Application of a novel layered by layered graphenized graphite/ Graphene oxide@polyaniline nanocomposite coating for solid phase microextraction of Organophosphorus pesticides from food and environmental samples

An in situ facile layered by layered graphenized graphite/ Graphene oxide@polyaniline nanocomposite (GG/PANI@GO) coating for solid phase microextraction (SPME) was proven successfully by electrochemical methods for determination of some Organophosphorus pesticides (OPPs) in food and environmental samples. The SPME is a simple, fast, sensitive, solventless, easy automation and cost-effective sample preparation technique which combine sample clean-up, extraction, pre-concentration and sample introduction into one step [1]. An ideal fiber for SPME application should have some general properties including: high adsorptive capacity, good thermal, mechanical and chemical stability, low cost, reproducibility and ease in preparation and finally, the ability to extract various classes of compounds with different polarities [2] .Conducting polymers are multifunctional materials with various interesting properties. The electrochemical synthesis of conductive polymers offers high purity, uniformity of deposits, good control of the film thickness, and rate of deposition and oxidation state of the polymer by controlling the electrochemical conditions [3]. In this study a fiber coated with a layered by layered graphenized graphite/ Graphene oxide@ polyaniline nanocomposite (GG/PANI@GO) using electrochemical methods were applied for extraction of the OPPs, as the model analytes. Organophosphorus pesticides have been increasingly used to control pests and prevent diseases that affect various crops, such as fruits, vegetables and cereals. Many of these compounds are highly toxic and pose Significant negative risks to human health and the environment. Therefore, in order to ensure environmental and health safety, it is necessary to develop effective methods to monitor OPP residues in the environment and food [4]. The new studied fiber have large specific area, high chemical stability, good extraction efficiency and low cost. Six important parameters, affecting the extraction efficiency of OPPs, including: adsorption and desorption times, extraction solvent, pH, stirring rate and salt content of the sample were evaluated. Under experimental optimized conditions, the calibration curves are linear (R2≥0.995) and the limit of detection(S/N=3) were ≤1µg L-1 for different OPPs. The applicability of the proposed method was evaluated by the extraction and determination of OPPs from several food and environmental samples.