Recirculating filtration system for use with a transportable ion mobility spectrometer

摘要

Generally, the present invention provides a recirculating filtration system for use with a transportable ion mobility spectrometer. A first preferred embodiment of the transportable recirculating filtration system comprises a pump connected with a set of filters and flow sensors to an IMS sensor. The IMS sensor's outlet flow is cleaned by the filters and recirculated by the pump back into the IMS sensor as the carrier fluid stream flow. A portion of the IMS sensor's outlet flow equal to the amount of flow introduced into the sensor is exhausted from the filtration system to maintain a constant total flow volume through the system as the sample is being taken. A second preferred embodiment of the present invention provides a transportable recirculating filtration system for measuring an unknown concentration of a selected ionizable contaminant substance such as benzene present in which other substances may coexist, which employs a device for introducing a controlled concentration of the selected ionizable contaminant into an ion mobility spectrometry (IMS) sensor. The unknown concentration is calculated using the Standard Addition Method. The second preferred embodiment of the present invention can also be used to calibrate the IMS sensor by establishing which ionogram structures result from the presence of a particular analyte in the sample stream. A third preferred embodiment of the present invention provides a recirculating filtration system for use with a transportable ion mobility spectrometer in gas chromatography applications. The transportable recirculating filtration system comprises a pump and a set of filters and flow sensors connected to an ion mobility spectrometry sensor having a gas chromatograph column at its inlet.