Single-Run Separation and Determination of Aliphatic and Aromatic Carboxylic Acids in Wine and Human Urine Samples by Ion-Exclusion Chromatography

This work is focused on developing a new chromatographic method with UV detection for the separation and determination of thirty-two carboxylic aliphatic and/or aromatic acids in a single run. Ion-exclusion chromatography with a silica based, modified with C18, analytical column Alltech Prevail (TM) organic acid 5 A mu m (150 mm x 4.6 mm I.D) was used for the solving of this problem. The developed method was based on ion-exclusion and/or hydrophobic interaction chromatographic separation mechanism. The effect of the concentrations of phosphate buffer and its pH as well as the column temperatures on the retention of the test acids has been investigated. Gradient elution of the mobile phase composed of aqueous phosphate buffer and methanol was used to achieve a required separation of carboxylic acids within 45 min. All measurements were done at 220 nm. Column temperature was set at 25 +/- A 0.1 A degrees C. The LOD values for organic acids range from 0.002-2.224 mg L-1. The repeatability of the procedure developed is characterized by the RSD, which varied between 0.52 and 2.85 % for the peak area. The proposed method was successfully applied for the determination of aliphatic and aromatic acids in dry white wine and human urine samples.