COLLABORATIVE RESEARCH: EFFECTS OF CHEMICAL AGING ON THE SURFACE VS. BULK COMPOSITION OF ATMOSPHERIC ORGANIC AEROSOL

化学系的环境化学科学项目支持杰西·H教授。马萨诸塞州理工学院的克罗尔，负责对空气颗粒界面上存在的有机化合物与大部分颗粒内发现的有机化合物之间的化学差异进行实验室研究。正在研究和开发用于实时测量表面成分的新分析技术;这些方法包括烟灰颗粒气溶胶质谱法（SP-AMS，一种基于激光的技术，用于快速蒸发含有黑碳或金属核的颗粒），可调真空紫外光电离（VUV，一种软电离技术）和真实的实时直接分析（DART，一种用于测量材料表面的质谱技术）。这些国家的最先进的技术，然后将用于环境室的研究，检查如何冷凝的次生物质影响有机气溶胶的组成，重点是各种气溶胶成分之间的混合程度和速度。该研究有望为大气有机细颗粒物的形成和演化提供新的见解。直接检查化学梯度和这些颗粒的混合将提供重要的约束其大气行为，反应性和命运，并最终在全球气候和人类健康的作用。

The Environmental Chemical Sciences Program in the Chemistry Division supports Professor Jesse H. Kroll of the Massachusetts Institute of Technology for the laboratory study of chemical differences between organic compounds present at the air-particle interface and those found within the bulk of the particles. New analytical techniques for the real-time measurement of the surface composition are being investigated and developed; these include combinations of soot particle aerosol mass spectrometry (SP-AMS, a laser-based technique for the rapid vaporization of particles containing black carbon or metal cores), tunable vacuum ultraviolet photoionization (VUV, a soft ionization technique), and direct analysis in real time (DART, a mass spectrometric technique for the measurement of material surfaces). These state-of-the-art techniques will then be used in environmental chamber studies, examining how the condensation of secondary species affect organic aerosol composition, with a focus on the extent and rate of mixing between various aerosol components. This study is expected to provide new insights into the formation and evolution of atmospheric organic fine particles. The direct examination of chemical gradients and mixing within such particles will provide important constraints on their atmospheric behavior, reactivity, and fate, and ultimately on their role in global climate and human health.