Facile synthesis of covalent organic framework incorporated electrospun nanofiber and application to pipette tip solid phase extraction of sulfonamides in meat samples.

In this work, covalent organic frameworks SNW-1 incorporated polyacrylonitrile (SNW-1@PAN) nanofiber was synthesized and used as pipette tip solid phase extraction (PT-SPE) adsorbent for preconcentration of five sulfonamides (SAs) in meat samples. The SNW-1@PAN nanofiber was fabricated via two steps, including the hydrothermal synthesis of SNW-1 and co-electrospinning of the SNW-1/PAN mixture. The three dimensional networks of electrospun nanofiber provide both low backpressure and rapid mass transfer in PT-SPE application, thus preventing the problems of high backpressure and leakage caused by directly packing SNW-1 into PT-SPE cartridge. The SNW-1@PAN nanofiber packed PT-SPE cartridge was used to extract SAs in meat samples followed by high performance liquid chromatography (HPLC). The effects of different parameters influencing the extraction and desorption efficiency were intensively investigated and optimized. Under the optimum conditions, the linear ranges of SAs were in the range of 5-125 ng mL-1 with correlation coefficients above 0.998, and the limits of detection of the five SAs ranged from 1.7 to 2.7 ng mL-1. The interday and intraday precision (RSD) for five replicate extractions of the five SAs (50 ng mL-1 for each) was in the range of 5.4-9.2%. The applicability of the proposed method was examined by analyzing the SAs in the pork and chicken samples. The recoveries of the five SAs varied in the range of 86-111% with good precision, showing the good capability of the proposed method for the determination of SAs in the complicated real samples.