Determination of Organic Acids in White Wines by RP-HPLC

Mira Kordiš-Krapež¹*, Veronika Abram², Milica Kač² and Stanka Ferjančić<sup>2 

1</sup>BIA, d.o.o., Teslova 30, SI-1000 Ljubljana, Slovenia
²Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia 

Article history:
Received October 5, 2000 
Accepted March 23, 2001

Key words:
organic acids, RP-HPLC analysis, white wine

Summary:
The chromatographic conditions for the optimal separation of tartaric, malic and citric acids on a LiChrosorb RP-18 column (10
μm, 25 cm x 4.0 mm i.d.) at 210 nm were determined. The optimized RP-HPLC method (mobile phase: c(H₃PO₄) = 6 10^–3 mol/L, pH=2.1, flow rate 1.0 mL/min) was validated. Calibration curves were linear for all three acids in the concentration range tested; r² was better than 0.999. RSDs for tartaric and malic acids were within  ±2 %, and for citric acid  ±10.4 %. The average relative error for tartaric acid was 3.2 %, for malic acid 2.5 % and for citric acid 6.0 %. Ethanol caused an insignificant negative response at t_R = 5.69 min, whereas glucose and fructose eluted in the void volume. According to the validation results, and from analysis of wine samples, the described HPLC method was found adequate for routine determination of tartaric and malic acids and to some extent also of citric acid in dry, semi-dry, semi-sweet and sweet white wines.

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