Determination of partition coefficients for nitrophenols using three phase hollow fiber liquid phase microextraction

A hollow fiber supported liquid phase microextraction method for determination of nitrophenols has been developed.In this work, selected phenolic compounds (2-nitrophenols, 3-nitrophenols, 4-nitrophenols, 2,4-dinitrophenols and 2,6-dinitrophenols) were extracted from the aqueous donor solution by three phase liquid phase microextraction (LPME) based on the migration of the analytes through a thin layer of organic solvent immobilized within the pores of the wall of porous hollow fiber into a small (a few μL) volume of acceptor solution inside the lumen of the hollow fiber. After extraction, the acceptor solution was injected to capillary zone electrophoresis (CZE) system for analysis. Different parameters affecting the extraction process such as extraction time, length of hollow fiber and organic solvent have been studied. Partition coefficients of the analytes were found to be directly related to the enrichment factor. High partition coefficients and enrichment factors can be obtained by proper selection of the organic solvent and by pH condition in the aqueous solutions