By Jan on Wednesday, January 21, 2004 - 02:15 am:
Dear All,
USP and EP describe SEC for molecular weigth distribution of Dextrans. While USP needs 3 columns with L38 packing (a methacrylate-based size-exclusion packing for water-soluble samples), the European Pharmacopoeia wants 1 agarose column, or a serie of hydroxylated polyether columns (quite vague if you ask me).
I checked with TSK, Shodex, they all offer columns that will do the job (so they say), but I really want to find someone who is doing this USP or EP test and can tell me what column(s) she/he is using. These are expensive colums and I just want to make the right choice.
Thanks for your help
Jan
By Uwe Neue on Wednesday, January 21, 2004 - 04:12 pm:
In SEC, the only way in which one can improve resolution is through the number of columns and the particle size. If you want to match the resolution required by USP, I would use the number of columns required and the particle size required. If the EP is doing this on a single agarose column, I would rather stick with the USP approach, since the USP approach is expected to give higher resolution. Now nobody can blame me to have selected an inferior and unsuitable method.
For the USP test, you can usually find out, which column(s) they have qualified that work for their assay.