guard column

Record: 305

Category: Specifications
Product: SEC
Sample:

Question
compatability with the mixed bed columns with the single pores. We noticed, for example, that when we connect the SB-806M with SB-804 and SB-802 that we get a shoulder on the narrow PEO standard, while we don’t get the shoulder when using the SB-806M on their own or the their single pores on their own. We also noticed the same behaviour when conneting the KF-806M with KF-804L and KF-803L.

Answer
Our technical notebook for LF series column shows several examples comparing the combination of conventional (single pore-sized columns), mixed gel type, and LF series.
http://shodex.net/data/downloads/Shodex_Technical_Notebook_1_LF_%28GPC%29.pdf

You can see when combining the conventional type will create shoulders. This is improved a lot when mixed gel type was used however will still suffer slightly. We do not have an application combining mixed gel type and the conventional type, but similar shoulder problem can be expected. Thus if you need to improve the separation, we recommend using multiple number of mixed gel type column…although I understand in some case that the user wants to improve the separation of specific MW range. In that case, I’m sorry to say, but there’s nothing really we can do to prevent the shoulder to appear.

 
 
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