New polyamide 6 nanofibrous sorbents produced via alternating current electrospinning for the on-line solid phase extraction of small molecules in chromatography systems

Abstract

Nanofibrous materials provide a large extraction capacity owing to their unique structure. Although most research conducted to date has employed nanofibers produced via the direct current (DC) electrospinning method, the resulting nanofibers have disadvantages that limit their practical use. We focused on the investigation of the electrospinning method using alternating current (AC), firstly used for production of the nanofibrous material as sorbent for extraction. The applicability of the new material was reported as a case study for extraction of bisphenol A (BPA), bisphenol S (BPS), butylparaben (BTP), and fenoxycarb (FXC) in high pressure liquid chromatography system. The nanofibrous samples were produced from polyamide 6 (PA 6) by AC electrospinning. The properties of AC electrospun PA 6 material were compared to the nanofibers produced from the same polymer via conventional DC electrospinning. Our results demonstrated the unique ratio of high porosity, fiber diameter, and specific surface area of AC PA 6 material that led to very good stability in high-pressure flow system and absence of undesired flow and back pressure fluctuations. Good repeatability of cartridge packing with RSD 5.22% for AC material and 16.61 % for DC material, and high extraction efficiency ranging from 95 to 145% was achieved. Efficient on-line extraction procedure enabled the limits of detection ranging from 30 to 60 μg L-1 using both nanofibrous materials and UV detector. The slopes of matrix matched calibration curves demonstrated good selectivity of both extraction materials for BPA, BPS, and BTP. We confirmed the usefulness of our novel approach to nanofiber sorbents for SPE that met the exacting demands in the field of advanced flow extraction methods.