Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/242531
Type: Artigo de periódico
Title: Speciation Analysis Of Chromium In Water Samples Through Sequential Combination Of Dispersive Magnetic Solid Phase Extraction Using Mesoporous Amino-functionalized Fe3o4/sio2 Nanoparticles And Cloud Point Extraction
Author: Diniz
Kristiany Moreira; Teixeira Tarley
Cesar Ricardo
Abstract: The present paper describes the sequential combination of dispersive magnetic solid phase extraction (DMSPE) with cloud point extraction (CPE) as a new nonchromatographic approach for preconcentration/redox speciation of chromium with FAAS detection. The method is based on sequential preconcentradon of Cr(VI) at pH 5.0 onto mesoporous amino-functionalized Fe3O4/SiO2 nanoparticles followed by cloud point extraction of Cr(III) as metallic complex with 4-(2-thiazolylazo)resorcinol (TAR). The variables that play an important role on the performance of both preconcentration methods were thoroughly optimized by means of factorial design. Under optimized condition, an aliquot of 45.0 mL of sample was preconcentrated onto 25 mg of magnetic nanoparticles during 1 min following the elution with 0.5 mL of 2.5 mot HCl. The supernatant containing Cr(III) was then subjected to CPE procedure, which was accomplished by using thermostatic bath at 90 degrees C during 45 min, 5.8 x 10(-4) mol L-1 TAR and 0.3% (v/v) Triton X-114. The method provided preconcentration factors of 16 and 12 times yielding limits of detection (LOD) and quantification (LOQ) of 1.1 and 3.6 mu g L-1 for Cr(VI) and 3.2 and 10.5 mu g L-1 for Cr(III), respectively. A high tolerance toward potentially interfering ions (cations and anions) and humic acid was observed for the method. Precision (n = 10) of the procedure determined as relative standard deviation (RSD) were, 5.8 and 3.7% for Cr(III) using solutions at 15.0 and 165.0 mu g L-1 and 5.5 and 3.0% for Cr(VI) using solutions at 15.0 and 75.0 mu g L-1 concentrations, respectively. The applicability of method was attested by analysis of water samples yielding good recovery values (91.4-103.5%). The accuracy of method was also checked for biological samples using a certified reference material DORM-3 (Fish Protein Certified Reference Material for Trace Metals). (C) 2015 Elsevier B.V. All rights reserved.
Subject: Atomic-absorption-spectrometry
Dual Mini-columns
Heavy-metal Ions
Spectrophotometric Determination
Online Preconcentration
Poly(methacrylic Acid)
Cr(iii)
System
Cr(vi)
Silica
Country: AMSTERDAM
Editor: ELSEVIER SCIENCE BV
Citation: Speciation Analysis Of Chromium In Water Samples Through Sequential Combination Of Dispersive Magnetic Solid Phase Extraction Using Mesoporous Amino-functionalized Fe3o4/sio2 Nanoparticles And Cloud Point Extraction. Elsevier Science Bv, v. 123, p. 185-195 NOV-2015.
Rights: embargo
Identifier DOI: 10.1016/j.microc.2015.06.011
Address: http://www.sciencedirect.com/science/article/pii/S0026265X15001332
Date Issue: 2015
Appears in Collections:Unicamp - Artigos e Outros Documentos

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