Processing of Training Range Soils for the Analysis of Energetic Compounds
Abstract
Large soil samples are often necessary to represent areas where analytes are distributed as particulates. Proper processing of these large samples impose additional time, space, and equipment requirements on the laboratory community servicing environmental programs to investigate military training ranges. Part of this study evaluated the robustness of two methods used to process large soil samples for the determination of energetic munitions residues whole sample mechanical grinding (comminution) and solvent dissolution. Both methods have been used successfully to reduce subsampling variance for samples collected on training ranges where particles of energetic residues have accumulated. However, two energetic compounds frequently detected in such samples nitroglycerin (NG) and 2,4-dinitrotoluene (2,4-DNT) may be susceptible to evaporative losses during solvent dissolution. Robustness experiments involved both lab-spiked and field-collected soils with various concentrations of energetic residue. An experiment utilizing field-collected soils involved the use of a rotary splitter. Even with this highly regarded equipment, the samples could not be split consistently, preventing a direct comparison of the two techniques in soils with residue concentrations less than 40 mg/kg. Two other investigations evaluated sample holding times and cross-contamination resulting from grinding processes. The results indicated that energetic compounds typically found on military training ranges were stable in air-dried soils for periods in excess of 53 days when stored in the dark at room temperature. A slight amount of cross contamination from grinding was detectable using gas chromatography. The concentrations were below detectable levels when using liquid chromatography and were eliminated by adding a step of soaking the grinding bowl in a sonic bath filled with dilute cleaning detergent to the cleaning protocol.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2007
- Accession Number
- ADA472096
Entities
People
- Alan Hewitt
- Dennis Lambert
- Kevin Bjella
- Marianne Walsh
- Susan Bigl
- Sylvie Brochu