Abstract
In contrast to the global health rules, MG still widely used in aquaculture. Due to the low concentrations of this pollutant and identification with conventional equipment, preconcentration methods are required. Therefore preconcentration of solution contain MG was carried out by magnetic nanofibers based on poly(acrylonitrile-co-acrylic acid). The nanosorbents have good magnetic properties and provide a good surface area, which can be very useful in the d-MSPE process. As shown in the schematic diagram, the change in the color and concentration of the contaminated solutions is exploited.
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•Bead less, uniform and continuous magnetic PAN-co-PAA nanofibers were synthesized.•Prepared magnetic nanofibers were used as an efficient solid phase exactor.•MNFs have a smaller diameter (70nm) than pure NFs (360nm).•MNFs were used for pre-concentration of MG residues in water media via d-MSPE.•The detection limit was 0.03mgL−1 and the recoveries were 95.83–103.3%.
This research describes the development of a new design of nanosorbents, magnetic poly(acrylonitrile-co-acrylic acid) (PAN-co-AA) nanofibers, for the pre-concentration of malachite green (MG) residues in water samples via dispersive magnetic solid phase extraction (d-MSPE) technique. After pre-concentration, the spectrophotometric method was used to determine MG. Magnetic PAN-co-AA nonwoven nanofibers was fabricated by the optimized electrospinning technique after optimization of electrospinning conditions. According to the results, increasing magnetic nanoparticles (MNPs) into polymeric matrix led to significant reduction of fiber diameter from 360 to 70nm. This change was associated with an increase in nanofibers surface area (from 9.66m2g−1 to 12.09m2g−1). Fabricated magnetic nanofibers demonstrated suitable magnetic properties (3.6emug−1), so it can be used for magnetic separation and easy extraction techniques. In the following step, magnetic PAN-co-AA nanofibers (MNFs) were used to determine MG in aquatic samples. The influence of different parameters on extraction was investigated and optimized to improve the extraction efficiency of MG. The calibration curve was linear in the range of 0.3–1.8mgL−1 of MG with R2=0.9911. The detection limit, based on three times the standard deviation of the blank, was 0.03mgL−1. The relative standard deviation (RSD) for 1, 1.5 and 1.8mgL−1 of MG was 4.31%, 6.86% and 7.68% (n=6), respectively. MG was analyzed in different water samples (urban, mineral and river waters) using the proposed method. The recoveries were 95.83–103.3% with an RSD of less than 8%. The results showed that MNFs were suitable for pre-concentration and determination of trace amount of MG in wastewater samples.