Cranfield University, Centre for Defence Chemistry, Defence Academy of the United Kingdom, Shrivenham SN6 7LA, UK.
Cranfield University, School of Water, Energy and Environment, Cranfield, MK43 0AL, UK.
Sci Total Environ. 2019 Jun 10;668:184-192. doi: 10.1016/j.scitotenv.2019.02.359. Epub 2019 Mar 1.
Explosive contamination is commonly found at military and manufacturing sites (Hewitt et al., 2005; Clausen et al., 2004; Walsh et al., 2013). Under current environmental legislation the extent of the contamination must be characterized by soil sampling and subsequent separation of the explosive contaminants from the soil matrix by extraction to enable chemical analysis and quantification (Dean, 2009). It is essential that the extraction method can consistently recover explosive residue from a variety of soil types i.e. all materials that have not degraded or irreversibly bound to the matrix, so that any resultant risk is not underestimated. In this study, five different soil types with a range of organic content, particle size and pH, were spiked with a mixture of RDX, DNAN, NQ and NTO at 50 mg/kg and were extracted using one of four one-step extraction methods: stirring, shaking, sonication, and accelerated solvent extraction (ASE). Analysis of the extraction efficiencies of the four methods found that they were broadly successful for the extraction of all IHE constituents from all five soils (an average of 84% ± 14% recovery across 80 extractions). However, soils with high organic content (Total Organic Content (TOC) ≥ 2%) were found to significantly affect extraction efficiency and reproducibility. NTO and DNAN were the least consistent in extraction efficiency with poorest recovery of NTO as low as 37% ± 2%. Of the four tested methods shaking was found to be the most reproducible, though less efficient than stirring (64%-91%). ASE was found to have the most variable results for extraction of IHE constituents suggesting that ASE was the most affected by the different soil types. Therefore, it is recommended that the efficiency and reproducibility of the selected extraction method should be validated by extracting known concentrations of the IHE from the soil of interest and that any required correction factors are reported.
爆炸物污染通常在军事和制造场所发现（Hewitt 等人，2005 年；Clausen 等人，2004 年；Walsh 等人，2013 年）。根据当前的环境法规，必须通过土壤采样并通过提取将爆炸物污染物与土壤基质分离来表征污染程度，以便进行化学分析和定量（Dean，2009 年）。从各种土壤类型中一致回收爆炸物残余物的提取方法至关重要，即所有未降解或不可逆地与基质结合的材料，以避免低估任何由此产生的风险。在这项研究中，五种不同的土壤类型，其有机含量、粒径和 pH 值范围广泛，用 RDX、DNAN、NQ 和 NTO 的混合物以 50mg/kg 的浓度进行了污染，并使用四种一步提取方法之一进行了提取：搅拌、摇动、超声和加速溶剂提取（ASE）。对四种方法的提取效率分析发现，它们基本上成功地从所有五种土壤中提取了所有 IHE 成分（80 次提取中平均回收率为 84%±14%）。然而，高有机含量（总有机含量（TOC）≥2%）的土壤被发现会显著影响提取效率和重现性。NTO 和 DNAN 的提取效率最不一致，NTO 的回收率最差，低至 37%±2%。在所测试的四种方法中，发现摇动法最具重现性，尽管效率低于搅拌法（64%-91%）。ASE 发现对 IHE 成分的提取结果最不稳定，表明 ASE 受不同土壤类型的影响最大。因此，建议通过从感兴趣的土壤中提取已知浓度的 IHE 来验证所选提取方法的效率和重现性，并报告任何所需的校正因子。
