Development of a new and environment friendly hollow fiber-supported liquid phase microextraction using vesicular aggregate-based supramolecular solvent

Hollow fiber-based liquid phase microextraction (HF-LPME) using conventional solvents is limited by their relative instability and high volatility. The use of supramolecular solvents as a liquid membrane phase could overcome these inconveniences due to their negligible vapour pressure and high viscosity. In the present study, a novel and highly flexible method was developed based on supramolecular solvents constructed of vesicles of decanoic acid, which were used for the first time as a solvent in HF-LPME. This solvent is produced from the coacervation of decanoic acid aqueous vesicles by the action of tetrabutylammonium (Bu4N+). In this work, halogenated anilines as model compounds were extracted from water samples into a supramolecular solvent impregnated in the pores and also filled inside the porous polypropylene hollow fiber membrane. The extracted anilines were separated and determined by high-performance liquid chromatography. The technique requires minimal sample preparation time and toxic organic solvent consumption, and provides a significant advantage over conventional analytical methods. The important parameters influencing the extraction efficiency were studied and optimized utilizing two different optimization methods: one variable at a time and the Box-Behnken design. Under the optimum conditions, the preconcentration factors were in the range of 74 to 203. Linearity of the method was obtained in the range of 1.0-100 mu g L-1 with the correlation coefficients of determination (R-2) ranging from 0.9901 to 0.9986. The limits of detection for the target anilines were 0.5-1.0 mu g L-1. The relative standard deviations varied from 3.9% to 6.0%. The relative recoveries of the three halogenated anilines from water samples at a spiking level of 20.0 mu g L-1 were in the range of 90.4-107.4%.