Sulfur speciation in individual aerosol particles
Sulfur speciation in individual aerosol particles
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DOI：
10.1029/96jd01555
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发表时间：
1996-08-20
影响因子：
4.4
通讯作者：
Wexler, AS
中科院分区：
文献类型：
--
作者：
Neubauer, KR;Sum, ST;Wexler, AS
硫气溶胶在酸沉降和地球能量平衡中起着重要作用。这些气溶胶中的重要物质包括甲烷磺酸盐、羟基甲烷磺酸盐、硫酸盐和亚硫酸盐。由于这些种类的相对数量表明了不同的来源和大气过程，因此必须在单个气溶胶颗粒中区分它们。为了完成这一任务，我们使用快速单粒子质谱（RSMS），一种允许单个粒子进行在线模式分析的技术。每种硫物质在质谱中产生一组特征离子。在模拟的海洋和城市气溶胶中，甲磺酸（MSA）和羟基甲磺酸钠（NaHMSA）在单个颗粒中的相对量可以由质谱中的峰面积比确定。通过应用分类和回归树（CART）算法来区分具有不同组成的颗粒的质谱，可以改进定量。影响物种形成的因素包括颗粒大小、形态和激光能量密度。
Sulfur aerosols play an important role in acid deposition and the Earth's energy balance. Important species in these aerosols include methanesulfonates, hydroxymethanesulfonates, sulfates, and sulfites. Because the relative amounts of these species indicate different sources and atmospheric processes, it is important to distinguish them in single-aerosol particles. To accomplish this task, we use rapid single-particle mass spectrometry (RSMS), a technique that permits individual particles to be analyzed in an on-line mode. Each sulfur species produces a characteristic set of ions in the mass spectra. In simulated marine and urban aerosols the relative amounts of methanesulfonic acid (MSA) and sodium hydroxymethanesulfonate (NaHMSA) in a single particle can be determined from peak area ratios in the mass spectra. Improved quantitation is possible by application of the classification and regression tree (CART) algorithm to distinguish the mass spectra of particles having different compositions. Factors that influence speciation include particle size, morphology, and laser fluence.