Isotopic constraints on the fate of petroleum residues sequestered in salt marsh sediments.
Isotopic constraints on the fate of petroleum residues sequestered in salt marsh sediments.
复制标题
同位素对盐沼沉积物中石油残留物命运的限制。
DOI：
10.1021/es048675f
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发表时间：
2005
影响因子：
11.4
通讯作者：
T. Eglinton
中科院分区：
文献类型：
--
作者：
H. K. White;C. Reddy;T. Eglinton
为了提供石油在海洋环境中的命运的新视角，我们利用放射性碳（14 C）的天然丰度的变化来检测和量化已经持续在Wild Harbor沉积物中的石油残留物，West Falmouth，MA，超过30年。14 C的5730年半衰期使这种同位素成为检测环境基质中天然有机物（现代14 C含量）不同组分中化石燃料衍生污染物（不含14 C）的理想同位素。污染和未污染的沉积物样品依次处理，首先通过溶剂萃取，然后皂化，然后酸水解。对沉积物残留物和选定提取物进行放射性碳分析，以探测不同沉积有机物池中是否存在化石燃料污染物和/或其代谢物。我们的研究结果表明，大部分的化石碳是溶剂提取，并没有被纳入沉积物中的不溶性有机质。未提取的石油污染的沉积物含有显着低于14 C提取的沉积物，同位素质量平衡计算表明，高达约9%的总有机碳（TOC）的石油污染的沉积层是来自溶剂可提取的石油。这些估计数与将石油总量（通过气相色谱法和火焰离子化检测器（GC-FID）测定）与总有机碳含量（通过元素分析测定）进行比较后计算出的数值相似。这些结果为将这种同位素方法应用于更复杂的环境系统铺平了道路，在这些系统中污染物的命运不太确定。
To provide a new perspective on the fate of petroleum in the marine environment, we utilized variations in the natural abundance of radiocarbon (14C) to detect and quantify petroleum residues that have persisted in Wild Harbor sediments, West Falmouth, MA, for more than 30 years. The 5730-yr half-life of 14C makes this isotope ideal for the detection of fossil-fuel-derived contaminants (14C free) within different fractions of natural organic matter (modern 14C content) in environmental matrixes. Samples of both contaminated and uncontaminated sediments were sequentially treated, first by solvent extraction, followed by saponification, and then acid hydrolysis. Radiocarbon analysis of the sediment residues and select extracts was performed to probe for the presence of fossil fuel contaminants and/or their metabolites in different pools of sedimentary organic matter. Our results indicate that the majority of fossil carbon is solvent-extractable and has not been incorporated in the insoluble organic matter in sediment. Unextracted sediments contaminated with petroleum contain significantly less 14C than extracted sediments, and isotope mass balance calculations suggest that up to approximately 9% of the total organic carbon (TOC) in the petroleum contaminated sediment horizons is derived from solvent-extractable petroleum. These estimates are similar to values calculated when the total quantities of oil (measured by gas chromatography with flame ionization detector (GC-FID)) are compared to TOC content (determined by elemental analysis). These results pave the way for applications of this isotopic approach to more complex environmental systems where the fate of contaminants is less certain.