Ion-Exclusion HPLC Separation of Different Acids Using Zodiac HST OG Column

Organic acids were separated by ion-exclusion chromatography using the Zodiac HST OG column (250 × 4.6 mm). The mobile phase consisted of 25% acetonitrile and 75% water with 0.03% sulfuric acid. The method was run at a flow rate of 0.3 mL/min and monitored by UV detection at 210 nm.

The method enables effective separation of polar acidic compounds and is compatible with LC/MS detection. Four organic acids were baseline resolved under these conditions:

1. Maleic acid (pKa = 1.83)

2. Fumaric acid (pKa = 3.03)

3. Malic acid (pKa = 3.40)

4. Succinic acid (pKa = 4.16)

The separation is based on differences in acidity and structure, allowing precise analysis of organic acids in complex mixtures.