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- doped 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, eluent type/volume/concentration, interfering ion effects and sample volume. The sample pH, eluent concentration/volume and sample volume were 3, 2 mol L−1 HCl/1 mL and 60 mL, respectively. The adsorption/desorption kinetics of the developed d-SPµE were very fast, and the extraction time was only 30 s (30 s 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 2.0 µg L−1, respectively. The RSD% (n=5) of the extraction method was found to be ≤ 3.0%. The high tolerable interfering ion 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 1573a Tomato Leaves 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.