Supported liquid phase extraction using wetted nanofiber discs as a simple approach for in-vial extraction of chlorophenols and insecticides from river water prior to HPLC-DAD analysis

Abstract

BackgroundA novel supported liquid extraction approach using small polymeric nanofibrous discs was demonstrated and applied to the analysis of real river water. Nanofibrous discs were tested to extract model mixture of 9 common water contaminants 4-nitrophenol, various chlorophenols, bisphenol A, permethrin, and fenoxycarb featuring a wide range of log P values (1.9–6.5). Polyacrylonitrile, polyhydroxybutyrate, and polylactic acid nanofibers were selected as adsorptive materials. One-step desorption was performed directly in HPLC vials, to avoid time-consuming evaporation and reconstitution steps. The discs were allowed to sediment to the bottom of the vial before injection into the chromatographic system. ResultsVarious parameters affecting the extraction efficiency including 1-octanol volume, extraction time, ionic strength, and sample volume were investigated and optimized. Wetting the nanofiber discs with 1-octanol resulted in up to 20-fold increase in enrichment factor when compared to non-wetted polymer counterparts. The highest enrichment factors were observed for analytes with a log P range of 3.3–4.5. Our developed method showed good linearity in the range 20–200 μg/L for all analytes tested. Satisfactory repeatability with RSD <13 % were achieved covering all steps including disc preparation, wetting, extraction/elution, and chromatography analysis, and recoveries ranged from 58.93 to 121.43 %. SignificanceThis work represents novel simple supported liquid extraction approach using impregnated polymer nanofiber discs. Using only 50 μL 1-octanol, we reduced the organic solvent compared to other extraction methods. There was no need for any plastic cartridge to hold the sorbent and direct in-vial desorption reduced the unnecessary, time-consuming steps and simplified the sample preparation protocol.