title: Dispersive solid phase microextraction with magnetic graphene oxide as the sorbent for separation and preconcentration of ultra-trace amounts of gold ions.
abstract: A selective, simple and rapid dispersive solid phase microextraction was developed using magnetic graphene oxide (MGO) as an efficient sorbent for the separation and preconcentration of gold ions. The MGO was synthesized by means of the simple one step chemical coprecipitation method, characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Gold ions retained by the sorbent were eluted using 0.5mol L(-)(1) thiourea in 0.1mol L(-1) HCl solution and determined by the flow injection flame atomic absorption spectrometry (FI-FAAS). The factors affecting the separation and preconcentration of gold were investigated and optimized. Under the optimized conditions, the method exhibited a linear dynamic range of 0.02-100.0µg L(-)(1) with a detection limit of 4ng L(-1) and an enrichment factor of 500. The relative standard deviations of 3.2% and 4.7% (n=6) were obtained at 20µg L(-1) level of gold ions for the intra and the inter day analysis, respectively. The method was successfully applied to the determination of gold ions in water and waste water samples as well as a certified reference material (CCU-1b, copper flotation concentrate).
authors.affiliation: Department of Chemistry, Yazd University, Safaieh, 89195 Yazd, Iran.
authors.forename: Elahe
authors.initials: E
authors.lastname: Kazemi
authors.affiliation: Department of Chemistry, Yazd University, Safaieh, 89195 Yazd, Iran. Electronic address: sdadfarnia@yazd.ac.ir.
authors.forename: Shayessteh
authors.initials: S
authors.lastname: Dadfarnia
authors.affiliation: Department of Chemistry, Yazd University, Safaieh, 89195 Yazd, Iran.
authors.forename: Ali Mohammad
authors.initials: AM
authors.lastname: Haji Shabani
keywords: Dispersive micro-solid-phase extraction; Fe(3)O(4) nanoparticles; Flame atomic absorption spectrometry; Gold; Graphene oxide