title: Core-shell electrospun polybutylene terephthalate/polypyrrole hollow nanofibers for micro-solid phase extraction.
abstract: In the present work, a new micro-solid phase extraction (μ-SPE) sorbent as an extracting medium based on core-shell nanofibers was synthesized by electrospinning. The core-shell nanofibers of polyvinylpyrrolidone-Polybutylene terephthalate/polypyrrole (PVP-PBT/PPy) were electrospun and subsequently, modified hollow nanofibers were prepared by removing the central PVP moiety. Moreover, conventional PBT/PPy was also prepared for the comparison purposes. The homogeneity and the porous surface structure of the core-shell nanofibers were confirmed by scanning electron microscopy (SEM). The applicability of the fabricated nanofibers-coating was examined by immersed μ-SPE of some selected triazine herbicides from aqueous samples and wheat grains. Subsequently, the extracted analytes were transferred into a gas chromatography (GC) after solvent desorption. Influencing parameters on the morphology of nanofiber such as elctrospinning parameters and the weight ratio of components were optimized. In addition, effects of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength, sample pH, desorption temperature, and desorption time were investigated and optimized. Eventually, the developed method was validated by gas chromatography-mass spectrometry (GC-MS). At the optimum conditions, the relative standard deviation values for real water samples spiked with the selected triazines at 1 ng mL(-1) were 4-8% (n=3) and the limits of detection for the studied compounds were between 50 and 90 ng L(-1). The calibration curves for the selected triazines were in the range of 0.3-500 ng mL(-1) and regression coefficients (R(2)) were between 0.9985 and 0.9996.
authors.affiliation: Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran. Electronic address: bagheri@sharif.edu.
authors.forename: Habib
authors.initials: H
authors.lastname: Bagheri
authors.affiliation: Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
authors.forename: Omid
authors.initials: O
authors.lastname: Rezvani
authors.affiliation: Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
authors.forename: Solmaz
authors.initials: S
authors.lastname: Banihashemi
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D057139:Nanofibers / Q000737:chemistry*; D009994:Osmolar Concentration; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D011758:Pyrroles / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods*; D014227:Triazines / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011091:Polyesters; D011108:Polymers; D011758:Pyrroles; D014227:Triazines; D014874:Water Pollutants, Chemical; C041733:poly(1,4-butylene terephthalate); C067635:polypyrrole
keywords: Core–shell electrospinning; Gas chromatography–mass spectrometry; Hollow nanofibers; Triazines; μ-Solid phase extraction