Preparation, characterization and applications of graphene oxide and oil-palm activated carbon modified magnetic-polypyrrole sorbents for microextraction of selected organic pollutants
Magnetite (Fe3O4) and polypyrrole (PPy) are widely used in the electrical industry. However, their uses as sorbents in analytical chemistry applications are scarce. Thus, this research investigates the preparation, development and applications of Fe3O4-PPy composites as sorbents for microextraction of different emerging and persistent occurring pollutants optimized with the aid of response surface methodology (RSM) approach. In the first part of study, Fe3O4-PPy sorbent was applied in magnetic solid phase extraction (MSPE) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) for the analysis of three selected non-steroidal anti-inflammatory drugs (NSAIDs), namely naproxen, diclofenac and mefenamic acid. Systematic investigations on the synthesis and Fe3O4-PPy MSPE efficiencies for the NSAIDs were successfully modelled using the Box- Behnken Design (BBD) (R2 = 0.94-0.98, p pH sample solution > extraction time > desorption time. The OPACFe3O4- PPy MSPE method demonstrated good linearity (25-1000 ng L-1) with good correlation (R2 > 0.991) and low LODs and LOQs (LOD = 3S/N, 6.5 ng L-1 for ESO and 7.3 ng L-1 for DIE; LOQ = 10S/N, 25 ng L-1 for ESO and DIE) with high recoveries (98105%) of OCPs from tap water, and palm oil effluent samples. A comparative study showed that the incorporation of Fe3O4 and PPy separately to GO and OPAC, showed different behaviours in accordance to the particle size and surface chemistry. The adsorption capacities of the sorbents, represented by qm is in the order of GO-Fe3O4 -PPy > OPAC-Fe3O4 -PPy > Fe3O4-PPy. Thus this study proved that the adsorption strength of sorbents could be reinforced by the presence of OPAC and GO. Analytical Eco-Scale analysis showed that all the developed methods achieved acceptable green analysis scale (AES value: 77-81). The proposed methods offered good features such as sustainable, simple, and rapid extraction that meet the green chemistry concept
