SB-807 application Shodex order form

Record: 403

Category: Column Problem
Product: SB
Sample:

Question
As I begin to work with the SB 807 HQ column a few questions have arisen

When we talked previously we had discussed replacing the SB 806 with the SB 807—
If I put the 807 first in series with the 805 and 803 it seems as though I will exceed the maximum pressure on the 807–72 psi ( 0.5 MPa)
I know the 806-805-803 series runs pressure of over 300 psi

Can you provide your thoughts and insights on this?

If I place the SB807 as the last column—it should keep the pressure across that column down but it doesn’t seem like the other smaller pore columns are even necessary?

Answer
The maximum pressure stated is per column, so going over 0.5MPa when using three columns will not be a problem (Is this what you meant?).
As long as the flow rate you use does not create over 0.5MPa pressure when SB-807 HQ is used alone.

We generally do recommend to connect SEC columns in the order of bigger pore size to smaller ones, however some say that there will be no difference in separation efficiency even the order is reversed..
If you could use only SB-807 HQ to accurately determine the molecular weight of your analytes, I think it will be better than combining other columns in series.
Separation wise, SB-807 HQ definitely separates ~6M and 300K Da compounds by itself. Most likely it will provide accurate MW information for 6M compound, but 300K Da is very close to the lower limit of SB-807 HQ, thus the MW information collected may not be as accurate as it supposed to be. I would suggest you to try using SB-807 HQ alone first and then compare the MW information (especially for the lower part) with the result from your previous method.

 
 
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