Development and Demonstration of Rapid Analysis of Single- Particle Composition Using Mass Spectrometry

该项目支持建设可现场部署的快速单粒子质谱仪（RSMS）。该仪器将能够提供40至200纳米尺寸范围内单个颗粒的化学和尺寸信息。这将通过使用特殊设计的喷嘴进口选择颗粒的大小，使用准分子激光辐射蒸发颗粒并使用质谱分析碎片来实现。化学成分，如有机碳、单质碳、硫酸盐、甲烷磺酸盐和氯化钠将被区分开来。该信息将是半定量的，因为用相同成分的粒子获得的信号强度在枪弹之间的变化，并且由于该技术对表面物种的偏见。然而，化学计量数据分析技术能够对获得的光谱进行分类，并提取有关气溶胶成分和混合状态（外部与内部）的信息。一旦现场部署仪器的组装完成，它将在当地一个地点进行测试，以在环境空气条件下演示该技术。将对施胶技术进行校准和验证。

9703615 Wexler This project supports the construction of a field-deployable Rapid Single-Particle Mass Spectrometer (RSMS). This instrument will be capable of providing chemical as well as size information on individual particles in the size range of 40 to 200 nm. This will be achieved by size selecting particles with a specially designed nozzle inlet, evaporating the particles using excimer laser radiation and analyzing the fragments using mass spectrometry. Chemical constituents such as organic carbon, elemental carbon, sulfates, methane sulfonates, and sodium chloride will be distinguishable. The information will be semi-quantitative due to shot-to-shot variations in signal intensity obtained with particles of identical composition, and due to a bias of the technique to surface species. However, chemometric data analysis techniques are capable of classifying the obtained spectra and extracting information on the aerosol composition and mixing state (external vs. internal). Once the assembly of the field-deployable instrument is completed, it will be tested at a local site to demonstrate the technique at ambient air conditions. The sizing technique will be calibrated and validated.