When using the multi-mode ODS Scherzo C18 column from IMTAKT for eluting ionic substances, it is important to consider not only the organic solvent but also the "salt concentration and ionic strength" of the mobile phase. As shown in the left figure, increasing the salt concentration for the three types of Scherzo columns results in decreased retention for both anionic and cationic compounds.
Among the three columns, SS-C18, which has a high amount of strong ion ligands, shows the highest retention at the same salt concentration, followed by SM-C18 with moderate amounts of weak ion ligands, and SW-C18 with a small amount of strong ion ligands. Depending on the ionic strength of the target substances, the optimal column can be selected from the three types of Scherzo columns.

When using multi-mode ODS Scherzo columns for eluting ionic substances, the "pH" conditions of the mobile phase are crucial. The retention significantly changes depending on whether the elution is carried out at a neutral pH using ammonium acetate or ammonium formate or under acidic conditions with formic acid. SS-C18 and SW-C18, which contain strong ion ligands, show increased retention when the pH of the mobile phase is lowered. On the other hand, SM-C18, which has weak ion ligands, shows decreased retention for basic substances at low pH because the dissociation of anion ligands is suppressed, preventing ion-exchange interactions.