| 摘要 |
<p>IMS apparatus has a preconcentrator in an inlet passage. A pressure pulser connected to the interior of a housing applies small alternating negative and positive pressure pulses to the housing so that air is drawn in and out of the inlet passage in a“panting”fashion. This causes analyte to be adsorbed by the preconcentrator 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 preconcentrator the apparatus switches to a desorb phase. The preconcentrator is heated to desorb the analyte, and the pressure pulser produces a larger negative pulse sufficient to draw the liberated analyte far enough into the reaction region for ionization and detection.</p> |
