Fast and sensitive determination of heavy metal ions as batophenanthroline chelates in food and water samples after dispersive micro-solid phase extraction using graphene oxide as sorbent

A preconcentration procedure is presented for the dispersive micro solid-phase extraction (DMSPE) of trace amounts of Pb(II), Cd(II), Zn(II), Cr(III), Mn(II), and Fe(III) as their batophenanthroline chelate complexes on the graphene oxide (GO) nanosheets prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES) technique. The influence of analytical parameters including pH, type and concentration of eluent, amount of complexing reagent, sorption time and sample volume on the quantitative recoveries of analytes were investigated in order to obtain the optimum conditions. The experiment shows that metal ions can be simultaneously preconcentrated at pH of 8 with high recoveries (in the range of 90-97%) and excellent precision (RSDs within 1.6-3.0%). The detection limits are 0.25, 0.06, 0.16, 0.06, 0.12 and 0.21 ng mL(-1) for Pb (II), Cd(II), Zn(II), Cr(III), Mn(II), and Fe(III), respectively. The method was successfully applied for the determination trace amounts of analytes in food and water samples.