VOLATILE ORGANIC COMPOUNDS BY VACUUM DISTILLATION IN COMBINATION WITH GAS CHROMATOGRAPHY/MASS SPECTROMETRY (VD/GC/MS) is the best way to separate these 2 peaks ..
Dear Seunghyun Jang , despite boiling points of MMA and dioxane are similar, you can easily separate their GC peaks if you use the right column: for your application, a DB-624 (or equivalent) should perfectly work. All the best. Valerio