dextran sulfate analysis

Record: 501

Category: Applications
Product: KS-804
Sample:

Question
I tried using NH4OH (0.001 M NH4OH) in my mobile phase, still the compound is excluding out.
I try to use ammonium acetate but its fluding the CAD, it might be replacing sodium?
Do you have any suggestions using this column or any other columns you suggest instead?

Answer
We think 0.001 M NH4OH is too weak to suppress the ionic repulsion effect. At least 20 mM will probably be required. We are sorry about the acetate, we were not aware that it causes to remove the Na+ ion. I would suggest regenerating the column with 0.01N NaOH (0.5 mL/min for 30 min or so, of course detaching the detector) to bring it back to the original condition before starting 20 mM NH4OH solvent.
Please let us know your progress. Just to let you know that I will be taking a vacation between 1/18-27. If you need assistance during that time, Takashi (cc-ed in this email) should be able to help you.

 
 
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