title: High-Pressure Photon Ionization Source for TOFMS and Its Application for Online Breath Analysis.
abstract: Photon ionization mass spectrometry (PI-MS) is a widely used technique for the online detection of trace substances in complex matrices. In this work, a new high-pressure photon ionization (HPPI) ion source based on a vacuum ultraviolet (VUV) Kr lamp was developed for time-of-flight mass spectrometry (TOFMS). The detection sensitivity was improved by elevating the ion source pressure to about 700 Pa. A radio frequency (RF)-only quadrupole was employed as the ion guide system following the HPPI source to achieve high ion transmission efficiency. In-source collision induced dissociation (CID) was conducted for accurate chemical identification by varying the voltage between the ion source and the ion guide. The high humidity of the breath air can promote the detection of some compounds with higher ionization potentials (IPs) that could not be well detected by single photon ionization (SPI) at low pressure. Under 100% relative humidity (37 °C), the limits of detection down to 0.015 ppbv (parts per billion by volume) for aliphatic and aromatic hydrocarbons were obtained. This HPPI-TOFMS system was preliminarily applied for online investigations of the exhaled breath from both healthy nonsmoker and smoker subjects, demonstrating its analytical capacity for complicated gases analysis. Subsequently, several frequently reported VOCs in the breath of healthy volunteers, i.e., acetone, isoprene, 2-butanone, ethanol, acetic acid, and isopropanol, were successfully identified and quantified.
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.|University of Chinese Academy of Sciences , 19 Yuquan Road, Beijing, 100039, People's Republic of China.
authors: Yan
authors: Y
authors: Wang
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.|University of Chinese Academy of Sciences , 19 Yuquan Road, Beijing, 100039, People's Republic of China.
authors: Jichun
authors: J
authors: Jiang
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.
authors: Lei
authors: L
authors: Hua
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.
authors: Keyong
authors: K
authors: Hou
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.
authors: Yuanyuan
authors: Y
authors: Xie
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.
authors: Ping
authors: P
authors: Chen
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.|University of Chinese Academy of Sciences , 19 Yuquan Road, Beijing, 100039, People's Republic of China.
authors: Wei
authors: W
authors: Liu
authors: Department of Instrumentation and Electrical Engineering, Jilin University , Jilin, 130021, People's Republic of China.
authors: Qingyun
authors: Q
authors: Li
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.|University of Chinese Academy of Sciences , 19 Yuquan Road, Beijing, 100039, People's Republic of China.
authors: Shuang
authors: S
authors: Wang
authors: Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , 457 Zhongshan Road, Dalian, Liaoning 116023, People's Republic of China.
authors: Haiyang
authors: H
authors: Li
mesh_terms: D001944:Breath Tests / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D045853:Exhalation; D006801:Humans; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D017785:Photons; D011312:Pressure; D014466:Ultraviolet Rays; D014618:Vacuum; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D007477:Ions; D055549:Volatile Organic Compounds