Department of Environmental Sciences, College of the Coast and Environment, Louisiana State University , 1285 Energy, Coast, and Environment Building, Baton Rouge, Louisiana 70803, United States.
Department of Oceanography and Coastal Sciences, College of the Coast and Environment, Louisiana State University , 1002-Y Energy, Coast, and Environment Building, Baton Rouge, Louisiana 70803, United States.
Environ Sci Technol. 2016 Sep 6;50(17):9061-9. doi: 10.1021/acs.est.6b01156. Epub 2016 Aug 10.
Gulf of Mexico saltmarsh sediments were heavily impacted by Macondo well oil (MWO) released from the 2010 Deepwater Horizon (DWH) oil spill. Detailed molecular-level characterization of sediment extracts collected over 48 months post-spill highlights the chemical complexity of highly polar, oxygen-containing compounds that remain environmentally persistent. Electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), combined with chromatographic prefractionation, correlates bulk chemical properties to elemental compositions of oil-transformation products as a function of time. Carboxylic acid incorporation into parent MWO hydrocarbons detected in sediment extracts (corrected for mass loss relative to C30 hopane) proceeds with an increase of ∼3-fold in O2 species after 9 months to a maximum of a ∼5.5-fold increase after 36 months, compared to the parent MWO. More importantly, higher-order oxygenated compounds (O4-O6) not detected in the parent MWO increase in relative abundance with time as lower-order oxygenated species are transformed into highly polar, oxygen-containing compounds (Ox, where x > 3). Here, we present the first molecular-level characterization of temporal compositional changes that occur in Deepwater Horizon derived oil contamination deposited in a saltmarsh ecosystem from 9 to 48 months post-spill and identify highly oxidized Macondo well oil compounds that are not detectable by routine gas-chromatography-based techniques.
墨西哥湾盐沼沉积物受到 2010 年深海地平线（DWH）石油泄漏事件中马孔多油井（MWO）的严重影响。对泄漏后 48 个月内采集的沉积物提取物进行的详细分子水平表征突出了高度极性含氧化合物的化学复杂性，这些化合物在环境中仍然持久存在。电喷雾电离（ESI）傅里叶变换离子回旋共振质谱（FT-ICR-MS）与色谱预分级相结合，将整体化学性质与油转化产物的元素组成相关联，作为时间的函数。在沉积物提取物中检测到母体 MWO 碳氢化合物中羧酸的掺入（相对于 C30 藿烷的质量损失进行校正），在 9 个月后 O2 物质增加了约 3 倍，在 36 个月后达到最大增加了约 5.5 倍，与母体 MWO 相比。更重要的是，母体 MWO 中未检测到的更高阶含氧化合物（O4-O6）随着时间的推移相对丰度增加，因为较低阶含氧物质转化为高度极性含氧化合物（Ox，其中 x > 3）。在这里，我们首次对在深海地平线衍生的油污在盐沼生态系统中沉积后 9 至 48 个月内发生的时间组成变化进行了分子水平的表征，并确定了常规气相色谱技术无法检测到的高度氧化的马孔多油井化合物。
