Polypyrrole/graphene composite‐coated fiber for the solid‐phase microextraction of phenols

A polypyrrole (Ppy)/graphene (G) composite was developed and applied as a novel coating for use in solid‐phase microextraction (SPME) coupled with gas chromatography (GC). The Ppy/G‐coated fiber was prepared by electrochemically polymerizing pyrrole and G on a stainless‐steel wire. The extraction efficiency of Ppy/G‐coated fiber for five phenols was the highest compared with the fibers coated with either Ppy or Ppy/graphene oxide (GO) using the same method preparation. Significantly, compared with various commercial fibers, the extraction efficiency of Ppy/G‐coated fiber is better than or comparable to 85 μm CAR/PDMS fiber (best extraction efficiency of phenol, o‐cresol, and m‐cresol in commercial fibers) and 85 μm polyacrylate (PA) fiber (best extraction efficiency of 2,4‐dichlorophenol and p‐bromophenol in commercial fibers). The effects of extraction and desorption parameters such as extraction time, stirring rate, and desorption temperature and time on the extraction/desorption efficiency were investigated and optimized. The calibration curves were linear from 10 to 1000 μg/L for o‐cresol, m‐cresol, p‐bromophenol, and 2,4‐dichlorophenol, and from 50 to 1000 μg/L for phenol. The detection limits were within the range 0.34–3.4 μg/L. The single fiber and fiber‐to‐fiber reproducibilities were