[morgogs]

So I have a basic understanding of Fluorescein. I'm doing this as my Chemistry project at school, but I feel like I need to know more about it and I can't find much information on it. I know that it forms the Sodium salt when in aqueous NaOH solution, which is very water soluble, and that when in acidic conditions it will form its free acid (?) form which has a very low solubility. What I don't understand are all of its different ion forms, like the monoanion, dianion, lactone, and cation. Which of these is fluorescent? What pH do these form in? Once I've made the Na salt in aqueous solution, how do I extract it? Is the best way for me to purify the free acid form to dissolve my crude product in NaOH solution, filter, acidify, evaporate the water, then filter it and rinse it? If there's any more information you think I should know, please let me know.

Thanks a lot

[AWK]

All the needed information you can find in your textbook (probably)
If not, search English Wikipedia and google: fluorescein pH