Separation modes such as anion-exchange, ion-exclusion, and reversed-phase have been used in the analysis of organic acids by HPLC. In recent years, more and more cases have been analyzed using ion-exclusion modes with columns dedicated to organic acids.
However, in order to improve the separation in ion exclusion mode, it is necessary to lengthen the analysis time.
In this study, an ion exchange column was used.
Analyses were conducted using a combination of "ion exclusion mode" and "hydrophobic interaction mode" with a reversed-phase column. The use of two general-purpose-size columns with different separation modes (250 x 4.6 mm I.D.) enables the rapid simultaneous analysis of 8 components including phosphoric and organic acids.