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phthalimide analysis
Posted: Wed Jul 01, 2009 6:39 pm
by praveenpaliwal
It is very important for me can any body tell me aot HPLC analysi of Phthalimide . I need some litratures also for such type of analysis.
Praveen
Posted: Fri Jul 03, 2009 6:25 pm
by praveenpaliwal
can I analysed this compound on KH2pO4 buffer
praveen
Posted: Fri Jul 03, 2009 7:07 pm
by Don_Hilton
There seem to be a number of references out there, for instance if your interst is pesticide residue related, an internet search of "HPLC folpet Phthalimide" turns up about 45 hits which look like good leads. If you tell what your application is - it may get a better focused response.
Posted: Fri Jul 03, 2009 7:53 pm
by mohan_2008
Pthalimide is a base with a pKa ~ 8.3
HPLC method is pretty simple.
Posted: Sat Jul 04, 2009 8:12 am
by Uwe Neue
Phthalimide is an ACID with a pKa of 8.3. It is not ionized under acidic conditions. I would use acetic acid/acetate buffer.
phthalimide
Posted: Mon Jul 06, 2009 3:33 pm
by praveenpaliwal
I am quite satisfide by Dr. UWE-but Mr. Moahn say that it is base . I am sure that it is acid because of two high electronegative charged oxygen atoms.
Due two this the lon pair of elctrone on nitrgen atom is involved in the 5 membered ring and may be released the proton. Am I right please suggest me.
I am using the salt solution of 0.02M KH2PO4 along with methanol. I got sahrp peak .
" My basic questions is about such type of moluecule which involves phthalimide so some type of litrature if available please tell me.
Another one I need the pK value table for such type of compound.
Please tell about tha same.
Best regards
praveen
Posted: Mon Jul 06, 2009 8:45 pm
by Vlad Orlovsky
Uwe is right, phtjalimide is acid. I guess Mohan is making his statement based on misconseption of if compound pKa is above 6 then it is base, if pKa is below 5 then it is acid.
I would say that for chromatography point of few phthalimide is neutral, you are not going to see ion-exchange inetraction. Any C18 column will work at lower organic (5-20%), pH of the mobile phase might affect peak shape and may be a liitle bit retention due to more polar nature of phtalimide above pH 9 (if you ever going to use it for this particular compound)