A Reflectance Flow-through Thionine Sol-gel Sensor for the Determination of Se(IV)

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Carvalhido, JAE (Author) Other; Agostinho Almeida (Author) FFUP; Araujo, AN (Author) FFUP; Montenegro, MCBSM (Author) FFUP

Journal

Title: Analytical Sciences

Vol. 26 No. 6

Pages: 665-669

ISSN: 0910-6340

Publisher: Japan Society for Analytical Chemistry

Indexing

ISI Web of Knowledge - 1 Citation

ISI Web of Science

Scopus - 1 Citation

Pubmed / Medline

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-003-5TJ

DOI: 10.2116/analsci.26.665

Resumo (PT): In this work, a reversible sensor to assess the total Se(IV) content in samples is described. Pre-activated glass slides were spin-coated with 100 μL of a 20-h aged sol-gel mixture of 1 mL of tetramethoxysilane, 305 μL of 50 mmol L−1 HCl and 2.0 mg of thonine. The flow-cell consisted of one of those slides as a window, and was filled with beads of a polystyrene anionic exchange resin to retain Se(IV) in the form of selenite ions. A reflectance transduction scheme at a wavelength of 596 nm was adopted. The cell was coupled to a multicommutation flow system where a programmed volume of a sample solution and 373 μL of 0.4 mmol L−1 iodide in a 1.6 mol L−1 HCl solution were sequentially inserted into the cell. The iodine produced from the reaction of retained Se(IV) with iodide bleached the blue color of thionine. Considering a sample volume of 2.30 mL, with which the preconcentration step was minimized, a linear dynamic working range between 1.5 to 20 μg mL−1 and a detection limit of 0.29 μg mL−1 were obtained. The sensor enabled us to perform approximately 200 assays, and provided results similar to those of electrothermal atomic absorption spectrometry. <br> <br> <a target="_blank" href="http://www.jstage.jst.go.jp/article/analsci/26/6/26_665/_article"> Texto integral </a> <br> <br>

Abstract (EN): In this work, a reversible sensor to assess the total Se(W) content in samples is described. Pre-activated glass slides were spin-coated with 100 mu L of a 20-h aged sol-gel mixture of 1 mL of tetramethoxysilane, 305 mu L of 50 mmol L(-1) HCl and 2.0 mg of thonine. The flow-cell consisted of one of those slides as a window, and was filled with beads of a polystyrene anionic exchange resin to retain Se(IV) in the form of selenite ions. A reflectance transduction scheme at a wavelength of 596 nm was adopted. The cell was coupled to a multicommutation flow system where a programmed volume of a sample solution and 373 mu L of 0.4 mmol L(-1) iodide in a 1.6 mol L(-1) HCl solution were sequentially inserted into the cell. The iodine produced from the reaction of retained Se(IV) with iodide bleached the blue color of thionine. Considering a sample volume of 2.30 mL, with which the preconcentration step was minimized, a linear dynamic working range between 1.5 to 20 mu L mL(-1) and a detection limit of 0.29 mu L mL(-1) were obtained. The sensor enabled us to perform approximately 200 assays, and provided results similar to those of electrothermal atomic absorption spectrometry.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5