Abstract

Background: Post-blast residue (PBR) analysis in soil is crucial for forensic investigations to reconstruct explosive events and establish crime scene linkages. Advanced analytical techniques enhance residue detection reliability.  Objective: To evaluate the occurrence and distribution of post-blast inorganic explosive residues in soil samples and assess the effectiveness of complementary analytical techniques.  Methods: One hundred post-blast soil samples collected from blast crater, near-blast, peripheral and control locations were analyzed using ion chromatography (IC), FTIR spectroscopy, GC–MS and SEM–EDS. Comparative analyses were performed between blast-associated and control samples (P<0.05).  Results: Samples were distributed across crater (40.0%), near-blast (30.0%), peripheral (20.0%) and control (10.0%) zones. Nitrate was most frequently detected (72.0%, mean 18.6±6.3 mg/kg), followed by ammonium (51.0%), nitrite (38.0%), chlorate (29.0%) and perchlorate (11.0%). Ion chromatography showed the highest confirmation rate (72.0%), followed by FTIR (58.0%), GC–MS (46.0%) and SEM–EDS (41.0%). Residue concentrations were significantly higher in blast-associated soil than controls (P<0.05), with maximum detection in crater samples (92.5%) that decreased progressively with distance (P<0.001). Conclusion: Integrated analytical techniques effectively support forensic identification of post-blast residues in soil samples. Combining ion chromatography with complementary spectroscopic and microscopic methods enhances analytical confidence and assists in crime-scene reconstruction. Comparative soil analysis remains a key component of forensic interpretation.

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