NiCo2O4@ZnCo2O4 nanomaterial for selective and fast dispersive solid phase micro-extraction of manganese and lead in water, tea and cinnamon samples followed by FAAS determination

Abstract

NiCo2O4@ZnCo2O4 nanomaterial was synthesized and XRD, FTIR, FESEM, zeta potential measurements, and BET were used for characterization. It was first used as a sorbent for simultaneous dispersive solid phase micro extraction (d-SPµE) of manganese and lead in water, tea and cinnamon. The determination of analytes was made by FAAS. The pH, elution conditions, sample volume, contact times, and effect of competing ions on the d-SPµE of manganese and lead was examined. The optimal pH, and eluent for manganese and lead were found to be 4 and 2 mol/L hydrochloric acid (3 mL), respectively. The adsorption was carried out without vortexing and contact time for elution was only 30 s. The LOD and PFs of the d-SPµE for manganese and lead were 1.7 μg L−1, 16.7 for manganese and 4.0 μg L−1, 33.3 for lead, respectively. The tolerable concentrations of interfering ions for analytes were rather high. The accuracy of d-SPµE was confirmed with analyses of BCR-482 Lichen, TMDA-70.2 Lake water, and NIST RM 8704 Buffalo River Sediment and applying d-SPµE to spiked sea water, wastewater, dam water, tea and cinnamon.