RESEARCH ARTICLE Vibrating tip spray ionization mass spectrometry for direct sample analysis Ya‐Nan Yao Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for Online Source Apportionment System of Air Pollution, Jinan University, Guangzhou, 510632 China Search for more papers by this author Lin Wu Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for Online Source Apportionment...