Abstract

A sensitive, specific and simple color test for the improvised explosive urea nitrate is described. It is based on the formation of a red pigment upon the reaction between urea nitrate and p-dimethylaminocinnamaldehyde (p-DMAC) under neutral conditions. Urea itself, which is the starting material for urea nitrate, does not react with p-DMAC under the same conditions. Other potential sources of false positive response e.g., common fertilizers, medications containing the urea moiety and various amines, do not produce the red pigment with p-DMAC. Exhibits collected from 10 terrorist cases have been tested with p-DMAC. The results were in full agreement with those obtained by instrumental techniques including GC/MS, XRD and IR.

Issue Section:
Technical Notes
Keywords:
forensic science, field test, explosives, urea nitrate, color test, p-dimethylaminocinnamaldehyde (p-DMAC), p-dimethylaminobenzaldehyde (p-DMAB)

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