Good retention and peak shapes have been observed for similar compounds.
Methacrylic acid is similar in structure to acrylic acid, which can be well-retained with a mobile phase of DI water + 0.1% formic acid and a Bidentate C18 column.
Dodecyl benzene sulfonic acid has some of the same functional groups as docusate sodium, which also has a sulfonate group. The latter was observed to elute with a good peak shape using a gradient method and the Cogent Bidentate C18™ column. Dodecyl benzene sulfonic acid by itself should be suitable for the Diamond Hydride column as well, using an ammonium acetate-based mobile phase.
A gradient starting at high water (to retain the methacrylic acid) and ending at significant organic (to elute the dodecyl benzene sulfonic acid) can be used to retain both compounds. Since a Bidentate C18™ column was used for the two compounds above, it should be suitable for a separation of methacrylic acid and dodecyl benzene sulfonic acid as well. The Cogent Phenyl Hydride™ column would also be suitable.