Thumbnail
Access Restriction
Open

Author Santana, Joyce F. S. De ♦ Belian, Mônica F. ♦ Lavorante, André F.
Source J-STAGE
Content type Text
Publisher The Japan Society for Analytical Chemistry
Language English
Subject Keyword Multicommutation ♦ flow injections analysis ♦ wine ♦ malic acid ♦ spectrophotometry
Abstract This work describes an automated procedure to determine L-malic acid (MA) in wine samples using a multicommuted flow analysis. The MA quantification was based on an enzymatic reaction between MA and L-malate dehydrogenase (L-MDH) in the presence of nicotinamide adenine dinucleotide $(NAD^{+}),$ producing nicotinamide adenine dinucleotide dehydrogenase (NADH), which was monitored at 340 nm. The L-MDH was immobilized on a surface of modified silica with amino groups in the presence of glutaraldehyde. For studying optimization, the system was maintained with 200 μL (288 U) of the L-MDH in 0.5 g of modified silica. Under the optimum experimental conditions, a linear response ranging from 0.1 to 1.5 g $L^{−1}$ MA (R = 0.997 and n = 7), a detection (3σ criterion) and quantification (10σ criterion) limit estimated at 0.02 and 0.06 g $L^{−1},$ respectively, a standard deviation relative of 1.8% (n = 7) for a sample of 0.5 g $L^{−1}$ MA, a sampling rate of 67 samples per hour were achieved. Analyzing ten wines samples and applying the t-test to the results found and those obtained using reference procedures (HPLC) provided no significant differences at the 95% confidence level.
ISSN 09106340
Learning Resource Type Article
Publisher Date 2014-06-10
e-ISSN 13482246
Journal Analytical Sciences(analsci)
Volume Number 30
Issue Number 6
Page Count 5
Starting Page 657
Ending Page 661


Open content in new tab

   Open content in new tab