Microextraction of hydrochlorothiazide across protected liquid membrane containing Aliquat-336

Liquid–liquid microextraction with hollow fibers in high-performance liquid chromatography (HPLC) has been applied as a rapid and sensitive quantitative method for the detection of hydrochlorothiazide inhuman urine samples. The preconcentration procedure was induced by the pH difference inside andoutside the hollow fiber. The target compounds were extracted from 24-ml aqueous sample (donor solution, pH 12.0) through a microfilm of organic solvent (1-octanol), immobilized in the pores of a hollow fiber, and finally into 24 μl of 1-octanol. After a prescribed period of time, the acceptor solution inside the fiber was withdrawn into the microsyringe and directly injected into the HPLC system for analysis. Factors relevant to the extraction procedure were studied. Up to 126-fold enrichment of analytes could be obtained under the optimized conditions. The procedure also served as a sample clean-up step. The influence of Aliquat-336 on the extraction efficiency was also investigated, and more than 85% relative recovery of the analyte in urine sample was achieved.

Keywords:

Hollow fiber liquid phase microextraction , HPLC , Hydrochlorothiazide , Aliquat-336