An automatic spectrofluorimetric method for the simultaneous determination of glycerol and ethanol is presented. The method is based on the use of a flow injection (FI) manifold and dehydrogenase enzyme immobilized on controlled-pore glass. The proposed method allows for the simultaneous determination of glycerol (linear range between 1 and 10 pg ml-1, r = 0.9989 and s, el%) and ethanol (linear range between 10 and 100 pg m1-1, r = 0.9998 and s, <0.9%). It was applied to the determination of

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... h analytes in different wines with recoveries between 97 and 105%. The sampling frequency was 60 samples h-1. The results obtained on eight wines were compared with those provided by conventional methods and the agreement between them corroborated the usefulness of the proposed method. Keywords: Glycerol and ethanol determination; immobilized enzyme; flow injection; spectrofluorimetry; wine oxidation of glycerol and ethanol by oxidized (J-nicotinamide adenine dinucleotide (P-NAD+)), catalysed by their corresponding dehydrogenases according to the following reactions: (2) where GlDH and ADH are glycerol dehydrogenase and alcohol dehydrogenase, respectively. The reduced form of the coenzyme, nicotinamide adenine dinucleotide (NADH), formed was monitored spectrofluorimetrically (hex = 340 nm and he, = 460 nm).