questions about size exclusion chromatography

Record: 345

Category: Specifications
Product: SB
Sample:

Question
We currently have OHpak SB-800 HQ series columns (models 803HQ to 806 HQ). We work on block copolymers PEG-chitosan and we would like to separate the copolymers from the precursors. The final copolymer is 14000 g / mol and the precursors are chitosan (polysaccharide positively charged with a mass of 10000) and PEG (2000 g/mol). Is the purchase of a column SB-SB-802 or 802.5 will help us? If yes, which one is preferable?
Are other types of columns that could be considered for this separation?

Answer
For the separation of two compounds having MW of 14,000 and 10,000 g/mol, it should be the working range of SB-803 HQ… The exclusion limit (pullulan standard) for SB-802 HQ and SB-802.5 HQ are 4,000 and 10,000 Da respectively, so theoretically they are too small for your target. Have you tried running your sample with your current system? As you know MW is only an indicator of compound size and it may be influenced by the mobile phase as well.

If you have analyzed your sample with SB-803 HQ, would you be able to share your chromatogram and analytical conditions? I would like to see how much level of separation you are currently obtaining and from there may be we can recommend a way to improve it. Thank you.

 
 
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