By Lya Wise on Thursday, July 1, 1999 - 02:33 pm:
We are having trouble with our Hydrocodone Bitartrate Assay by HPLC. We have lost response in both the standards and samples. The mobile phase consists of 4.44g of Docusate Sodium in 600ml of MeOH, 360ml of H2O, 40ml of THF, and 1ml of H3PO4. We have tried different lots of the solvents, tried different columns, used 2 different lots of standard, used 2 different samples, and used 3 different instruments. If you have any suggestions at all of what to try, please email us! Thank you, Pharmaceutical Associates, Inc.
By Sue on Friday, July 2, 1999 - 07:42 am:
A loss of response like this often indicates that the analytes are degrading in the sample solvent.
Changing the pH of the sample solutions might help.
By lisa on Monday, July 5, 1999 - 06:09 am:
Have you tried running the samples/standards by another method (say, GC/MS) to assure that the standards are still good?
I don't have an LC method specific for hydrocodone, but I do have a method for other basic drugs in which hydrocodone comes after about 3-4 minutes at 85% pH4 phosphate "buffer"* and 15% ACN, flow=1, column is 150x4.6 Micra SCD-100 ("short chain", silica based column). I'm not looking at the chromatograms right now, but I think that's the correct MP composition.
*NOTE that this is NOT a proper buffer, as 4 is outside the buffering range of phosphate (but it works for me!!)
By arizona on Saturday, December 4, 1999 - 02:57 pm:
I need to run a hydrocodone quant in syrup, but want to use GC/MS followed by SPE. I am not a HPLC user, although we have. Do you have any recommendations or procedural guidelines for the sample prep. for gc/ms
Posting is currently disabled in this topic. Contact your discussion moderator for more information.