Abstrakt
Selected ion flow tube mass spectrometry (SIFT-MS) is an analytical technique for real time qualification and quantification of a great variety of organic and inorganic volatile compounds in the range of concentrations down to the part per billion by volume. SIFT-MS technique is based on ion-molecule reactions in the flow tube between selected reagent ions and neutral analyte molecules present in the sample.
Product ions of these reactions are analysed by a quadrupole mass spectrometer. However, one current shortcoming is a lack of ability to distinguish organic compounds that lead to product ions with equal mass even when their molecular structures are different.
In order to separate them, an electric field could be used as the ion mobility depends on the geometry and size of the molecular ion. It is thus proposed to extend SIFT-MS with an ion mobility stage and thus to develop selected ion mobility mass spectrometry technique (SIM-MS).
We present the proposed concept of this technique together with the first results obtained using a newly constructed instrument.