分散液-液微萃取快速、直接测定有机化合物lgP值

用3-氯丙基三甲氧基硅烷对Fe₃O₄纳米球的表面进行改性, 制得表面疏水的Fe₃O₄/SiCH₂CH₃Cl纳米球. 将Fe₃O₄/SiCH₂CH₃Cl纳米球均匀预分散在正辛醇中, 利用分散液-液微萃取建立了快速、 直接测定有机化合物lgP值的新方法. 待测有机化合物可在3 min内在两相达到分配平衡, 通过磁铁吸引含有Fe₃O₄/SiCH₂CH₃Cl纳米球的正辛醇小液滴, 可实现两相快速完全分离. 在萃取过程中, 由于Fe₃O₄/SiCH₂CH₃Cl纳米球被正辛醇包围, 失去对待测化合物的吸附能力, 因此Fe₃O₄/SiCH₂CH₃Cl纳米球对测定有机化合物分配平衡的影响很小. 通过该方法测定了14种不同有机化合物的lgP值, 结果均与文献报道一致. 与其它直接测定方法相比, 该方法快速、 准确、 简单且样品消耗少.

Rapid Direct Method for Determination of lgP Value by Dispersive Liquid/liquid Microextraction

A novel and rapid direct method was developed for the determination of lgP value by dispersive liquid/liquid microextraction(DLLME). The equilibrium of test compound between the two phases was reached in less than 3 min and the two phases were separated quickly by an ultrastrong magnet. Moreover, interruption of absorption of Fe3O4/SiCH2CH3Cl with the partition equilibrium of test compound was negligible because a thick layer 1-octanol was surrounded around their surfaces. The novel method was evaluated with 14 reference compounds and shown to be suitable for accurate determination of lgP value and the upper limit of lgP range was high. This direct method was very quick, accurate and small amount of sample consuming.