RT Journal Article
SR Electronic
T1 A New Approach to Dialysis in Sequential Injection Systems: Spectrophotometric Determination of L(+)-Lactate in Wines
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP 428
OP 432
DO 10.5344/ajev.1997.48.4.428
VO 48
IS 4
A1 Alberto N. AraÚJO
A1 José L.F.C. Lima
A1 M. Lúcia M.F.S. Saraiva
A1 Elias A.G. Zagatto
YR 1997
UL http://www.ajevonline.org/content/48/4/428.abstract
AB A sequential injection analysis (SIA) system for the spectrophotometric determination of L(+)-lactate using lactate oxidase/peroxidase was developed and applied to wine analysis. It incorporates a dialysis unit between the pump and the selecting valve to provide on-line dilution and interference minimization of the sample matrix. A volume of 100 µL of carrier solution trapped in one channel of the dialysis unit, acts as donor and acceptor solution. With an assay cycle of 262 seconds, the system allows a sample throughput of 14 samples per hour and yields precise results (rsd < 2%). Peroxidase (0.0512 IU) and 0.0384 IU of lactate oxidase promote the conversion of L(+)-lactate in 160 µL of sample, allowing its determination within the 0.25 to 2.5 g/L range. A detection limit of 0.074 g/L was calculated. Results are in good agreement with those obtained with the conventional method (Boehringer UV-Kit).