Succinic Acid and Fumaric Acid

Succinic acid and fumaric acid were analyzed using RSpak KC-811. The elution time of succinic acid and fumaric acid largely changes according to eluent pH and column temperature. And, sometimes their peaks interfere the peaks of other substances. (Please refer to Effect of Column Temperature on Elution Volume (1))
Comparing (1), (2) and (3), it was confirmed that the elution order of succinic acid and fumaric acid changes according to the conditions.


Sample :
1. Succinic acid
2. Fumaric acid
3. Lactic acid
4. Formic acid

Columns      : Shodex RSpak KC-LG (8.0mmID*50mm) + KC-811 (8.0mmID*300mm) x 2
Eluent       : (1)2mM HClO4 aq.
               (2)2mM HClO4 aq./CH3CN=90/10
               (3)4mM HClO4 aq./CH3CN=90/10
Reagent      : 10-fold diluted ST3-R (for post-column method)
Flow rate    : 1.0mL/min
Detector     : VIS(430nm)
Column temp. : 60deg-C