Why will fluorescein elute from an alumina-packed column when NaOH is added as a solvent? Why will methylene blue not elute using NaOH as a solvent?
- Is it because fluorescein is polar, therefore it will be more soluble in the NaOH? Or is it that it is slightly acidic and adding NaOH will create Al-OH groups in the alumina, causing the fluorescein to adsorb better to the stationary phase instead of the mobile phase?