Application of a titania thin film for the discrimination between diesel fuel and heating oil

The aim of the paper is to show that chemiresistors based on the TiO2 thin film can be used for the discrimination between diesel fuel, heating oil and their blends if coupled with a suitable measuring procedure and pattern recognition technique. The titania layer was prepared with sol-gel technique. A film response of the TiO2 layer was measured at the temperatures of 275, 360 and 440 degrees C. The response of chemiresistors to fuel vapours depended on temperature of the sensitive material. The most apparent differences between oils appeared at the temperature of 360 degrees C. Principal Component Analysis qualitatively indicated the possibility of discrimination between oils at the sensing layer temperature of 360 degrees C. The actual discrimination was obtained with Linear Discriminant Analysis. It used first two principal components extracted from the measurement data collected at 360 degrees C as input variables. Our results indicate the possibility to develop a method of discrimination between diesel fuel and heating oil, based on measurements of electrical signals generated by the film in the presence of detected vapours. (C) 2007 Elsevier B.V. All rights reserved.