Magnetic nanocomposite of chitosan-Schiff base grafted graphene oxide for lead analysis in whole blood

A new Schiff base grafted graphene oxide-magnetic chitosan was utilized as a novel sorbent for extraction and quantification of lead ion in blood samples via dispersive magnetic solid phase extraction. The prepared nanocomposite sorbent was characterized by SEM, TEM, FT-IR, XRD, VSM and EDX and the quantification analysis was performed by microsampling flame atomic absorption spectrometry. The important parameters on the extraction efficiency were thoroughly optimized by means of experimental design. Under the optimized conditions, an aliquot of 50 mL of sample (pH 6.3) was extracted utilizing 60 mg of magnetic nanoparticles during 30 min. The sorbent was afterward desorbed using 1.0 mL of 0.8 mol L-1 HNO3 under fierce vortex for 6 min. A pre-concentration factor of 20 and an absolute recovery of 40% were provided by the proposed method. The limits of detection (3S/N) and quantification (10 S/N) were 0.06 ng mL(-1) and 2.0 ng mL(-1), respectively. An excellent linearity was achieved within the range of (10-800) ng mL(-1) and the regression coefficient was 0.9903. The infra- and inter-day RSDs% were found to be 1.8% and 7.0%, respectively. Furthermore, the method was applied for analysis of blood samples and good accuracies within the range of 97%-108% were obtained.