Pulsed Admission of Analyte to Detection Apparatus

摘要

A detecting method using an IMS apparatus with a preconcentrator outside its inlet aperture. Analyte vapor is adsorbed during a first phase when substantially no gas is admitted to the reaction region. The preconcentrator is then energized to desorb the analyte molecules and create a volume of desorbed molecules outside the IMS housing. Next, a pressure pulser is energized momentarily to drop pressure in the housing and draw in a small sip of the analyte molecules from the desorbed volume through the aperture. This is repeated until the concentration of analyte molecules in the desorbed volume is too low for accurate analysis, following which the apparatus enters another adsorption phase.

主权项

1. A method of detecting or analyzing an analyte sample gas or vapor, comprising the steps of:
establishing a volume of analyte; admitting bursts of analyte molecules less than the established volume to a reaction region, the bursts being separated by periods of time during which substantially no analyte molecules are admitted; and detecting the presence of the admitted analyte molecules.