1. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510 640, China
2. Institute of Mass Spectrometry and Atmospheric Environment, Jinan University, Guangzhou 510632, China
3. School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
4. School of Environmental Science and Engineering, Fudan University, 200433, Shanghai, China
5. Leibniz-Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstr. 15, 04318 Leipzig, Germany