Simultaneous Measurements of Individual Ambient Particle Size, Composition, Effective Density, and Hygroscopicity

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• 作者：Alla Zelenyuk ; Dan Imre ; Jeong-Ho Han ; Susan Oatis
• 刊名：Analytical Chemistry
• 出版年：2008
• 出版时间：March 1, 2008
• 年：2008
• 卷：80
• 期：5
• 页码：1401 - 1407
• 全文大小：191K
• 年卷期：v.80,no.5(March 1, 2008)
• ISSN：1520-6882

文摘

The interaction between atmospheric particles and watervapor impacts directly and significantly the effect thatthese particles exert on the atmosphere. The hygroscopicity of individual particles, which is a quantitative measureof their response to changes in relative humidity, is relatedto their internal compositions. To properly include atmospheric aerosols in any model requires knowledge of therelationship between particle size, composition, and hygroscopicity. Here we demonstrate the capability to conduct in real time the simultaneous measurements ofindividual ambient particle hygroscopic growth factors,densities, and compositions using a humidified tandemdifferential mobility analyzer that is coupled to an ultrasensitive single-particle mass spectrometer. We use as anexample the class of particles that are composed of sulfatemixed with oxygenated organics to illustrate how multidimensional single-particle characterization can be extended to yield in addition quantitative information aboutthe composition of individual particles. We show that thedata provide the relative concentrations of organics andsulfates, the density of the two fractions, and particlehygroscopicity.