GPC column

Record: 491

Category: Specifications
Product: SB-803
Sample:

Question
I attached conditions and results of my compounds using OHpak SB-803 HQ column.
Can you suggest anything to increase resolution?

And can you recommend standard sample to calculate molecular weight in DMSO?

Answer
It is difficult to say if we can improve the resolution or not: Do you know if you are supposed to obtain symmetrical distribution of the compound?
It could be that the chromatogram is showing an “accurate” distribution of the compound.
From the chromatogram, I do not really think it is touching either (high or low) MW limits of the column, i.e., adding SB-802.5 or SB-804 will not do much.
You could add one more SB-803 but if your compounds do not have significant MW differences (say ~20K differences) they will not separate.
One thing you might want to try is to reduce the concentration of your sample, please see attached pdf.

Another thing that you may want to check is that if your sample is completely dissolved in pure DMSO solvent.
Please see below example.
http://shodex.net/index.php?seitenid=1&applic=139

Regarding the standards, I think PEG will be a good standard in your case.
Unfortunately we do not sell PEG, you may want to check Sigma or similar chemical supply companies.

 
 
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