Oral Sessions (Day1, Day2, Day3)
Poster Presentations (Day1, Day2, Day3)
Oral Sessions
- Day 3, June 24（Fri.） 15:40-16:00 Room C (411 and 412)
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3C-O2-1540 PDF
Development of an Ion Mobility Spectrometer for Breath Analysis: Theoretical Study of the Structure of Organic Ions Produced by Ambient Electron Emission Ionization
Ion Mobility Spectrometry is a promising method in breath analysis because a portable ion mobility spectrometer has the ability to detect a mixture of volatile organic compounds simultaneously in tens of milliseconds with high sensitivity. However, due to sampling in air, sample ions often form water molecule-added cluster ions, making analysis difficult. The purpose of this study is to investigate the molecular structures of ions produced by ambient electron emission ionization and theoretically predicted ion mobility spectra of breath-related organic compounds. Optimized geometries of all possible ions which were expected to be produced in the ionization chamber of the ambient electron emission ionization ion mobility spectrometer, were calculated with the DFT method using APFD/6-31++G(d,p). Collision Cross Sections of ions produced by ambient electron emission ionization were calculated in the classical trajectory method using the MOBCAL program. The calculated CCS values of [propionic acid+O2]-, [acetic acid+O2]- and [(H2O)3+O2]- were 109.3-114.1, 102.1-105.0 and 99.2-103.2 A2, respectively. The calculated drift times (Td) of [propionic acid+O2]-, [acetic acid+O2]- and [(H2O)3+O2]- were 11.6-12.1, 10.6-10.9 and 10.2-10.6 ms, respectively. These are consistent with experimental values.