Infrared Reflectance Spectroscopic Evaluation of Inkjet Printed Standards of Cyclotrimethylenetrinitramine (RDX) on Aluminum Substrates

The Department of Defense (DOD) and first responder communities are evaluating and developing optical systems for the detection and identification of explosives and components used for assembling homemade explosives (HMEs). Emerging detection technologies must be evaluated with authentic hazard material concentrations to ensure their accurate and reliable use in the field. In this work, infrared (IR) reflectance spectra over the spectral rage of 1000–1700 cm–1 were collected for different concentrations of inkjet-printed RDX (cyclotrimethylenetrinitramine) samples deposited onto aluminum substrates. A plot of the integrated area of both the symmetric and asymmetric NO2 vibrational bands for RDX on aluminum exhibited good linearity over the concentration range 20–500 µg/cm2. Detection limits for RDX on an aluminum surface were calculated to be 10.7 µg/cm2 for the symmetric NO2 vibrational band and 1.4 µg/cm2 for the asymmetric NO2 vibrational band. Evaluation of the NO2 vibrational band areas at different ...