title: Kinetic enzymatic determination of glycerol in wine and beer using a sequential injection system with spectrophotometric detection.
abstract: A sequential injection system for the automatic determination of glycerol in wine and beer was developed. The method is based on the rate of formation of NADH from the reaction of glycerol and NAD+ catalyzed by the enzyme glycerol dehydrogenase in solution. The determination of glycerol was performed between 0.3 and 3.0 mmol L(-1) (0.028 and 0.276 g L(-1)), and good repeatability was attained (rsd < 3.6%, n = 5) for all samples tested. The determination rate was 54 h(-1), the reagent consumption was only 0.75 micromol of NAD+ and 5.4 ng of enzyme per assay, and the waste production was 2.12 mL per assay. Results obtained for samples were in agreement with those obtained with the batch enzymatic method.
authors.affiliation: REQUIMTE, Serviço de Química-Física, Faculdade de Farmacia, Universidade do Porto, Rua Aníbal Cunha 164, 4099-030 Porto, Portugal.
authors.forename: Hugo M
authors.initials: HM
authors.lastname: Oliveira
authors.forename: Marcela A
authors.initials: MA
authors.lastname: Segundo
authors.forename: José L F C
authors.initials: JL
authors.lastname: Lima
authors.forename: Viviane
authors.initials: V
authors.lastname: Grassi
authors.forename: Elias A G
authors.initials: EA
authors.lastname: Zagatto
mesh_terms: D001515:Beer / Q000032:analysis*; D017022:Flow Injection Analysis; D005990:Glycerol / Q000032:analysis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D013053:Spectrophotometry; D013401:Sugar Alcohol Dehydrogenases / Q000378:metabolism; D014920:Wine / Q000032:analysis*
chemical_list: D012996:Solutions; D009243:NAD; D013401:Sugar Alcohol Dehydrogenases; C020672:glycerol dehydrogenase; D005990:Glycerol