【摘要】 建立了研究鱼鳃表面芘的结合状态的四步连续提取方法．分别用H2O、CaCl2、CH3OH和n-C6H14+CH2Cl2(1:1, v/v)混合液提取经暴露的鱼鳃．操作定义的前3步分别提取松散附着在鳃表的鱼鳃黏液中的芘,紧密附着在鳃表的鱼鳃黏液中的芘以及直接吸着在鱼鳃表皮上的芘,第4步则用来提取鱼鳃组织吸收的芘．其提取的芘分别占总量的 4．0％、12．1％、45．2％和38．7％．经3 h暴露,进入鳃组织的芘仅为总测定量的三分之一强,因此大部分芘并未进入鳃组织．单独进行的五步CH3OH连续提取实验结果证明,CH3OH提取步骤能有效地解吸鳃表吸着的芘,但不会导致鳃组织中芘的释放．动态实验结果表明,黏液结合态芘在暴露1h左右即达到平衡,而鳃表吸着态和鳃组织吸收态芘在暴露3h内含量迅速上升,3 h后显著趋缓．更多还原

【Abstract】 A sequential extraction procedure was developed to investigate the binding status of pyrene on fish gill surface. After exposed to pyrene, fish gills were extracted with H2O, CaCl2, CH3OH and a mixture of n - C6H14+CH2Cl2 (1:1, Accelerated Solvent Extraction) in sequence. The four fractions extracted were the pyrene associated with mucus either loosely or strongly adhered to gill surface, the pyrene sorbed directly on the gill surface and the pyrene accumulated in the gill tissues. The results of a preliminary experiment with five-step CH3OH extraction demonstrated that CH3OH would only strip pyrene bound to the gill surface, rather than those within the gill tissues. After three hours exposure, a large portion of pyrene associated with fish gills were on the gill surface. The percentages of the H2O, CaCl2, CH3OH and n-C6H14+CH2Cl2 extracted fractions were 4.0%, 12.1%, 45.2% and 38.7%, respectively. According to the result of a kinetic- experiment, the partition distribution between the water phase and the gill mucus reached equilibrium around 1 h and the changes in other fractions slowed down remarkably after 3 h.更多还原