Non-contact trace chemical screening

Abstract

Methods and devices for detecting a target substance on a subject without contacting the subject are disclosed. At least one air jet blows analyte from a surface of the subject into an airflow, the airflow entraining the analyte. A desorption channel desorbs molecules from analyte in a portion of the airflow travelling through the desorption channel. An ionizer forms ions from vapour molecules in the portion of the airflow. At least one mass spectrometer analyzes the ions to detect the target substance. The airflow travels without interruption from the subject to the at least one mass spectrometer. The desorption channel causes a sufficient quantity of molecules to desorb from the analyte to enable the at least one mass spectrometer to detect the target substance.

What is claimed is: 
     
         1 . A device for detecting a target substance on a subject without contacting said subject, said device comprising:
 at least one air jet for blowing analyte from a surface of said subject into an airflow, said airflow entraining said analyte;   a desorber comprising:
 an inlet for receiving at least a portion of said airflow including entrained analyte; 
 a desorption channel in fluid communication with said inlet for desorbing molecules from analyte entrained in said portion of said airflow received by way of said inlet, and travelling through said desorption channel; 
   an ionizer, in fluid communication with said desorption channel, for forming ions from vapour molecules in said portion of said airflow;   at least one mass spectrometer in fluid communication with said ionizer, for analyzing said ions to detect said target substance;   wherein said airflow travels without interruption from said subject to said at least one mass spectrometer; and   wherein said desorption channel causes a sufficient quantity of molecules to desorb from said analyte to enable said at least one mass spectrometer to detect said target substance.