title: Development and application of an integrated system for monitoring ethanol content of fuels.
abstract: An automated flow injection analysis (FIA) system for quantifying ethanol was developed using alcohol oxidase, horseradish peroxidase, 4-amino-phenazone, and phenol. A colorimetric detection method was developed using two different methods of analysis, with free and immobilized enzymes. The system with free enzymes permitted analysis of standard ethanol solution in a range of 0.05-1.0 g of ethanol/L without external dilution, a sampling frequency of 15 analyses/h, and relative SD of 3.5%. A new system was designed consisting of a microreactor with a 0.91-mL internal volume filled with alcohol oxidase immobilized on glass beads and an addition of free peroxidase, adapted in an FIA line, for continued reuse. This integrated biosensor-FIA system is being used for quality control of biofuels, gasohol, and hydrated ethanol. The FIA system integrated with the microreactor showed a calibration curve in the range of 0.05-1.5 g of ethanol/L, and good results were obtained compared with the ethanol content measured by high-performance liquid chromatography and gas chromatography standard methods.
authors.affiliation: Departamento de Engenharia Química, Escola de Química, CT/UFRJ, Ilha do Fundão, Cidade Universitária, CEP 21.949.900, Rio de Janeiro, RJ, Brasil.
authors.forename: Eliana M
authors.initials: EM
authors.lastname: Alhadeff
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Salgado
authors.forename: Nei
authors.initials: N
authors.lastname: Pereira
authors.forename: Belkis
authors.initials: B
authors.lastname: Valdman
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry; D000675:Ampyrone / Q000737:chemistry; D015374:Biosensing Techniques; D001709:Biotechnology / Q000379:methods*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D004798:Enzymes / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D019800:Phenol / Q000737:chemistry; D013997:Time Factors
chemical_list: D004798:Enzymes; D000675:Ampyrone; D019800:Phenol; D000431:Ethanol; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D006735:Horseradish Peroxidase