best chemical for the most pure?

im wondering more about chemicals like butane, ether, and the likes. if ether was equally as easy to obtain (in my case, its possible at times), would it be better than butane? or any other chemicals for that matter?

and note, i am only doing this for fun, and what i am trying to acclompish is the purest form of thc possible. i dont really care about the cost, im not trying to make any profit. i am more interested in the chemistry of it all, and seeing how well i can do it. i guess partly because i want to be a chemist of some sort.

and 1 random question to add-what if i do an iso extraction with just keif. keep in mind, i dont care if its "worth it" or not. i am interested in the results.

http://www.erowid.org/plants/cannabis/cannabis_chemistry2.shtml

guess i should do more research first....that was too easy to find. now all i have to do is wait til i have a lab, or at least access to one...

ok, i reread the article, and the process is assuming you have pure oil to start with....so, kind of back to my original question, how do i get the purest hash oil?

I use 99% isopropyl alcohol, $8.00/L here. Works for me. I like it because it's not as explosive as butane or ether.