As an unbreachable personnel identification system, we propose to couple a vapor collector to a mass spectrometer in order to profile human vapor "signatures." These profiles of chemically complex "signatures" will then be compared to a references file using a highly effective pattern matching algorithm. Phase I effort will demonstrate the existence of these "signatures" and show that existing instrumentation has almost sufficient sensitivity and specifically to detect and distinguished between them. In Phase II a practical system having the required capabilities will be constructed by refining and updating currently available technology. This system will then be used to determine the parameters and constancy of the identifying chemical "signatures" and to discover what differentiates each from all others. These data will be used to devise an algorithm that will automatically determine and store the unique aspects of the mass spectrum of each signature. In order to achieve rapid and accurate personnel identification, the system will compare features in a mass spectrum of the chemical vapors emanating from an individual with corresponding aspects in a library file of unique chemical "signatures." The degree of match which is necessary for a positive identification will be established.
