Silica-Alumina-Niobia (SiO2/Al2O3/Nb2O5) Matrix Obtained by the Sol-gel Processing Method: New Material for Online Extraction of Zinc Ions

• Autor(a) principal: Tarley, César Ricardo Teixeira
• Data de Publicação: 2010
• Outros Autores: Ávila, Thiago Carvalho de, Segatelli, Mariana Gava, Lima, Giovana de Fátima, Peregrino, Gabrielly dos Santos, Scheeren, Carla Weber, Dias, Silvio Luís Pereira, Ribeiro, Emerson Schwingel
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da FURG (RI FURG)
• Texto Completo: http://repositorio.furg.br/handle/1/3826
• topic: Adsorbent preconcentration system; Zinc ions; Silica-alumina-niobia; Sol-gel process

In the present work, a new material, SiO2/Al2O3/Nb2O5 (designated as SiAlNb), was evaluated as an adsorbent in a flow injection spectrophotometric method for online preconcentration and determination of trace amounts of Zn2+ ions. The preconcentration method is based on Zn2+ adsorption onto the surface of SiAlNb in alkaline medium (pH 9.0). The elution step is carried out using HNO3 solution, followed by reaction of the Zn2+ ions with 1-(2-piridylazo)-2-naphtol (pan) in ammoniacal buffer solution (pH 9.3) containing Tween-80. The [Zn(pan)2] complex formed is determined at 560 nm. The method presented a linear range between 7.6 and 180.0 µg L-1 (r = 0.9992) and limits of detection and quantification of 2.3 and 7.6 µg L-1, respectively. According to the Langmuir linear model, the maximum adsorption capacity was found to be 7.0 mg of Zn2+ g-1 of SiAlNb. The proposed method was successfully applied to the Zn2+ determination in water samples (lake, mineral, tap) and certified reference material (TORT-2 Lobster Hepatopancreas).