Zn-doped CeO2 nanorod based dispersive solid phase micro-extraction of lead in water, black pepper, lentils and tea samples

Abstract

In this work, pristine CeO2 and Zn-doped CeO2 nanorods were prepared through facile hydrothermal process and characterized. The Zn-dopied CeO2 was first used for dispersive solid phase micro extraction (d-SPµE) of lead in water and food. The conditions affecting d-SPµE of lead were optimized. They were pH, adsorption/elution contact time, and eluent type/volume/concentration, interfering ion effects and sample volume. The sample pH, eluent concentration/volume and sample volume were 3, 2molL-1 HCl/1mL and 60mL, respectively. The adsorption/desorption kinetics of the developed d-SPµE were very fast, and the extraction time was only 30s (30s for adsorption and without vortexing for elution). The preconcentration factor (PF) and limit of detection (LOD) of the d-SPµE for lead were 60 and 2.0µgL-1, respectively. The RSD% (n=5) of the extraction method was found to be ≤ 3.0%. The high tolerable interfering ions concentrations were obtained. The sorbent could be used for 46 times. The method was confirmed with analyses of NW-TMDA 54.6 Lake water, SPS-WW1 Batch 114 wastewater and NIST Tomato Leaves 1573a certificate reference materials. The trace lead concentrations in wastewater, dam water, river water, sea water, tea, lentils, and black pepper were determined by d-SPµE-FAAS.