| 摘要 |
IMS apparatus has a preconcentrator (7) outside its inlet aperture (6). Analyte vapour is adsorbed during a first phase when substantially no gas is admitted to the reaction region (3). The preconcentrator (7) is then energised to desorb the analyte molecules and create a volume of desorbed molecules outsde the IMS housing (1). Next, a pressure pulser (8) is energised momentarily to drop pressure in the housing (1) and draw in a small sip of the analyte molecules from the desorbed volume (9) through the aperture (6). This is repeated until the concentration of analyte molecules in the desorbed volume (9) is too low for accurate analysis, following which the apparatus enters another adsorption phase. |
