2P-25 PDF
Fundamental Principle of Selected Ion Flow Tube Mass Spectrometer (SIFT-MS) and Examples of Real-time Measuring Volatile Components
Selected Ion Flow Tube Mass Spectrometer (SIFT-MS) is a kind of chemical ionization (CI) mass spectrometer. It has three reagent ions (H3O+, NO+ and O2+) which enable it to produce three separate mass spectra. The three reagent ions have different ion-molecule chemistry (H3O+: proton transfer (PT) and association; NO+: charge transfer (CT), dissociative CT, association and hydride abstraction; O2+: CT, dissociative CT and hydride abstraction). These multiple reaction mechanisms are extremely important to seek maximum selectivity because it provides three different types of independent “mass spectral fingerprints”.