Identification of explosives and constituents of fuel oil in ANFO using HPTLC and GC-MS technique

Central Forensic Science Laboratory, 30, Gorachand Road, Kolkata-700 014, India
E-mail : kuiladk@rediffmail.com
Kalyani Government Engineering College, Kalyani-741 235, West Bengal, India
E-mail : sujitclahiri@yahoo.com
Manuscript received 21 August 2006, accepted 7 November 2006

ANFO (a mixture of NH₄NO₃ + 5-6% fuel oil), the dominant explosive used by the blasting industry can
easily be smuggled from the source or can be prepared easily. Most of the blasting incidents in West Bengal were found to be due to low cost explosive ANFO (of NH₄NO₃ + 5-6% fuel oil) as evidenced from chemical analysis. ANFO is a low cost explosive and can be triggered by any modern triggering mechanisms by the criminals. The residues collected from the crime spot and the explosives where subjected to test for ammonium ion, nitrate ion and fuel oils. However, high explosives like TNT, RDX, PETN etc. were absent.

HPTLC techniques were adopted with the new efficient solvent system Rosallac thinner and acetone mixture in the ratio (1 : 3) for the separation and identification of heavier hydrocarbons in the fuel oil as a whole. GC/MS technique was also used to confirm the presence of various constituents of fuel oil.