Morphological and Chemical Analysis of the Molecularly-Imprinted Polymer-Based D-Arabinose Sensor on a Modified Electrode with Functionalized Carbon Nanotubes

he sensors modified carbon nanotubes and molecularly imprinted polymers are an excellent choice for the determination of D-arabinose, because they have high selectivity and sensitivity for analysis. This allows the control and optimization of the second generation ethanol production process, given the clear understanding of the chemical changes that occur through the hydrolysis of lignocellulosic biomass. For this reason, the present work presents a chemical study of the functional groups of the chemical species present on the sensor surface by the Fourier transform infrared spectroscopy (FT-IR) technique and a morphological analysis by the scanning electron microscopy (SEM) technique.Fil: Sousa, Miguel S. P.. Universidade de Sao Paulo; BrasilFil: Ferretti, Cristián Alejandro. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Paim, Leonardo L.. Universidade de Sao Paulo; Brasi

Electrooxidation of sulfide by cobalt pentacyanonitrosylferrate film on glassy carbon electrode by cyclic voltammetry

A glassy carbon (GC) electrode was modified with cobalt pentacyanonitrosylferrate (CoPCNF) film. Cyclic voltammetry (CV) of the CoPCNF onto the GC (CoPCNF/GC) shows a redox couple (Fe(III)/Fe(II)) with a standard potential (E(0)') of 580 mV. The current ratio I(pa)/I(pc), remains almost 1, and a peak separation (Delta E(p)) of 106 mV is observed in 0.5 M KNO(3) as the supporting electrolyte. Anodic peak currents were found to be linearly proportional to the scan rate between 10 and 200 mVs(-1), indicating an adsorption-controlled process. The redox couple of the CoPCNF film presents an electrocatalytic response to sulfide in aqueous solution. The analytical curve was linear in the concentration range of 7.5 x 10(-5) to 7.7 x 10(-4) M with a detection limit of 4.6 x 10(-5) M for sulfide ions in 0.5 M KNO(3) solution. (C) 2010 Elsevier Ltd. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Simultaneous Determination of Iron and Copper in Ethanol Fuel Using Nafion/Carbon Nanotubes Electrode

This work presents the analytical method development for iron and copper determination in ethanol fuel. This method was developed using stripping voltammetry with a glassy carbon electrode modified with Nafion/Carbon-nanotubes. With linear sweep stripping voltammetry was achieved a limit of detection of 7.1 x 10(-7) mol L-1 for Fe3+ and 5.1 x 10(-8) mol L-1 for Cu2+. The amperometric sensitivities were 2.0 x 10(6) mu A mol(-1) L for Fe3+ and 2.8 x 10(7) mu A mol(-1) L for Cu2+. The recovery study showed that the method has good accuracy and repeatability, with recovery of 108 and 103% for Fe3+ and Cu2+ respectively.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Determination of Mg (II) in biodiesel by adsorptive stripping voltammetry at a mercury film electrode in the presence of sodium thiopentone

A mercury film electrode was used to determine Mg (II) in biodiesel by adsorptive stripping voltammetry in presence of sodium thiopentone. A linear response was obtained for Mg (II) in the concentration range of 6.0 × 10-7 to 7.0 × 10-6 mol L-1 for SWAdSV and 8.0 × 10-7 to 9.0 × 10-6 mol L-1 for DPAdSV with detection limits of the 2.9 × 10-7 mol L-1 and 3.1 × 10-7 mol L-1, respectively. The method was applied successfully to biodiesel samples and presented goods results of accuracy with recoveries close to 100.0 % for SWAdSV and DPAdSV. © 2013 by ESG.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq