们用简单的标准品证明了我们的系统，马孔多原油标准品作为常见空气中化合物的复杂混合物的参考，和环境样品使用GC-TOF和GC-MS/MS。我们在质量准确度误差（即质量公差）降至8 ± 2 ppm（例如，以0.003 u的精度分辨质量为270.000 u的分析物），使用具有3000个分子式的靶向方法，包括烃和含氧的官能化分析物，硫、氮或磷。这从具有10至32个碳原子和每个碳数多达16个烃分子式的化合物延伸，并且官能化化合物类别的范围类似。我们还展示了MS/MS区分结构异构体和确定特定官能团存在的能力;以及我们的直接TOF能力，它绕过高温色谱分离以保留功能化分析物。
Complex airborne mixtures of organic compounds can contain 10,000′s of diverse compounds at trace concentrations. Here, we incorporate high-resolution mass spectrometry into our integrated offline sampling-to-analysis measurement system for routine molecular-level speciation of complex mixtures in gas- or particle-phase samples with detection limits of 2–20 pg L−1(i.e. 0.2–1.9 ppt in 6 L samples). Analytes desorbed from custom adsorbent tubes (or filter extracts) were separated via gas chromatography (GC) and simultaneously analyzed by an electron ionization quadrupole mass spectrometer (EI-MS), and by atmospheric pressure chemical ionization (APCI) combined with a high-resolution quadrupole time-of-flight mass spectrometer (Q-TOF) with a resolution of 25,000–40,000 M/ΔM in HR-TOF and MS/MS modes. We demonstrated our system with simple standards, a Macondo crude oil standard as a reference for complex mixtures of common airborne compounds, and ambient samples using GC-TOF and GC–MS/MS. We speciated complex mixtures at mass accuracy error (i.e. mass tolerance) down to 8 ± 2 ppm (e.g. resolving analytes of mass 270.000 u with 0.003 u accuracy) using a targeted approach with 3000 molecular formulas, including hydrocarbons and functionalized analytes containing oxygen, sulfur, nitrogen, or phosphorous. This extended from compounds with 10 to 32 carbon atoms and up to 16 hydrocarbon formulas per carbon number, and a similar range for functionalized compound classes. We also demonstrated our MS/MS capabilities to differentiate structural isomers and determine the presence of specific functional groups; and our direct-TOF capability, which bypasses high-temperature chromatographic separation to preserve functionalized analytes.