FAIMS APPARATUS COMPRISING SOURCE OF DRY GAS

摘要

An ion mobility spectrometer has an inlet (2) opening into an ionisation region including a conventional ionisation source (4). A series of several c harged, circular electrode plates (7) with aligned apertures (8) provides a drift region (6) on the opposite side of the ionisation region from the inle t (2). A gas inlet (26) connected to a source of clean, dry flushing gas ope ns between the ends of the drift region (6), with the gas flowing against th e ion flow to one side to remove water molecules from the analyte. Gas flowi ng in the opposite direction is effective to help drive the dry analyte ions to an analysis region provided by two parallel asymmetric field plates (11) and (12).