The organic acids quinic, malic, shikimic and citric were separated on a packed reverse phase fused-silica capillary column using 0.01 M K₂HPO₄/H₃PO₄ at pH 2.7 as eluent at a flow rate of 2 μL/min, and determined with UV detection. Conventional liquid chromatographicequipment was adapted for such purposes.

The organic acids were able to be separated with detection limits of 2.4, 2.1, 0.04 and 2.9 ng, respectively. Application of the proposed method to the quantification of organic acids in apple juice is reported.