A technique is described for the analysis of the plastic explosive, C-4. The method involves a chloroform extraction of the sample and an infrared examination of the extract. Problems that may be encountered in attempting to identify C-4 are discussed and solutions to these problems are proposed.

Infrared absorption spectrophotometry with a diamond cell sample holder is routinely employed in our laboratory for the examination of plastic wire insulation. The determination of the type of polymer used as insulation on electric blasting cap leg wire allows the manufacturer of the cap to be identified [1].