Mass spectral chemical fingerprints reveal the molecular dependence of exhaust particulate matters on engine speeds  

作　　者：Yi Li Hua Zhang Zongshan Zhao Yong Tian Kun Liu Feifan Jie Liang Zhu Huanwen Chen 

机构地区：[1]Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology [2]CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

出　　处：《Journal of Environmental Sciences》2018年第5期287-293,共7页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 21675021, 21607161, 21520102007);the Program for Changjiang Scholars and Innovative Research Team in Universities (PCSIRT) (No. IRT 13054);the Science and Technology Planning Project at the Ministry of Science and Technology of Jiangxi Province, China (No. 20152ACH80010);Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation Open Foundation (No. JXMS201501, JXMS201516)

摘　　要：Particulate matters（PMs） emitted by automobile exhaust contribute to a significant fraction of the global PMs. Extractive atmospheric pressure chemical ionization mass spectrometry（EAPCI-MS） was developed to explore the molecular dependence of PMs collected from exhaust gases produced at different vehicle engine speeds. The mass spectral fingerprints of the organic compounds embedded in differentially sized PMs（e.g., 0.22–0.45, 0.45–1.00, 1.00–2.00, 2.00–3.00, 3.00–5.00, and 5.00–10.00 μm） generated at different engine speeds（e.g., 1000, 1500, 2000, 2500, and 3000 r/min） were chemically profiled in the mass range of mass to charge ratio（m/z） 50–800. Organic compounds,including alcohols, aldehydes, and esters, were detected in all the PMs tested, with varied concentration levels for each individual PM sample. At relatively low engine speeds（≤ 1500 r/min）, the total amount of organic species embedded in PMs of 0.22–1.00 μm was greater than in PMs of other sizes, while more organic species were found in PMs of5.00–10.00 μm at high engine speeds（≥ 3000 r/min）, indicating that the organic compounds distributed in different sizes of PMs strongly correlated with the engine speed. The experimental data showed that the EAPCI-MS technique enables molecular characterization of PMs in exhaust, revealing the chemical dependence of PMs on the engine speeds（i.e., the combustion conditions） of automobiles.Particulate matters（PMs） emitted by automobile exhaust contribute to a significant fraction of the global PMs. Extractive atmospheric pressure chemical ionization mass spectrometry（EAPCI-MS） was developed to explore the molecular dependence of PMs collected from exhaust gases produced at different vehicle engine speeds. The mass spectral fingerprints of the organic compounds embedded in differentially sized PMs（e.g., 0.22–0.45, 0.45–1.00, 1.00–2.00, 2.00–3.00, 3.00–5.00, and 5.00–10.00 μm） generated at different engine speeds（e.g., 1000, 1500, 2000, 2500, and 3000 r/min） were chemically profiled in the mass range of mass to charge ratio（m/z） 50–800. Organic compounds,including alcohols, aldehydes, and esters, were detected in all the PMs tested, with varied concentration levels for each individual PM sample. At relatively low engine speeds（≤ 1500 r/min）, the total amount of organic species embedded in PMs of 0.22–1.00 μm was greater than in PMs of other sizes, while more organic species were found in PMs of5.00–10.00 μm at high engine speeds（≥ 3000 r/min）, indicating that the organic compounds distributed in different sizes of PMs strongly correlated with the engine speed. The experimental data showed that the EAPCI-MS technique enables molecular characterization of PMs in exhaust, revealing the chemical dependence of PMs on the engine speeds（i.e., the combustion conditions） of automobiles.

关 键 词：Exhaust particulate matters Engine speeds Mass spectral Chemical fingerprints 

分 类 号：O657.63[理学—分析化学] U464.134.4[理学—化学] X734.2[机械工程—车辆工程]