A Comparison of Trace Organic Vapor Analysis - Static SPME, Dynamic SPME, and Thermal Desorption Methods

This undergraduate project focuses on comparing sampling methods for detecting 2,3-dimethyl-2,3-dinitrobutane (DMNB), a common taggant in some commercial explosives. Solid phase microextraction (SPME), both static and dynamic, and thermal desorption from Tenax® are compared for precision (RSD) and for the limit of detection (LOD) and limit of quantitation (LOQ) using a GC/MS in the negative chemical ionization mode. The static SPME was found to be the least sensitive method, with dynamic SPME approximately 6X and thermal desorption approximately 25X more sensitive. Full details of the SPME and thermal desorption sampling techniques will be illustrated.