Nipper Marion, Qian Yaorong, Carr R Scott, Miller Karen
Center for Coastal Studies, Texas A&M University-Corpus Christi, 6300 Ocean Drive, NRC Suite 3200, Corpus Christi, TX 78412, USA.
Chemosphere. 2004 Aug;56(6):519-30. doi: 10.1016/j.chemosphere.2004.04.039.
Bio- and photo-transformation of two munitions and explosives of concern, 2,6-dinitrotoluene (2,6-DNT) and 2,4,6-trinitrophenol (picric acid) were assessed in spiked marine sediments and water. A sandy and a fine-grained sediment, with 0.25% and 1.1% total organic carbon, respectively, were used for biotransformation assessments at 10 and 20 degrees C. Sterilized sediments were used as controls for biotic vs. abiotic transformation. Transformation products were analyzed by HPLC, GC/MS and LC/MS. Biotransformation in sediments started soon after the initial contact of the chemicals with the sediments and proceeded for several months, with rates in the following sequence: fine-grain at 20 degrees C > fine-grain at 10 degrees C > sand at 20 degrees C > sand at 10 degrees C. The biotransformation paths seemed to be similar for all conditions. The major biotransformation product of 2,6-DNT was 2-amino-6-nitrotoluene (2-A-6-NT). 2-Nitrotoluene (2-NT) and other minor components, including N,N-dimethyl-3-nitroaniline, benzene nitrile, methylamino-2-nitrosophenol and diaminophenol, were also identified. After more prolonged incubation these chemicals were replaced by high molecular weight polymers. Several breakdown products of picric acid were identified by GC/MS, including 2,4-dinitrophenol, amino dinitrophenols, 3,4-diamino phenol, amino nitrophenol and nitro diaminophenol. Photo-transformation of 2,6-DNT and picric acid in seawater was assessed under simulated solar radiation (SSR). No significant photolysis of picric acid in seawater was observed for up to 47 days, but photo-transformation of 2,6-DNT began soon after the initial exposure to SSR, with 89% being photo-transformed in 24 h and none remaining after 72 h. High molecular weight chemicals were generated, with mass spectra ranging from molecular weight 200-500 compared to 182 for DNT, and the color of the stock solution changed from clear to orange. Complexity of the mass spectra and mass differences among fragments suggest that multiple polymers were produced and were co-eluting during the LC/MS analyses.
在添加了两种受关注的弹药和爆炸物（2,6 - 二硝基甲苯（2,6 - DNT）和2,4,6 - 三硝基苯酚（苦味酸））的海洋沉积物和水中，对其生物转化和光转化进行了评估。分别使用了总有机碳含量为0.25%的沙质沉积物和总有机碳含量为1.1%的细粒沉积物，在10摄氏度和20摄氏度下进行生物转化评估。经过灭菌的沉积物用作生物转化与非生物转化对比的对照。通过高效液相色谱（HPLC）、气相色谱/质谱联用仪（GC/MS）和液相色谱/质谱联用仪（LC/MS）对转化产物进行分析。沉积物中的生物转化在化学物质与沉积物初次接触后很快开始，并持续了几个月，速率顺序如下：20摄氏度下的细粒沉积物＞10摄氏度下的细粒沉积物＞20摄氏度下的沙质沉积物＞10摄氏度下的沙质沉积物。所有条件下的生物转化路径似乎相似。2,6 - DNT的主要生物转化产物是2 - 氨基 - 6 - 硝基甲苯（2 - A - 6 - NT）。还鉴定出了2 - 硝基甲苯（2 - NT）和其他次要成分，包括N,N - 二甲基 - 3 - 硝基苯胺、苯腈、甲基氨基 - 2 - 亚硝基苯酚和二氨基苯酚。经过更长时间的孵育，这些化学物质被高分子量聚合物取代。通过GC/MS鉴定出了苦味酸的几种分解产物，包括2,4 - 二硝基苯酚、氨基二硝基苯酚、3,4 - 二氨基苯酚、氨基硝基苯酚和硝基二氨基苯酚。在模拟太阳辐射（SSR）条件下，评估了海水中2,6 - DNT和苦味酸的光转化。在长达47天的时间里，未观察到海水中苦味酸有明显的光解现象，但2,6 - DNT在初次暴露于SSR后很快开始光转化，24小时内89%的2,6 - DNT发生了光转化，72小时后无残留。生成了高分子量化学物质，其质谱范围为分子量200 - 500，而DNT的分子量为182，储备溶液的颜色从清澈变为橙色。质谱的复杂性以及碎片之间的质量差异表明生成了多种聚合物，并且在LC/MS分析过程中共洗脱。
