超临界流体萃取在研究土壤和沉积物结合态残留中的应用

许多有机污染物在土壤和沉积物中形成持久稳定的结合态残留；结合态残留对土壤和沉积物的解毒过程、污染物长期分配行为、生物可用性和生物毒性都具有重要影响。为了揭示结合态残留的形成机制及其对污染物环境行为和毒理学参数的影响，从土壤或沉积物中提取出不同结合状态的有机污染物就显得非常重要。超临界流体萃取(SFE)可以实现选择性萃取，从而得到有关污染物一基体间相互作用的信息。文章介绍了SFE应用类型、超临界流体种类以及影响SFE萃取率的因素，对SFE模拟有机污染物长期吸附／解吸行为和生物可用性研究进行了论述，并认为SFE势必发展成为土壤或沉积物中结合态残留形成机理研究、土壤修复和生态风险评价的一种强有力的技术。

Application of supercritical fluid extraction in study of bound residues in soil and sediment

It has been shown that many organic pollutants form persistent bound residues in soils and sediments, which play an important role in soil and sediment detoxification processes, long-term partitioning behavior, bioavailability and toxicity of the pollutants in soil and sediment. To disclose the formation mechanisms of the bound residue and its subsequent influences on environmental and toxicological fate of the pollutants, extraction of various organic pollutants from soil and sediment is considered to be important. Supercritical fluid extraction (SFE) technique could provide the dissimilar interaction information between pollutants and matrix by selective extraction. In this paper, application types of SFE, kinds of supercritical fluids and the influencing factors on extraction efficiency have been introduced. Moreover, applications of SFE in simulating long-term sorption/desorption and bioavailability of organic pollutants have been discussed. It is believed that SFE could develop to be a crucial technique in studies, such as formation mechanism of the bound residue in soil and sediment, soil remediation and eco-risk assessment.