PRELIMINARY GAS HUB FOR DETECTION DEVICE

摘要

IMS apparatus has a pre-concentrator (9) in its inlet (7). A pressure pulser (8) connected to the interior of the housing (1) applies small alternating negative and positive pressure pulses to the housing so that air is drawn in and out of the inlet (7) in a panting fashion. This causes analyte to be adsorbed by the pre-concentrator (9) but does not allow analyte to enter sufficiently to be ionized and detected. After a time sufficient to accumulate a detectable amount of analyte on the pre-concentrator (9) the apparatus switches to a desorb phase. The pre-concentrator (9) is heated to desorb the analyte and the pulser (8) produces a larger negative pulse sufficient to draw the liberated analyte far enough into the reaction region (3) for ionization and detection.