EnviroMail™28/Europe: Modern analytical methods for tracing explosives in the environment

Explosive compounds represent an important group of environmental pollutants primarily introduced into ecosystems through military activities, manufacturing, storage, or disposal of munitions. Their presence in soil and water poses significant risks to both ecosystems and human health. Certain compounds, such as hexogen (RDX) and 2,4-dinitrotoluene (2,4-DNT), are even classified as potential carcinogens. Consequently, monitoring, analytical determination, and devising strategies for the effective removal of explosives and their residues from the environment are critical for minimizing associated risks efficiently.

ALS Czech Republic: Figure 1: Illustrative picture

Explosives in the Environment

In 2025, the ALS laboratory expanded its analytical portfolio to include accredited methods for the determination of explosives and related compounds in water and soil. These procedures are based on internationally recognized standards such as US EPA 8330B, EN ISO 22478, and ISO 11916-1.

Developing effective strategies to detect and remediate explosives contamination in environmental samples, particularly in testing regions, is crucial, as current methods depend on limited data regarding explosives and their environmental impacts. Commonly used explosive compounds, such as nitroaromatics and nitramines, pose a relatively high risk of environmental contamination, while nitramines are highly mobile. Despite their reactivity, these substances are relatively stable in nature under normal conditions. TNT, for example, can persist in soil for decades, particularly in areas with limited oxygen access and low microbial activity.

A significant example of long-term contamination is the Kolberger Heide area in the Baltic Sea, where munitions were extensively dumped after World War II. A 2025 study confirmed the presence of TNT metabolites in the urine and bile of fish, indicating the bioaccumulation of explosive substances in marine organisms and their persistence in the environment for over eight decades.

ALS Czech Republic: Figure 2: TNT formula (2,4,6-Trinitrotoluene) and Figure 3: RDX/Hexogen formula (Hexahydro-1,3,5-trinitro-1,3,- 5-triazine)

Analysis of Explosives

The implementation of accurate analytical methods enables the reliable identification and quantification of a wide range of explosive substances, including their degradation products, antioxidants, and propellants. The introduction of such methods reflects the growing need to monitor these contaminants from both civilian and military sources.

The U.S. Environmental Protection Agency (EPA) uses Method 8330B (SW-846) for the analysis of nitroaromatics, nitramines, and nitrate esters using HPLC, a standardized method that ensures precise analytical results. 

In ALS, sample handling and preparation adhere to procedures outlined by applicable standards, and the analyses are conducted on state-of-the-art HPLC-DAD systems of the latest generation. Each positive finding is initially verified based on spectral matching and subsequently confirmed using an alternative stationary phase of the chromatographic column. This approach ensures high reliability of the measured data.

List of target analytes for their determination in water and soil

• Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine — HMX / Oktogen; CAS: 2691-41-0; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• Hexahydro-1,3,5-trinitro-1,3,5-triazine — RDX / Hexogen; CAS: 121-82-4; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 1,3,5-Trinitrobenzene — 1,3,5-TNB; CAS: 99-35-4; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 1,3-Dinitrobenzene — 1,3-DNB; CAS: 99-65-0; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• Methyl-2,4,6-trinitrophenyl-nitramine — Tetryl / CE; CAS: 479-45-8; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• Nitrobenzene — NB; CAS: 98-95-3; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 2,4,6-Trinitrotoluene — 2,4,6-TNT; CAS: 118-96-7; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 4-Amino-2,6-dinitrotoluene — 4-Am-DNT; CAS: 19406-51-0; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 2-Amino-4,6-dinitrotoluene — 2-Am-DNT; CAS: 35572-78-2; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 2,4-Dinitrotoluene — 2,4-DNT; CAS: 121-14-2; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 2,6-Dinitrotoluene — 2,6-DNT; CAS: 606-20-2; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 2-Nitrotoluene — 2-NT; CAS: 88-72-2; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 3-Nitrotoluene — 3-NT; CAS: 99-08-1; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• 4-Nitrotoluene — 4-NT; CAS: 99-99-0; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• Nitroglycerin (glycerol trinitrate) — NG; CAS: 55-63-0; LOR soil: 1 mg/kg; LOR water: 1 µg/L
• Pentaerythritol tetranitrate — PETN; CAS: 78-11-5; LOR soil: 1 mg/kg; LOR water: 1 µg/L
• 3,5-Dinitroaniline — 3,5-DNA; CAS: 618-87-1; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• Diphenylamine — DPA / Dpha; CAS: 122-39-4; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L
• N-nitrosodiphenylamine — NDPhA; CAS: 86-30-6; LOR soil: 0.2 mg/kg; LOR water: 0.4 µg/L

First Experimental Testing

Initial results from the ALS laboratory indicate potential positive detections of hexogen (RDX) in the analyzed samples, with concentrations in aqueous samples reaching up to tens of μg/L, and soil samples showing values in the range of single-digit mg/kg (of original sample).

Although there are currently no legislative requirements for systematic monitoring of explosive substances in the environment, increased awareness and understanding of these substances are driving legislative changes. For example, in 2020, Canada mandated the monitoring of hexogen (RDX) in waters used for drinking water production, setting a limit of 100 μg/L due to positive findings of RDX in surface and groundwater near military bases.

The implementation of new accredited methods according to international standards represents a crucial step towards effective monitoring of explosive substances in the environment. The results confirm the presence of these pollutants in soils and waters and underscore the necessity for their systematic tracking. The data obtained are essential not only for assessing environmental risks but also for designing appropriate remediation measures.

ALS Czech Republic: Figure 5: Analytes Chromatogram Example: (10 μg/mL mixed standard): (1) HMX; (2) RDX; (3) 1,3,5-Trinitrobenzene; (4) 1,2-Dinitrobenzene; (5) 1,3-Dinitrobenzene; (6) 3,5-Dinitroaniline; (7) Tetryl; (8) Nitrobenzene; (9) Nitroglycerin; (10) 2,4,6-Trinitrotoluene; (11) 4-Amino-2,6 -Dinitrotoluene; (12) 2-Amino-4,6-Dinitrotoluene; (13) 2,6-Dinitrotoluene; (14) 2,4-Dinitrotoluene; (15) 2-Nitrotoluene; (16) 4-Nitrotoluene; (17) 3-Nitrotoluene; (18) PETN; (19) N-nitrosodiphenylamine; (20) Diphenylamine.

Sample Requirements

• Water: ideally 2 L of sediment-free sample, dark glass sampler
• Soil: ideally 200 g sample, plastic container (bag/cup – Fig.4)

Sampling container note: water samples must be collected and transported only in dark glass bottles to prevent potential photodegradation of target analytes caused by light exposure due to water transparency. Soil samples do not require such protection as they are not similarly affected.

ALS Czech Republic: Figure 4: Polypropylene container for solid soil sampling. In case you are interested in explosive analysis, please contact us and the container will be delivered to you.

Time of Analysis (TAT)

• Results of explosives determination will be delivered within 10–14 days depending on the type of matrix.
• Express analysis: not possible due to sample processing.

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