RESUMEN

Nickel-manganese-cobalt tetragonal spinel ternary oxide nanocomposite (NMC-TSO) was synthesized. It was utilized as an efficient sorbent for the dispersive solid phase microextraction (D-SPµE) without vortexing of cadmium. The analysis of the cadmium was carried out by FAAS. The effective analytical parameters including pH (6) contact times (no vortexing), sample volume (70 mL), eluent volume (3 mL of 2 mol L-1 HCl), linear dynamic ranges (1.07-85.7 µg L-1), and re-useability (33) on the D-SPµE efficiency were investigated. The PF, RSD% and LOD of the D-SPµE for cadmium were 23.3, ≤ 2.8% and 0.49 µg L-1, respectively. The tolerable concentrations of Ca2+, Mg2+, K+ and Na+ on Cd(II) were 50,000 mg L-1, 50,000 mg L-1, 25,000 mg L-1 and 7500 mg L-1, respectively. The method was accurated by analysis of food and water certificate reference materials (NW-TMDA-54.6 Lake water, SPS-WW1 121 Batch wastewater, 1573a Tomato Leaves and TORT-3 Lobster Hepatopancreas) and - recovery experiments. The D-SPµE-FAAS method was applied for the cadmium determination in dam water, wastewater, river water, well water, sea water, tea, cacao, nut, bitter chocolate, rice, leek, cinnamon and parsley.

Asunto(s)

Cadmio , Cobalto , Contaminación de Alimentos , Manganeso , Nanocompuestos , Níquel , Óxidos , Microextracción en Fase Sólida , Contaminantes Químicos del Agua , Nanocompuestos/química , Adsorción , Óxidos/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Cadmio/química , Cadmio/análisis , Cadmio/aislamiento & purificación , Níquel/química , Níquel/aislamiento & purificación , Contaminación de Alimentos/análisis , Manganeso/química , Manganeso/análisis , Manganeso/aislamiento & purificación , Cobalto/química , Cobalto/aislamiento & purificación

RESUMEN

A fast and simple dispersive solid-phase microextraction method (d-SPµE) was described for the determination of copper and lead in food, water, and sediments using FAAS. Firstly, nanoflower Al2O3@carbon spheres composite (NF Al2O3@CSs) was synthesized and then characterized. The obtained NF Al2O3@CSs was used for the d-SPµE of copper and lead in aqueous solutions. The influence of important parameters like pH, contact time, eluent conditions, volume of sample, and competing ion effects on the d-SPµE efficiency of copper and lead was investigated. They were pH, 7; eluent, 2 mol L-1 HCl (2 mL); sample volume, 250 mL for copper and 150 mL for lead with recoveries ≥90%. The adsorption and elution of analytes on NF Al2O3@CSs were realized quickly without vortexing. The LODs of the d-SPµE for copper and lead were found to be 0.69 µg L-1 and 2.8 µg L-1, respectively, while its PF was 125 for copper and 75 for lead. The intra-day precision and inter-day repeatability (RSD%, n = 7) were 1.3% and 1.6% for Cu(II) and 2.3% and 3.2% for Pb(II), respectively. Finally, the accuracy of the d-SPµE was investigated by determination of the analytes in four certified reference materials (TMDA-53.3 Lake water, NW-TMDA-54.6 Lake water, NIST 1573a Tomato leaves, and NIST RM 8704 Buffalo River Sediment). The analyte recoveries together with analyses of dam water, river water, wastewater, sea water, sumac, tea, chocolate, and lentils were studied. The results indicate that recoveries ranged from 90 to 103% in water samples and 91 to 110% in food samples.