A copper interdigitated electrode and chemometrical tools used for the discrimination of the adulteration of ethanol fuel with water

Author(s)

Bueno, Ligia ^[1] ; Paixao, Thiago R. L. C. ^{[1, 2]}

Affiliation

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Santo Andre, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim, BR-05508900 Sao Paulo - Brazil

• Document type: Journal article
• Source: Talanta; v. 87, p. 210-215, DEC 15 2011.
• Web of Science Citations: 18

Abstract

A new approach for the discrimination of the adulteration process of ethanol fuel with water is reported using a copper interdigitated electrode and chemometrical tools. The sensor was constructed using copper sheets with non-chemical modification of the electrode surface. The discrimination process was performed using capacitance values recorded at different frequencies (1000 Hz to 0.1 MHz) as the input data for non-supervised pattern recognition methods (PCA: principal component analysis and HCA: hierarchical cluster analysis). The relative standard deviation for the capacitance signals obtained from ten independent interdigitated sensors was below 5.0%. The ability of the device to differentiate nonadulterated ethanol samples from those adulterated with water was demonstrated. In all analysed cases, there was good separation between the different samples in the score plots and the dendrograms obtained from PCA and hierarchical cluster analyses, respectively. Furthermore, the water content was quantified using a PCA approach. The results were consistent with those obtained using the Karl-Fischer method at a 95% confidence level, as measured using Student's t-test. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 09/07859-1 - Development of voltammetric electronic tongues towards the characterization and identification of adulteration and falsification processes of biofuels
• Grantee: Thiago Regis Longo Cesar da Paixão
• Support Opportunities: Regular Research Grants