Development and application of a comprehensive thermal desorption/photoionisation mass spectrometry instrument for the determination of the nature of the carbonaceous fraction and the oligomeric/polymeric content of ambient participate matter

更好地了解对流层气溶胶中含碳物质的化学成分对气候和健康研究非常重要。最近的调查显示，除了挥发性和半挥发性有机物质（OC）以及所谓的基本碳组分（EC）外，城市气溶胶中还存在聚合物（例如类似腐殖质的物质）和高极性、多功能化合物（例如糖衍生物）。这对含碳二次气溶胶粒子（SOA）尤其有效。气溶胶的低挥发性有机成分到目前为止还很难分析得到。应用创新的热方法来测定OC和EC馏分，通过释放颗粒物质（PM）的碳质部分采样的过滤器从大约的温度步骤的连续。100至850°C（通过解吸，热解和氧化）可以检测化学上不同的键合碳作为非特异性和参数。在提议的项目中，将开发一种新的分析技术，通过该技术，释放碳质分子或热解产物的热分析方法与新的光电离质谱仪（软单光子和多光子电离，SPI和REMPI）连在一起。这样一来，对进化产物的直接化学分析就成为可能。一项成功的初步可行性研究表明，在高达340°C的温度范围内，可检测到PM的分子成分，例如多环芳烃以及聚合物气溶胶成分的热解产物。在新技术的开发和优化之后，除了改进碳质PM的低聚和聚合部分的特征外，还将尝试区分SOA的人为和生物部分。

A better understanding of the chemical composition of carbonaceous material from tropospheric aerosol is very important with respect to climatic and health research. Recent investigations revealed that in addition to volatile and semivolatile organic species (OC) as well as so called elementary carbon fractions (EC) also polymeric (e.g. humic like substances) and highly polar, polyfunctional compounds (e.g. sugar derivatives) are present in urban aerosol. This is especially valid also for carbonaceous secondary aerosol particles (SOA). Low volatile organic constituents of aerosol are hardly accessible analytically up to now. Applying innovative thermal methods for determination of OC and EC fractions by releasing the carbonaceous portion of particulate matter (PM) sampled on filter with a succession of temperature steps from approx. 100 to 850 °C (by desorption, pyrolysis, and oxidation) enables detection of chemically different bonded carbon as non-specific sum parameters. In the proposed project a novel analytical technique will be developed, by which the thermal analytical method for releasing carbonaceous molecules or pyrolysis products is hyphenated with a new photo ionisation mass spectrometer (soft single and multi photon ionisation, SPI and REMPI). By doing so, a direct chemical analysis of the evolved products is possible. A successful preliminary feasibility study in the temperature range up to 340°C showed, that molecular components of PM, e.g. polycyclic aromatic hydrocarbons as well as pyrolysis products of polymeric aerosol constituents are detectable. After development and optimisation of the novel technique, in addition to an improved characterisation of oligomeric and polymeric fractions of carbonaceous PM distinction of anthropogenic and biogenic portions of SOA will be attempted.