Separation of Diacid Hydrophobic and Ion Exchange Modes

The Zodiac HST B column utilizes a combination of hydrophobic reversed-phase and anion-exchange mechanisms to effectively separate a range of diacids, including fumaric, benzoic, phthalic, naphthoic, and maleic acids. Modifying the acetonitrile concentration in the mobile phase can alter the elution order, notably reversing the peaks for naphthoic and maleic acids. This separation is achieved using a mobile phase consisting of water, acetonitrile (MeCN, ACN), and trifluoroacetic acid (TFA), with detection at 250 nm by UV.