Electrospun polymer composite nanofiber-based in-syringe solid phase extraction in tandem with dispersive liquid-liquid microextraction coupled with HPLC-FD for determination of aflatoxins in soybean

Abstract

A fast method based on in-syringe solid phase extraction combined with dispersive liquid-liquid microextraction was developed for extraction of aflatoxins prior to HPLC-FD. Electrospun polyurethane nanofibers doped with graphene oxide were collected on a thin metal net sheet without using a binder, placed into a filter holder between filter papers on a syringe tip and used as an efficient adsorbent for the first time. The major parameters affecting whole extraction efficiency were investigated and optimized. Under the optimum conditions, the limits of detection and the limits of quantification were in the range of 0.09-0.15 and 0.3-0.5 µg kg^-1, respectively. The linear dynamic range was 0.3-1000 µg kg^-1 with determination coefficients of 0.9946-0.9965. The inter- and intra-day precisions were lower than 4.3 and 7.2%, respectively. The method was successfully applied for the determination of aflatoxins B₁, B₂, G₁, and G₂ in soybeans and satisfactory relative recoveries of 76-101% were achieved.

Keywords: Aflatoxins; Dispersive liquid-liquid microextraction; Electrospinning; Electrospun polyurethane-GO nanofibers; HPLC-FD; In-syringe solid phase extraction.