固相微萃取技术在估算多环芳烃的辛醇-水分配系数中的应用

Estimation of the Octanol\|Water Partition Coefficients of PAHs by Solid\|Phase Microextraction

采用固相微萃取气相色谱／质谱联用技术分析了水中 １１ 种多环芳烃，并获得其平衡时的分配系数。当固相微萃取纤维上涂渍的固定液被视为一种有机溶剂时，根据萃取系统间线性的自由能关系，建立了聚二甲基硅氧烷水分配系数 （ Ｋｓｗ ） 与正辛醇 水分配系数（ Ｋｏｗ ） 间的关系式，并将其应用于估算其它多环芳烃的未知的醇水分配系数。所建立的方法简单、快速，与 Ｌｅｏ 碎片法相比，可以更精确地估算取代基位置不同的同分异构体的 Ｋｏｗ 。

Eleven PAHs were analyzed by solid\|phase microextraction\|gas chromatography/ion trap detector and their partition coefficients were obtained at equilibrium. When the polymer coating of the fiber may be viewed as one kind of organic solvent, the linear free energy relationship between the polydimethylsiloxane\|water partition coefficient(K sw ) and octanol\|water partition coefficient(K ow ) was established by solid\|phase microextraction, which was log K sw =0.931 8 log K ow 0.205 6 with good correlation coefficient 0.950 4. The linear equation may be used to estimate the octanol\|water partition coefficient of other PAHs and similar H acceptors compounds. Being compared with Leo's method which was based on the additive constitutive nature of the partition coefficient, the solid phase microextraction method may distinguish efficiently K ow of the isomer.