Portable platform for rapid and indirect photometric determination of water in ethanol fuel samplesElectronic supplementary information (ESI) available: (i) Electronic circuit of the photometry system (ii) analytical curves related to the investigated concentrations of Ce(iv) complex and HNO3, (iii) photos showing the colors of the solutions during the complexation reactions until 180 min and (vi) results of storage stability test in three different temperatures. See DOI: 10.1039/c4ay02255f

• Main Authors: Giordano, Gabriela Furlan, Melo Ferreira, Danielle Cristhina, Ribeiro de Carvalho, Thiago, Silveira Vieira, Luis Carlos, Helena de Oliveira Piazzetta, Maria, Lima, Renato Sousa, Gobbi, Angelo Luiz
• Format: Article
• Language: English
• ISSN: 1759-9660; 1759-9679
• DOI: 10.1039/c4ay02255f

We have developed a simple, fast, portable, inexpensive, and indirect method for the determination of water in ethanol fuels. The addition of an excess amount of water is the most simple and common method of adulterating these fuels. Such procedure can adversely affect the performance of the vehicle. Our system uses a laboratory-made photometry device to monitor the formation of complexes between ethanol and cerium( iv ). These reactions produce deep orange-red solutions. The limit of detection and the analytical sensitivity were estimated to be 0.22% v/v (water in ethanol) and 0.11 (% v/v) −1 , respectively. The developed platform was satisfactorily robust with respect to the changes in temperature and stability of the reagents during storage. The measurements were accurate at the 95% confidence level compared with data obtained by Karl Fischer titration. Custom-designed device for the on-site photometric determination of water in ethanol fuels. The method is both user-friendly and fast.