Kukkonen J V K, Landrum P F, Mitra S, Gossiaux D C, Gunnarsson J, Weston D
Department of Biology, University of Joensuu, Joensuu, Finland.
Environ Sci Technol. 2003 Oct 15;37(20):4656-63. doi: 10.1021/es0342594.
Measures of desorption are currently considered important as potential surrogates for bioaccumulation as measures of the bioavailability of sediment-sorbed contaminants. This study determined desorption rates of four laboratory spiked compounds, benzo[a]pyrene (BaP), 2,4,5,2',4',5'-hexachlorobiphenyl (HCBP), 3,4,3',4'-tetrachlorobiphenyl (TCBP), and pyrene (PY), to evaluate the effect of sediment characteristics. The compounds were sorbed onto seven sediments with a broad range of characteristics. Desorption was measured by Tenax-TA extraction from aqueous sediment suspensions. Desorption rates were modeled using an empirical three compartment model describing operationally defined rapid, slow, and very slow compartments. The sediments were characterized for plant pigments, organic carbon (OC), total nitrogen (TN), lipids, NaOH extractable residue, lignin, amino acids, soot carbon, and particle size fractions. Desorption from the rapid compartment for each of the planar compounds BaP, PY, and TCBP was significantly correlated to sediment characteristics that could be considered to represent younger (i.e., less diagenetically altered) organic matter, e.g., plant pigment, lipid, and lignin contents. However, for these compounds there were no significant correlations between desorption and OC, TN, soot carbon, or amino acid contents. HCBP desorption was different from the three planar molecules. For HCBP, the flux from the rapid compartment was negatively correlated (0.1 > p > 0.05) with the OC content of the sediment. Overall, HCBP desorption was dominated by the amount of OC and the particle size distribution of the sediments, while desorption of the planar compounds was dominated more by the compositional aspects of the organic matter.
作为沉积物吸附污染物生物有效性的衡量指标，解吸测量目前被视为生物累积的潜在替代指标。本研究测定了四种实验室加标化合物（苯并[a]芘（BaP）、2,4,5,2',4',5'-六氯联苯（HCBP）、3,4,3',4'-四氯联苯（TCBP）和芘（PY））的解吸速率，以评估沉积物特性的影响。这些化合物被吸附到七种具有广泛特性的沉积物上。通过从水相沉积物悬浮液中用Tenax-TA萃取来测量解吸。解吸速率使用一个经验性的三室模型进行模拟，该模型描述了操作定义的快速、缓慢和非常缓慢的隔室。对沉积物的植物色素、有机碳（OC）、总氮（TN）、脂质、可被氢氧化钠提取的残留物、木质素、氨基酸、烟灰碳和粒度级分进行了表征。平面化合物BaP、PY和TCBP各自从快速隔室的解吸与可被视为代表较年轻（即成岩作用改变较小）的有机物质的沉积物特性显著相关，例如植物色素、脂质和木质素含量。然而，对于这些化合物，解吸与OC、TN、烟灰碳或氨基酸含量之间没有显著相关性。HCBP的解吸与这三种平面分子不同。对于HCBP，来自快速隔室的通量与沉积物的OC含量呈负相关（0.1 > p > 0.05）。总体而言，HCBP的解吸主要受沉积物的OC含量和粒度分布的影响，而平面化合物的解吸更多地受有机物质组成方面的影响。
