Dopamine-modified magnetic graphene oxide as a recoverable sorbent for the preconcentration of metal ions by an effervescence-assisted dispersive micro solid-phase extraction procedure

Abstract

Nanomagnetic graphene oxide modified with dopamine (GO–Fe₃O₄–DA) was synthesized via a very simple procedure. Using GO–Fe₃O₄–DA as the new adsorbent, the effervescence-assisted dispersive micro solid-phase extraction procedure was exploited for the preconcentrative extraction of Cu(II), Pb(II) and Ni(II) ions. Structural characteristics of the adsorbent were studied via FT-IR, FE-SEM, EDX and XRD analyses. The rapid dispersion and high adsorption capability of GO–Fe₃O₄–DA, along with the rapid separation of the adsorbent from the aqueous phase by a magnet, led to a decrease in the extraction time of the target metal ions. In effect, high extraction percentages were attained in a very short time period. In this work, the relative standard deviations (RSD; n = 3) calculated for the proposed method were 1.09, 1.25 and 1.03% for the Pb(II), Cu(II) and Ni(II) ions, respectively, the calibration curve was dynamically linear in the range of 0.25 to 50 μg L⁻¹, and the limits of detection were obtained as 0.5, 0.1, and 0.7 μg L⁻¹. The procedure was also implemented on real sausage (herbal and meaty) samples and a water sample, vouchsafing the success of the proposed method in tackling real samples with a complicated matrix.