Investigation of 1-Dodecylimidazolium Modified Filter Papers as a Thin-Film Microextraction Phase for the Preconcentration of Bisphenol A from Plant Oil Samples

: Based on the tunability of ionic liquids (ILs) according to the specific requirement of an application, 1-dodecylimidazolium chloride with amphiphilic structures was chemically fabricated on the surface of filter papers (DIL-FPs) for the first time. After synthesis, DIL-FPs was characterized by scanning electronic microscopy, energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy. DIL-FPs was used as a novel thin-film microextraction (TFME) phase for the preconcentration of amphiphilic bisphenol A from plant oil samples. The related extraction variables were studied in a spiked sunflower seed oil. Under the optimal conditions, the linear range was 5.0 - 1000 μg L-1 with a correlation coefficient of 0.9976. The limit of detection (S/N = 3) and the enrichment factor of the proposed method were 2.7 μg L-1 and 118, respectively. The intra-day precision and inter-day precision for six repeated determinations were 2.3 and 4.9%, respectively. These plant oil samples used in this work were free of bisphenol A contaminations. The recovery study carried out in different plant oil samples and mean recoveries ranged from 77.16 to 97.10%. The developed DIL-FPs extraction film phase followed by HPLC-UV provides a potential pretreatment strategy for the analysis of weak organic acid compounds in plant oil samples.