An explosive detection screening system used for the detection of explosives and other controlled substances such as drugs or narcotics. The screening system detects the relatively volatile and non-volatile vapors and/or particulate matter emissions from the aforementioned substances and reports that they are present on an individual or object and the concentration of each substance detected. The screening system comprises a sampling chamber for the collection of the vapor and/or particulate emissions, a concentration and analyzing system for the purification of the collected vapor and/or particulate emissions and subsequent detailed chemical analysis of the emissions, and a control and data processing system for the control of the overall system.