Modern analytical methods for tracing explosives in the environment

Significance of the Topic

Explosive residues such as RDX, TNT and 2,4-DNT are persistent environmental pollutants originating from military operations, industrial manufacturing, storage and disposal of munitions. Their stability under typical soil and water conditions and potential carcinogenicity pose long-term risks to ecosystems and human health. Effective monitoring and remediation strategies are essential to identify contamination hotspots, assess exposure pathways and guide risk management.

Study Objectives and Overview

This report reviews the introduction and validation of accredited analytical methods for quantifying a broad spectrum of explosive compounds in soil and water. Key goals include:

• Implementing internationally recognized standards (US EPA 8330B; EN ISO 22478; ISO 11916-1) for explosives analysis.
• Expanding laboratory capabilities to detect nitroaromatics, nitramines and nitrate esters at environmentally relevant limits.
• Demonstrating method reliability through initial field and laboratory testing.

Methodology and Instrumentation

Sample handling followed strict protocols to prevent contamination and photodegradation. Soil samples (≈200 g) were collected in polypropylene containers; water samples (2 L) were transported in dark glass bottles. Extraction and cleanup steps adhered to standard procedures. Analytical separation and detection were achieved using high-performance liquid chromatography with diode-array detection (HPLC-DAD). Positive analyte identifications were confirmed by spectral matching and alternative stationary phases.

Used Instrumentation

• HPLC-DAD system (latest generation) for separation and quantification.
• Chromatographic columns with dual stationary phases for confirmation analyses.
• Dark glass sampling bottles and polypropylene soil containers to preserve sample integrity.

Key Findings and Discussion

Initial tests detected RDX in water at up to tens of micrograms per liter and in soil at single-digit milligrams per kilogram. The method achieved limits of reporting around 0.2 mg/kg in soil and 0.4 µg/L in water for most nitroaromatic and nitramine targets. Persistent TNT metabolites have been documented to bioaccumulate in marine organisms decades after disposal events. Legislative drivers, such as Canada’s RDX limit of 100 µg/L in drinking-water sources, underscore the need for routine surveillance.

Benefits and Practical Applications

• High analytical sensitivity enables early detection of low-level contamination.
• Standardized protocols support regulatory compliance and inter-laboratory comparability.
• Data inform environmental risk assessments and guide remediation design.

Future Trends and Opportunities

Emerging avenues include coupling HPLC to high-resolution mass spectrometry for greater specificity, deploying in situ sensor technologies for real-time monitoring, and expanding libraries of degradation products. Increased regulatory focus on explosive residues will drive method miniaturization, automation and integration with geographic information systems for spatial mapping of contamination.

Conclusion

The adoption of internationally accredited HPLC-DAD methods for a comprehensive suite of explosives marks a critical advance in environmental analytics. Demonstrated reliability at low detection limits and early positive findings of RDX emphasize the importance of systematic monitoring. Continued method refinement and legislative support will enhance our capacity to protect ecosystems and public health.

Reference

• Brinkman, U. A. T., & Dubs, M. (2013). Tracking explosive contaminants from dumped munitions in the western Baltic Sea via urine and bile analysis of three flatfish species. Environmental Science & Technology, 47(15), 8478–8485.
• Stigzelius, S. H., et al. (2020). Sea-dumped munitions in the Baltic Sea support high epifauna abundance and diversity. Marine Pollution Bulletin, 151, 110812.
• US EPA. (2012). Technical Fact Sheet – Dinitrotoluene (DNT). Washington, DC: United States Environmental Protection Agency.