title: Integrated biosensor systems for ethanol analysis.
abstract: Different integrated systems with a bi-enzymatic biosensor, working with two different methods for ethanol detection--flow injection analysis (FIA) or sequential injection analysis (SIA)--were developed and applied for ethanol extracted from gasohol mixtures, as well as for samples of alcoholic beverages and fermentation medium. A detection range of 0.05-1.5 g ethanol/l, with a correlation coefficient of 0.9909, has been reached when using FIA system, working with only one microreactor packed with immobilized alcohol oxidase and injecting free horseradish peroxidase. When using both enzymes, immobilized separately in two microreactors, the detection ranges obtained varied from 0.001 to 0.066 g ethanol/l, without on-line dilution to 0.010-0.047 g ethanol/l when a 1:7,000 dilution ratio was employed, reaching correlation coefficients of 0.9897 and 0.9992, respectively. For the integrated biosensor SIA system with the stop-flow technique, the linear range was 0.005-0.04 g/l, with a correlation coefficient of 0.9922.
authors.affiliation: Escola de Química, Centro de Tecnologia, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Cidade Universitaria, Rio de Janeiro, Brazil. ema@eq.ufrj.br
authors.forename: Eliana M
authors.initials: EM
authors.lastname: Alhadeff
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Salgado
authors.forename: Oriol
authors.initials: O
authors.lastname: Cós
authors.forename: Nei
authors.initials: N
authors.lastname: Pereira
authors.forename: Francisco
authors.initials: F
authors.lastname: Valero
authors.forename: Belkis
authors.initials: B
authors.lastname: Valdman
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003124:Colorimetry / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D000431:Ethanol / Q000032:analysis* / Q000737:chemistry; D017022:Flow Injection Analysis / Q000295:instrumentation*; D006735:Horseradish Peroxidase; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018511:Systems Integration
chemical_list: D004800:Enzymes, Immobilized; D000431:Ethanol; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D006735:Horseradish Peroxidase