By Raman.N on Monday, May 17, 2004 - 02:46 am:
Hai,
Can any body sugest an HPLC method for Tertiary butyl ester of indoline carboxylic acid (Molecular weight 225)
Presently I am using 10 mM Diammonium phosphate buffer combined with 0.1% Tetrabutylammonium hydrogen sulphate (pH at 6) and acetonitrile. Column C8 and detector at 210 nm.
The problem is I am getting more number of peaks and our lab people are not accepting that their product is inferior.
So any body suggest that any alternative method.
By Anonymous on Monday, May 17, 2004 - 06:07 am:
Are you using p.a. qualitiy salts?
Try sulfuric acid (0.5% of 0.5M in water, pH 2.5) instead of buffers. If the number of peaks stays the same, the product is most likely not as pure as the people from production hopes...
By Anonymous on Tuesday, May 18, 2004 - 05:55 am:
Raman,
If you can demonstrate that your blank injections are devoid of these "extra" peaks that should be good evidence that the peaks are in the sample. To help insure this, the sample solvent would be best if it was actual mobile phase if possible.
Regards,
Mark
P.S. I always love it when production says (without any proof or data) that the analytical labs answers HAVE to be wrong!
By Anonymous on Tuesday, May 18, 2004 - 06:19 pm:
Is it as a bulk or in a dosage form? If it is the second and your mobile phase is OK (HPLC grade), try inject placebo of your sample.
If possible, try using another wavelength (>205 or 210 nm).