Determination of Tartaric Acid and the Sum of Malic and Citric Acids in Grape Juices by Potentiometric Titration

Application of a linear algebraic method to the potentiometric titration of a mixture of tartaric and malic acids makes it possible to determine the individual concentrations of both acids in the same sample. These 2 acids have also been determined in grape juice free of citric acid after their separation from the juice matrix by precipitation as barium salts, followed by selective solubilization. It is also possible to determine tartaric acid and the sum of malic acid and citric acid in grape juice when the latter is present.