Chromatography Forum

hi

just came across the UPLC SEC column released by WATERS...
so what is your take on it??can this UPLC/UHPLC approach help??

The question is on the grounds on chrompatographic science,

I don't see the reason for "why not".
Is there something more concrete that worries you?

Best Regards

hi
well a recent article in "The column" triggered the question in my mind

the article
http://chromatographyonline.findanalyti ... ryId=48334

OK – I’ve just read the article, which is full of misconceptions.

I’ll address some of them just for the sake of illustration:

1. It is mentioned that unlike RP and other techniques the GPC runs in a non-gradient mode. I can’t regard this fact as a valid rationale for small particles’ inability to result in higher efficiency. There are many upon many isocratic RP methods that benefit from the smaller particles’ higher efficiency! So, falls statement 1.

2. Then it’s mentioned that it is difficult to manufacture stable small particles for GPC stationary phase. But what does it have to do with these particles’ ability to deliver the higher efficiency? If somebody is able to manufacture them, I would make use of them and achieve the higher efficiency I’m after – if it’s the goal. So falls statement 2.

3. Then the authors teach us that one of the most important parameters is the stationary phase’ “accessible volumeâ€

The statements in this article are largely based on polymer SEC using polymeric particles. The UPLC SEC column from Waters is based on a silica-type hard particle that can withstand the UPLC pressures. Furthermore, SEC is operating in general at lower linear velocities than HPLC/UPLC, so the requirements are less stringent.

Before we started our UPLC SEC project, we also were unsure about shear degradation of the analytes that were targeted, specifically IgG dimers and trimers. Therefore my very first experiment in this project was to make sure that such analytes survived the UPLC SEC. It did, and the project progressed, and a short time ago, the UPLC SEC columns were introduced.

So, the people at Waters have done the necessary homework, and UPLC SEC is not a pipedream.

To go back to the argument that SEC has its limitations: it does, if you are working with polymer-based particles...

Uwe:

What's with the caveat in the brochure that says these columns are licensed for exclusive use with the Waters Acquity UPLC?

SEC is happening at k' values less than 0. Extra-column effects will play a giant role. We want to make sure that you put these columns on an instrument that has the capability to run them.