Artículos de revistas
Synthesis and Characterization of a Silica/Tungsten(VI) Oxide and Its Performance for the On-Line Solid-Phase Extraction (SPE) of Nickel Ions from Aqueous Media with Determination by Flame Atomic Absorption Spectrometry (FAAS)
Fecha
2020-01-01Registro en:
Analytical Letters.
1532-236X
0003-2719
10.1080/00032719.2020.1793997
2-s2.0-85088522646
Autor
Universidade Estadual de Londrina (UEL)
Federal Institute of Parana (IFPR)
Universidade Federal do Rio de Janeiro (UFRJ)
Universidade Estadual Paulista (Unesp)
Universidade Estadual de Campinas (UNICAMP)
Institución
Resumen
The present paper describes a new analytical method exploiting a SiO2/WO3 mixed oxide as an adsorbent synthesized via sol-gel process for the preconcentration of Ni2+. This material was characterized by energy dispersive X-ray fluorescence spectroscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, analysis of the specific surface area by Brauner, Emmett and Telle multipoint method, the average pore size and pore volume by Barrett-Joyner-Halenda method, scanning electron microscopy, and electron dispersive spectroscopy. The mixed oxide presented high surface area (710.9 m2 g−1), average pore size of 35.1 Å, and average pore volume of 0.128 cm−3 g−1. This material was used as the an adsorbent in an on-line procedure for pre-concentration of solid phase extraction, based on the adsorption of Ni2+ ions at pH 10.5 followed by elution with 1.0 mol L−1 HNO3 and determination by flame atomic absorption spectrometry. Under optimized conditions, a linear range from 10.0 to 170.0 µg L−1, an enrichment factor of 38.8-fold, and limits of detection and quantification of 4.23 µg L−1 and 14.11 µg L−1 were obtained. The precision of method, estimated as percentage of relative standard deviation of ten replicates of 30.0, 90.0 and 150.0 µg L−1 Ni2+ solutions, was lower than 4.10%. The method was employed for analysis of water samples and the accuracy was attested by addiction and recovery tests, with satisfactory recoveries (98.4–109.2%). Thus, the developed material can be successfully applied to water samples for monitoring of Ni2+ at very low levels without matrix influence.