N. Kiba et al., DETERMINATION OF L-MALATE IN WINE BY FLOW-INJECTION WITH CO-IMMOBILIZED MALATE-DEHYDROGENASE OXALOACETATE DECARBOXYLASE, Talanta, 40(8), 1993, pp. 1163-1165
A method for determination of L-Malate in wine is described. Malate de
hydrogenase and oxaloacetate decarboxylase were immobilized on poly (v
inyl alcohol) beads and incorporated in a flow-injection system with f
luorescence detection. Sample solution (50 mul) was injected into the
carrier stream [4mM NAD+ in glycine buffer (pH 10.0)]. The fluorescenc
e based on the NADH formed could be directly related to the amount of
malate. The calibration graph was linear over the range 0.4-300 muM. T
he detection limit was 0.2 muM. Sampling throughout was 25 samples/hr.