Fibers coated with a graphene-polyaniline nanocomposite for the headspace solid-phase microextraction of organochlorine pesticides from seawater samples

We have prepared a fiber for solid-phase microextraction of organochlorine pesticides. A graphene-polyaniline composite was electrochemically deposited on a platinum fiber by exploiting the unique properties of polyaniline and graphene. The modified fiber displays thermal stability up to 320 A degrees C and can be used more than 70 times. It possesses high extraction efficiency due to the high specific surface of graphene. The Pt fiber was used for the extraction and subsequent GC determination of the pesticides heptachlor, aldrin, endrin and p,p'-DDT in aqueous samples. The effects of extraction time, extraction temperature, stirring rate, salinity and headspace volume were optimized. Calibration plots are linear (with an R-2 of 0.990) in the 0.2 to 250 mu g L-1 concentration range, and the limits of detection are below 11 ng L-1 (at an S/N of 3). The relative standard deviations for three replicate measurements with a single fiber were < 11.0 %. The recovery of the pesticides from spiked seawater samples ranged from 81 % to 112 %.