By deST on Wednesday, July 10, 2002 - 02:10 pm:
I need a good HPLC-method for Doxazosin Mesylate (Assay).
I used:
DEA (or TEA 0.1% or 0,3%) pH 3,0 with Fosforic Acid : Acn (or MeOH); 1.0 mL/min; columns C-18 or CN; at 25oC, 30oC, 35oC, 40oC: but on all conditions my peak symmetry was very ugly!!! The posterior assimmetry is greater, and the reprodutibility is very bad.
Tanks,
deST
By Anonymous on Thursday, July 11, 2002 - 10:04 am:
aside from the method, your spelling needs help as well
By Gerhard Kratz on Thursday, July 11, 2002 - 10:57 pm:
Dear Anonymous, I guess you are American. How good is your French, Italian, Russian, or German??? Dear deST: what is the pK of your Doxa...???! What kind of C18 you use (encapped? with embedded polar groups? etc.! I think it might be not a problem of column temperature, more it could be a problem of pH in your mobile phase? Please give us some more information. And don't worry about your English! Regards
Gerhard
By Joe Runkle on Friday, July 12, 2002 - 09:25 am:
Looking at the structure of doxazosin, your mobile phase composition and pH seems to be a reasonable starting point. As Gerhard asked, what column are you using? Also, how is your retention (is your peak well retained and of poor shape)? Post what information you have, I'd be happy to try to help. Good Luck.
Joe
By phill on Wednesday, July 24, 2002 - 03:11 am:
We use an SCX column with 0.2% perchloric acid in methanol (v/v) as mobile phase at ambient temperature - it works very well !
By deST on Wednesday, July 24, 2002 - 02:35 pm:
Dear Phill
What is the supplyer of SCX column?
By deST on Thursday, July 25, 2002 - 09:12 am:
Dear Phill
Tanks for your help. I have supplyer of SCX-column.
deST