1. School of Chemistry, Sun Yat-Sen University, Guangzhou, Guangdong 510006, P. R. China
2. Sinopec Maoming Petrochemical Co., Ltd., Maoming, Guangdong 525000, P. R. China
3. Key Laboratory of Tobacco Flavor Basic Research, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, Henan 450001, P. R. China