Zhu Y J, Olson N, Beebe T P
Department of Chemistry and Surface Analysis Facility, University of Utah, Salt Lake City 84112, USA.
Environ Sci Technol. 2001 Aug 1;35(15):3113-21. doi: 10.1021/es0019530.
Particulate matter with a diameter of 2.5 microm collected in Salt Lake City (SLC PM2.5) was studied using TOF-SIMS (time-of-flight secondary-ion mass spectrometry), XPS (X-ray photoelectron spectroscopy), and FTIR (Fourier transform infrared spectroscopy). The high spatial resolution and high surface sensitivity of TOF-SIMS allow the surfaces of individual particulates to be analyzed. The high mass-resolution of TOF-SIMS provides good separation of signals from different chemical species at the same nominal mass, and the extremely high detection sensitivity of TOF-SIMS makes the detection of trace elements possible. Metallic elements such as Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Cu, Zn, Cs, and Bi were detected by TOF-SIMS on the surface of SLC PM25. The uranium ion U+ together with its oxide ions UO+ and UO2+ were also found. Inorganic compounds detected include oxides, hydroxides, nitrates, sulfates, silicates, borates, chlorides, etc. Organic compounds detected include hydrocarbons, alcohols, aldehydes, ethers, carboxylic acids, amines, amides, nitriles, etc. A number of polycyclic aromatic hydrocarbons (PAH) and nitrated polycyclic aromatic hydrocarbons were detected by TOF-SIMS. High-resolution XPS Cls spectrum shows functional groups such as C-O, CO2, C-CO2, C-C, and C-H and aromatic pi-pi* shake-up transitions. High-resolution XPS O 1s spectrum indicates the coexistence of different oxygen compounds on the surface of PM2.5. FTIR results confirm the presence of various organic compounds in SLC PM2.5 detected by TOF-SIMS and XPS.
利用飞行时间二次离子质谱（TOF-SIMS）、X射线光电子能谱（XPS）和傅里叶变换红外光谱（FTIR）对在盐湖城采集的直径为2.5微米的颗粒物（SLC PM2.5）进行了研究。TOF-SIMS的高空间分辨率和高表面灵敏度使得能够对单个颗粒物的表面进行分析。TOF-SIMS的高质量分辨率能够在相同标称质量下很好地分离来自不同化学物种的信号，并且其极高的检测灵敏度使得痕量元素的检测成为可能。通过TOF-SIMS在SLC PM2.5表面检测到了锂、钠、镁、铝、钾、钙、铬、锰、铁、铜、锌、铯和铋等金属元素。还发现了铀离子U⁺及其氧化物离子UO⁺和UO₂⁺。检测到的无机化合物包括氧化物、氢氧化物、硝酸盐、硫酸盐、硅酸盐、硼酸盐、氯化物等。检测到的有机化合物包括碳氢化合物、醇类、醛类、醚类、羧酸、胺类、酰胺类、腈类等。通过TOF-SIMS检测到了多种多环芳烃（PAH）和硝化多环芳烃。高分辨率XPS Cls光谱显示了诸如C-O、CO₂、C-CO₂、C-C和C-H等官能团以及芳香π-π*振激跃迁。高分辨率XPS O 1s光谱表明在PM2.5表面存在不同的含氧化合物。FTIR结果证实了通过TOF-SIMS和XPS检测到的SLC PM2.5中存在各种有机化合物。
