Volume 38, Issue 4 (July 1993)
Investigations of Thin Layer Chromatographic Techniques Used for Forensic Explosives Analysis in the Early 1970s
The article describes three brief experimental studies of the thin layer chromatographic (TLC) techniques used for forensic explosive investigations at Royal Armament Research and Development Establishment at Woolwich (RARDE Woolwich) in 1974. The first study demonstrated that 200 ng amounts of nitroglycerine (NG) and pentaerythritol tetranitrate (PETN) in TLC spots visualized using the sodium hydroxide/Griess system can be recovered and reanalyzed using a second TLC eluent. In the second study the characteristics of a titanium(III) chloride/4-dimethylaminobenzaldehyde visualization system for nitrotoluenes were investigated. In the third study it was shown that under certain conditions the rate of PETN spot color development after Griess reagent spray could be very slow in comparison with that of NG.