Aerosol time-of-fl ight mass spectrometer for measuring ultra fi ne aerosol particles
Aerosol time-of-fl ight mass spectrometer for measuring ultra fi ne aerosol particles
复制标题
用于测量超细气溶胶颗粒的气溶胶飞行时间质谱仪
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Riekkola
中科院分区：
文献类型：
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作者：
T. Laitinen;K. Hartonen;M. Kulmala;M. Riekkola
本文介绍了一台用于测量超细气溶胶粒子的气溶胶质谱仪。该设备的操作基于在短时间内将气溶胶颗粒收集到金属表面上。近实时的气溶胶颗粒收集使得分析具有短寿命的颗粒相化合物成为可能。收集的气溶胶颗粒用双极充电器充电，通过微分迁移率分析仪根据其电迁移率进行尺寸分离，并通过静电沉积在采样阀的带电金属表面上进行收集。在质谱分析之前，对收集的颗粒进行两步激光解吸电离。离子化的分子根据它们的m/z比进行分析，并用微通道板检测器进行检测。用不同的化合物对气溶胶质谱仪进行了校准，并研究了其对选定有机化合物测定的适用性。质量轴的校准显示出良好的相关性（R = 0.9996）。在次皮克浓度下获得了超细环境气溶胶颗粒的质谱数据。
An aerosol mass spectrometer for ultrafi ne aerosol particles was constructed. The operation of the apparatus is based on the aerosol particle collection onto a metal surface over a short period. The near real-time aerosol particle collection makes possible an analysis of the particle phase compounds with short lifetimes. The collected aerosol particles are charged with a bipolar charger, size-separated by a differential mobility analyzer according to their electrical mobility and collected via electrostatic deposition on the electrically charged metal surface of a sampling valve. The collected particles are subjected to a two-step laser desorption ionization before the mass spectrometric analysis. The ionized molecules are analyzed according to their m/z ratios and detected with a micro-channel plate detector. The aerosol mass spectrometer was calibrated with different chemical compounds, and its applicability for the determination of selected organic compounds was studied. The calibration of the mass axis showed a good correlation (R = 0.9996). Mass spectral data for ultrafi ne ambient aerosol particles was obtained at sub-picogram concentrations.