-
- admin
- Site Admin
-
- Posts: 647
- Joined: Wed Aug 11, 2004 12:19 am
By sandra on Thursday, August 5, 2004 - 10:23 am:
We are applying a YMC ODS-A column (4,6 mm x 15 cm, 3 mm) in the analysis of Paclitaxel Injection according to current USP method for determining the Limit of Degradation Products. When we proved the method for the first time, we obtained a resolution between paclitaxel and related compound B near 1.9 (the requirement is: not less than 1.2). But now, after approximately 50 runs of about 80 minutes each one, the peaks does not separate, and the retention times of the peaks are smaller than the first ones. An important fact is that the paclitaxel injection contains about 50% (w/w) of Cremophor (Polyoxyl 35 Castor Oil). The Cremophor produces two broad peaks that appear at 50 and 55 minutes. We think that it may be causing column bleeding, or it may be retained inside the column.
May be there is someone working with this products that could help me to solve this problem. Regards!
-------------------------------------------------------------------------------------------------------
By Uwe Neue on Thursday, August 5, 2004 - 02:35 pm:
Have you tried to wash the possible contaminat off with 100% organic? Try your organic solvent first, if this does not work, try THF.
-------------------------------------------------------------------------------------------------------
By JM on Thursday, August 5, 2004 - 11:02 pm:
wash the column after each run in 100 % ACN for 5 min. this can be programed in your gradient cycle. After few days of analysis wash the column with 100 % methanol for 30 min.
-------------------------------------------------------------------------------------------------------
By sandra on Monday, August 9, 2004 - 04:55 am:
Thank you very much!!
We are applying a YMC ODS-A column (4,6 mm x 15 cm, 3 mm) in the analysis of Paclitaxel Injection according to current USP method for determining the Limit of Degradation Products. When we proved the method for the first time, we obtained a resolution between paclitaxel and related compound B near 1.9 (the requirement is: not less than 1.2). But now, after approximately 50 runs of about 80 minutes each one, the peaks does not separate, and the retention times of the peaks are smaller than the first ones. An important fact is that the paclitaxel injection contains about 50% (w/w) of Cremophor (Polyoxyl 35 Castor Oil). The Cremophor produces two broad peaks that appear at 50 and 55 minutes. We think that it may be causing column bleeding, or it may be retained inside the column.
May be there is someone working with this products that could help me to solve this problem. Regards!
-------------------------------------------------------------------------------------------------------
By Uwe Neue on Thursday, August 5, 2004 - 02:35 pm:
Have you tried to wash the possible contaminat off with 100% organic? Try your organic solvent first, if this does not work, try THF.
-------------------------------------------------------------------------------------------------------
By JM on Thursday, August 5, 2004 - 11:02 pm:
wash the column after each run in 100 % ACN for 5 min. this can be programed in your gradient cycle. After few days of analysis wash the column with 100 % methanol for 30 min.
-------------------------------------------------------------------------------------------------------
By sandra on Monday, August 9, 2004 - 04:55 am:
Thank you very much!!
