Preparation of data base for the determination and estimation of high explosives and a comparative study of different methods of estimation of RDX

Abstract

Analysis of post explosion residues containing high explosive and quick disposal of cases require a suitable analytical data base in the laboratory for the rapid detection and estimation of explosives In the residues. GC-MS is found to be appropriate for the separation, detection and estimation of explosives and a suitable data base for the detection and estimation of high explosives is presented. RDX has been found to be one of the main constituents of the explosives. Depending on the availability of RDX in the post explosion residues, suitable analytical method Is needed for its detection and estimation. A comparative study of the different methods of detection and quantitation of RDX using UV-Vis, FTIR, GC-MS, HPLC and HPTLC instruments has been made for proper selection of the analytical method. The range of detection and estimation of RDX is 100 μg - 1 ng or less depending on the method used. Two chromogenic agents tryptophan and chromotropic acid used for the detection of CH 2 O and RDX (which decompose to 3CH 2 Ο in presence of strong H 2 SO 4 ) were examined for the quantitation of CH 2 O and traces of RDX. Formaldehyde in presence of H 2 SO 4 and traces of FeCl 3 solution reacts with tryptophan to form a red colored complex with absorption maximum at 451 nm. Similarly, CH 2 O (RDX) reacts with chromotropic acid in 16 N H 2 SO 4 to form a blue-violet colored complex with an absorption maximum at 577 nm. However, CH 2 O can be completely converted into the complex with large excess of tryptophan or chromotropic acid and the extinction coefficients of the complex are utilized for the quantitation of CH 2 O or RDX. The stability constant of the complex at 298 K between CH 2 O and chromotropic acid has been determined.