Selected ion flow tube mass spectrometry (SIFT-MS) is a form of direct mass spectrometry that analyses volatile organic compounds (VOCs) in air with typical detection limits at parts-per-trillion level. Real-time, quantitative analysis is achieved by applying precisely controlled soft chemical ionization and eliminating sample preparation, pre-concentration and chromatography.
Eight chemical ionization agents (reagent ions) are applied in Syft instruments: H3O+, NO+, O2+, O–, O2–, OH–, NO2–, and NO3–. These eight reagent ions react with analyte VOCs and inorganic gases in very well controlled ion-molecule reactions, but they do not react with the major components of air (N2, O2, and Ar).
This enables SIFT-MS to analyze air at trace and ultra-trace levels without preconcentration.
Rapid switching of eight reagent ions provides unsurpassed selectivity compared to other direct MS techniques.